`vexpr': fix error message for shift operators

[s-mailx.git] / nail.h

/*@ S-nail - a mail user agent derived from Berkeley Mail.
 *@ Header inclusion, macros, constants, types and the global var declarations.
 *@ TODO Place in include/, split in object-based subheaders.  And please: sort.
 *
 * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
 * Copyright (c) 2012 - 2017 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
 */
/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifndef n_NAIL_H
# define n_NAIL_H

/*
 * Mail -- a mail program
 *
 * Author: Kurt Shoens (UCB) March 25, 1978
 */

#include <mk-config.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>

#ifdef HAVE_GETTIMEOFDAY
# include <sys/time.h>
#endif

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#ifdef HAVE_C90AMEND1
# include <wchar.h>
# include <wctype.h>
#endif
#ifdef HAVE_DEBUG
# include <assert.h>
#endif
#ifdef HAVE_ICONV
# include <iconv.h>
#endif
#ifdef HAVE_REGEX
# include <regex.h>
#endif

#ifdef HAVE_XSSL_MD5
# include <openssl/md5.h>
#endif

/* Many things possibly of interest for adjustments have been outsourced */
#include <config.h>

/* Special FD requests for n_child_run(), n_child_start() */
#define n_CHILD_FD_PASS -1
#define n_CHILD_FD_NULL -2

/* Colour stuff */
#ifdef HAVE_COLOUR
# define n_COLOUR(X) X
#else
# define n_COLOUR(X)
#endif

/*  */
#define n_FROM_DATEBUF 64        /* Size of RFC 4155 From_ line date */
#define n_DATE_DAYSYEAR 365u
#define n_DATE_NANOSSEC (n_DATE_MICROSSEC * 1000)
#define n_DATE_MICROSSEC (n_DATE_MILLISSEC * 1000)
#define n_DATE_MILLISSEC 1000u
#define n_DATE_SECSMIN 60u
#define n_DATE_MINSHOUR 60u
#define n_DATE_HOURSDAY 24u
#define n_DATE_SECSHOUR (n_DATE_SECSMIN * n_DATE_MINSHOUR)
#define n_DATE_SECSDAY (n_DATE_SECSHOUR * n_DATE_HOURSDAY)

/* Network protocol newline */
#define NETNL           "\015\012"
#define NETLINE(X)      X NETNL

/*
 * OS, CC support, generic macros etc.
 */

#define n_ISPOW2(X) ((((X) - 1) & (X)) == 0)
#define n_MIN(A,B) ((A) < (B) ? (A) : (B))
#define n_MAX(A,B) ((A) < (B) ? (B) : (A))
#define n_CLIP(X,A,B) (((X) <= (A)) ? (A) : (((X) >= (B)) ? (B) : (X)))
#define n_ABS(A) ((A) < 0 ? -(A) : (A))

/* OS: we're not a library, only set what needs special treatment somewhere */
#define n_OS_DRAGONFLY 0
#define n_OS_OPENBSD 0
#define n_OS_SOLARIS 0
#define n_OS_SUNOS 0

#ifdef __DragonFly__
# undef n_OS_DRAGONFLY
# define n_OS_DRAGONFLY 1
#elif defined __OpenBSD__
# undef n_OS_OPENBSD
# define n_OS_OPENBSD 1
#elif defined __solaris__ || defined __sun
# if defined __SVR4 || defined __svr4__
#  undef n_OS_SOLARIS
#  define n_OS_SOLARIS 1
# else
#  undef n_OS_SUNOS
#  define n_OS_SUNOS 1
# endif
#endif

/* CC */
#define CC_CLANG           0
#define PREREQ_CLANG(X,Y)  0
#define CC_GCC             0
#define PREREQ_GCC(X,Y)    0
#define CC_TCC             0
#define PREREQ_TCC(X,Y)    0

#ifdef __clang__
# undef CC_CLANG
# undef PREREQ_CLANG
# define CC_CLANG          1
# define PREREQ_CLANG(X,Y) \
   (__clang_major__ + 0 > (X) || \
    (__clang_major__ + 0 == (X) && __clang_minor__ + 0 >= (Y)))
# define __EXTEN           __extension__

#elif defined __GNUC__
# undef CC_GCC
# undef PREREQ_GCC
# define CC_GCC            1
# define PREREQ_GCC(X,Y)   \
   (__GNUC__ + 0 > (X) || (__GNUC__ + 0 == (X) && __GNUC_MINOR__ + 0 >= (Y)))
# define __EXTEN           __extension__

#elif defined __TINYC__
# undef CC_TCC
# define CC_TCC            1
#endif

#ifndef __EXTEN
# define __EXTEN
#endif

/* Suppress some technical warnings via #pragma's unless developing.
 * XXX Wild guesses: clang(1) 1.7 and (OpenBSD) gcc(1) 4.2.1 don't work */
#ifndef HAVE_DEVEL
# if PREREQ_CLANG(3, 4)
#  pragma clang diagnostic ignored "-Wassign-enum"
#  pragma clang diagnostic ignored "-Wdisabled-macro-expansion"
#  pragma clang diagnostic ignored "-Wformat"
#  pragma clang diagnostic ignored "-Wunused-result"
# elif PREREQ_GCC(4, 7)
#  pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#  pragma GCC diagnostic ignored "-Wunused-result"
#  pragma GCC diagnostic ignored "-Wformat"
# endif
#endif

/* For injection macros like DBG(), n_NATCH_CHAR() */
#define COMMA           ,

#define EMPTY_FILE()    typedef int n_CONCAT(avoid_empty_file__, n_FILE);

/* Pointer to size_t */
#define PTR2SIZE(X)     ((size_t)(uintptr_t)(X))

/* Pointer comparison (types from below) */
#define PTRCMP(A,C,B)   ((uintptr_t)(A) C (uintptr_t)(B))

/* Ditto, compare (maybe mixed-signed) integers cases to T bits, unsigned;
 * Note: doesn't sign-extend correctly, that's still up to the caller */
#define UICMP(T,A,C,B)  ((ui ## T ## _t)(A) C (ui ## T ## _t)(B))

/* Align something to a size/boundary that cannot cause just any problem */
#define n_ALIGN(X) (((X) + 2*sizeof(void*)) & ~((2*sizeof(void*)) - 1))
#define n_ALIGN_SMALL(X) \
   (((X) + n_MAX(sizeof(size_t), sizeof(void*))) &\
    ~(n_MAX(sizeof(size_t), sizeof(void*)) - 1))

/* Members in constant array */
#define n_NELEM(A) (sizeof(A) / sizeof((A)[0]))

/* sizeof() for member fields */
#define n_SIZEOF_FIELD(T,F) sizeof(((T *)NULL)->F)

/* Casts-away (*NOT* cast-away) */
#define n_UNUSED(X) ((void)(X))
#define n_UNCONST(P) ((void*)(uintptr_t)(void const*)(P))
#define n_UNVOLATILE(P) ((void*)(uintptr_t)(void volatile*)(P))
/* To avoid warnings with modern compilers for "char*i; *(si32_t*)i=;" */
#define n_UNALIGN(T,P) ((T)(uintptr_t)(P))
#define n_UNXXX(T,C,P) ((T)(uintptr_t)(C)(P))

/* __STDC_VERSION__ is ISO C99, so also use __STDC__, which should work */
#if defined __STDC__ || defined __STDC_VERSION__ /*|| defined __cplusplus*/
# define n_STRING(X) #X
# define n_XSTRING(X) n_STRING(X)
# define n_CONCAT(S1,S2) n__CONCAT_1(S1, S2)
# define n__CONCAT_1(S1,S2) S1 ## S2
#else
# define n_STRING(X) "X"
# define n_XSTRING STRING
# define n_CONCAT(S1,S2) S1/* won't work out */S2
#endif

#if defined __STDC_VERSION__ && __STDC_VERSION__ + 0 >= 199901L
# define n_FIELD_INITN(N) n_CONCAT(., N) =
# define n_FIELD_INITI(I) [I] =
#else
# define n_FIELD_INITN(N)
# define n_FIELD_INITI(N)
#endif

#if defined __STDC_VERSION__ && __STDC_VERSION__ + 0 >= 199901L
# define n_VFIELD_SIZE(X)
# define n_VSTRUCT_SIZEOF(T,F) sizeof(T)
#else
# define n_VFIELD_SIZE(X) \
  ((X) == 0 ? sizeof(size_t) \
   : ((ssize_t)(X) < 0 ? sizeof(size_t) - n_ABS(X) : (size_t)(X)))
# define n_VSTRUCT_SIZEOF(T,F) (sizeof(T) - n_SIZEOF_FIELD(T, F))
#endif

#ifndef HAVE_INLINE
# define n_INLINE static
#endif

#undef __FUN__
#if defined __STDC_VERSION__ && __STDC_VERSION__ + 0 >= 199901L
# define __FUN__        __func__
#elif CC_CLANG || PREREQ_GCC(3, 4)
# define __FUN__        __extension__ __FUNCTION__
#else
# define __FUN__        n_empty /* Something that is not a literal */
#endif

#if defined __predict_true && defined __predict_false
# define n_LIKELY(X) __predict_true(X)
# define n_UNLIKELY(X) __predict_false(X)
#elif CC_CLANG || PREREQ_GCC(2, 96)
# define n_LIKELY(X) __builtin_expect(X, 1)
# define n_UNLIKELY(X) __builtin_expect(X, 0)
#else
# define n_LIKELY(X) (X)
# define n_UNLIKELY(X) (X)
#endif

#undef HAVE_NATCH_CHAR
#if defined HAVE_SETLOCALE && defined HAVE_C90AMEND1 && defined HAVE_WCWIDTH
# define HAVE_NATCH_CHAR
# define n_NATCH_CHAR(X) X
#else
# define n_NATCH_CHAR(X)
#endif

/* Compile-Time-Assert
 * Problem is that some compilers warn on unused local typedefs, so add
 * a special local CTA to overcome this */
#if defined __STDC_VERSION__ && __STDC_VERSION__ + 0 >= 201112L
# define n_CTA(T,M) _Static_assert(T, M)
# define n_LCTA(T,M) _Static_assert(T, M)
#else
# define n_CTA(T,M)  n__CTA_1(T, n_FILE, __LINE__)
# define n_LCTA(T,M) n__LCTA_1(T, n_FILE, __LINE__)
#endif
#define n_CTAV(T) n_CTA(T, "Unexpected value of constant")
#define n_LCTAV(T) n_LCTA(T, "Unexpected value of constant")

#ifdef n_MAIN_SOURCE
# define n_MCTA(T,M) n_CTA(T, M);
#else
# define n_MCTA(T,M)
#endif

#define n__CTA_1(T,F,L)   n__CTA_2(T, F, L)
#define n__CTA_2(T,F,L) \
   typedef char ASSERTION_failed_in_file_## F ## _at_line_ ## L[(T) ? 1 : -1]
#define n__LCTA_1(T,F,L)  n__LCTA_2(T, F, L)
#define n__LCTA_2(T,F,L) \
do{\
   typedef char ASSERTION_failed_in_file_## F ## _at_line_ ## L[(T) ? 1 : -1];\
   ASSERTION_failed_in_file_## F ## _at_line_ ## L __i_am_unused__;\
   n_UNUSED(__i_am_unused__);\
}while(0)

#define n_UNINIT(N,V)     N = V

/* Create a bit mask for the bit range LO..HI -- HI can't use highest bit! */
#define n_BITENUM_MASK(LO,HI) (((1u << ((HI) + 1)) - 1) & ~((1u << (LO)) - 1))

#undef DBG
#undef NDBG
#ifndef HAVE_DEBUG
# undef assert
# define assert(X)      n_UNUSED(0)
# define DBG(X)
# define NDBG(X)        X
# define DBGOR(X,Y)     Y
#else
# define DBG(X)         X
# define NDBG(X)
# define DBGOR(X,Y)     X
#endif

/* Translation (init in main.c): may NOT set errno! */
#undef _
#undef N_
#undef V_
#define _(S)            S
#define N_(S)           S
#define V_(S)           S

/*
 * Types TODO v15: n_XX_t
 */

#ifdef UINT8_MAX
# define UI8_MAX        UINT8_MAX
# define SI8_MIN        INT8_MIN
# define SI8_MAX        INT8_MAX
typedef uint8_t         ui8_t;
typedef int8_t          si8_t;
#elif UCHAR_MAX != 255
# error UCHAR_MAX must be 255
#else
# define UI8_MAX        UCHAR_MAX
# define SI8_MIN        CHAR_MIN
# define SI8_MAX        CHAR_MAX
typedef unsigned char   ui8_t;
typedef signed char     si8_t;
#endif

#if !defined PRIu8 || !defined PRId8
# undef PRIu8
# undef PRId8
# define PRIu8          "hhu"
# define PRId8          "hhd"
#endif

#ifdef UINT16_MAX
# define UI16_MAX       UINT16_MAX
# define SI16_MIN       INT16_MIN
# define SI16_MAX       INT16_MAX
typedef uint16_t        ui16_t;
typedef int16_t         si16_t;
#elif USHRT_MAX != 0xFFFFu
# error USHRT_MAX must be 0xFFFF
#else
# define UI16_MAX       USHRT_MAX
# define SI16_MIN       SHRT_MIN
# define SI16_MAX       SHRT_MAX
typedef unsigned short  ui16_t;
typedef signed short    si16_t;
#endif

#if !defined PRIu16 || !defined PRId16
# undef PRIu16
# undef PRId16
# if UI16_MAX == UINT_MAX
#  define PRIu16        "u"
#  define PRId16        "d"
# else
#  define PRIu16        "hu"
#  define PRId16        "hd"
# endif
#endif

#ifdef UINT32_MAX
# define UI32_MAX       UINT32_MAX
# define SI32_MIN       INT32_MIN
# define SI32_MAX       INT32_MAX
typedef uint32_t        ui32_t;
typedef int32_t         si32_t;
#elif ULONG_MAX == 0xFFFFFFFFu
# define UI32_MAX       ULONG_MAX
# define SI32_MIN       LONG_MIN
# define SI32_MAX       LONG_MAX
typedef unsigned long int  ui32_t;
typedef signed long int    si32_t;
#elif UINT_MAX != 0xFFFFFFFFu
# error UINT_MAX must be 0xFFFFFFFF
#else
# define UI32_MAX       UINT_MAX
# define SI32_MIN       INT_MIN
# define SI32_MAX       INT_MAX
typedef unsigned int    ui32_t;
typedef signed int      si32_t;
#endif

#if !defined PRIu32 || !defined PRId32
# undef PRIu32
# undef PRId32
# if UI32_MAX == ULONG_MAX
#  define PRIu32        "lu"
#  define PRId32        "ld"
# else
#  define PRIu32        "u"
#  define PRId32        "d"
# endif
#endif

#ifdef UINT64_MAX
# define UI64_MAX       UINT64_MAX
# define SI64_MIN       INT64_MIN
# define SI64_MAX       INT64_MAX
typedef uint64_t        ui64_t;
typedef int64_t         si64_t;
#elif ULONG_MAX <= 0xFFFFFFFFu
# if !defined ULLONG_MAX || (ULLONG_MAX >> 31) < 0xFFFFFFFFu
#  error We need a 64 bit integer
# else
#  define UI64_MAX      ULLONG_MAX
#  define SI64_MIN      LLONG_MIN
#  define SI64_MAX      LLONG_MAX
__EXTEN typedef unsigned long long  ui64_t;
__EXTEN typedef signed long long    si64_t;
# endif
#else
# define UI64_MAX       ULONG_MAX
# define SI64_MIN       LONG_MIN
# define SI64_MAX       LONG_MAX
typedef unsigned long   ui64_t;
typedef signed long     si64_t;
#endif

/* PRIo64 for `vexpr' */
#if !defined PRIu64 || !defined PRId64 || !defined PRIX64 || !defined PRIo64
# undef PRIu64
# undef PRId64
# undef PRIX64
# undef PRIo64
# if defined ULLONG_MAX && UI64_MAX == ULLONG_MAX
#  define PRIu64        "llu"
#  define PRId64        "lld"
#  define PRIX64        "llX"
#  define PRIo64        "llo"
# else
#  define PRIu64        "lu"
#  define PRId64        "ld"
#  define PRIX64        "lX"
#  define PRIo64        "lo"
# endif
#endif

/* (So that we can use UICMP() for size_t comparison, too) */
typedef size_t          uiz_t;
typedef ssize_t         siz_t;

#undef PRIuZ
#undef PRIdZ
#if defined __STDC_VERSION__ && __STDC_VERSION__ + 0 >= 199901L
# define PRIuZ          "zu"
# define PRIdZ          "zd"
# define UIZ_MAX        SIZE_MAX
#elif defined SIZE_MAX
  /* UnixWare has size_t as unsigned as required but uses a signed limit
   * constant (which is thus false!) */
# if SIZE_MAX == UI64_MAX || SIZE_MAX == SI64_MAX
#  define PRIuZ         PRIu64
#  define PRIdZ         PRId64
n_MCTA(sizeof(size_t) == sizeof(ui64_t),
   "Format string mismatch, compile with ISO C99 compiler (-std=c99)!")
# elif SIZE_MAX == UI32_MAX || SIZE_MAX == SI32_MAX
#  define PRIuZ         PRIu32
#  define PRIdZ         PRId32
n_MCTA(sizeof(size_t) == sizeof(ui32_t),
   "Format string mismatch, compile with ISO C99 compiler (-std=c99)!")
# else
#  error SIZE_MAX is neither UI64_MAX nor UI32_MAX (please report this)
# endif
# define UIZ_MAX        SIZE_MAX
#endif
#ifndef PRIuZ
# define PRIuZ          "lu"
# define PRIdZ          "ld"
n_MCTA(sizeof(size_t) == sizeof(unsigned long),
   "Format string mismatch, compile with ISO C99 compiler (-std=c99)!")
# define UIZ_MAX        ULONG_MAX
#endif

#ifndef UINTPTR_MAX
# ifdef SIZE_MAX
#  define uintptr_t     size_t
# else
#  define uintptr_t     unsigned long
# endif
#endif

#ifdef HAVE_C90AMEND1
typedef wchar_t         wc_t;
# define n_WC_C(X)      L ## X
#else
typedef char            wc_t; /* Yep: really 8-bit char */
# define n_WC_C(X)      X
#endif

enum {FAL0, TRU1, TRUM1 = -1};
typedef si8_t           bool_t;

/* Add shorter aliases for "normal" integers TODO v15 -> n_XX_t */
typedef unsigned long   ul_i;
typedef unsigned int    ui_i;
typedef unsigned short  us_i;
typedef unsigned char   uc_i;

typedef signed long     sl_i;
typedef signed int      si_i;
typedef signed short    ss_i;
typedef signed char     sc_i;

typedef void (          *sighandler_type)(int); /* TODO v15 obsolete */
typedef void (          *n_sighdl_t)(int);

enum n_announce_flags{
   n_ANNOUNCE_NONE = 0,          /* Only housekeeping */
   n_ANNOUNCE_MAIN_CALL = 1u<<0, /* POSIX covered startup call */
   n_ANNOUNCE_STATUS = 1u<<1,    /* Only print status */
   n_ANNOUNCE_CHANGE = 1u<<2,    /* Folder changed */

   n__ANNOUNCE_HEADER = 1u<<6,
   n__ANNOUNCE_ANY = 1u<<7
};

enum authtype {
   AUTHTYPE_NONE     = 1<<0,
   AUTHTYPE_PLAIN    = 1<<1,  /* POP3: APOP is covered by this */
   AUTHTYPE_LOGIN    = 1<<2,
   AUTHTYPE_CRAM_MD5 = 1<<3,
   AUTHTYPE_GSSAPI   = 1<<4
};

enum expand_addr_flags {
   EAF_NONE       = 0,        /* -> EAF_NOFILE | EAF_NOPIPE */
   EAF_RESTRICT   = 1<<0,     /* "restrict" (do unless interaktive / -[~#]) */
   EAF_FAIL       = 1<<1,     /* "fail" */
   EAF_FAILINVADDR = 1<<2,    /* "failinvaddr" */
   /* TODO HACK!  In pre-v15 we have a control flow problem (it is a general
    * TODO design problem): if collect() calls makeheader(), e.g., for -t or
    * TODO because of ~e diting, then that will checkaddr() and that will
    * TODO remove invalid headers.  However, this code path does not know
    * TODO about keeping track of senderrors unless a pointer has been passed,
    * TODO but which it doesn't for ~e, and shall not, too.  Thus, invalid
    * TODO addresses may be automatically removed, silently, and noone will
    * TODO ever know, in particular not regarding "failinvaddr".
    * TODO The hacky solution is this bit -- which can ONLY be used for fields
    * TODO which will be subject to namelist_vaporise_head() later on!! --,
    * TODO if it is set (by extract_header()) then checkaddr() will NOT strip
    * TODO invalid headers off IF it deals with a NULL senderror pointer */
   EAF_MAYKEEP    = 1<<3,
   /* Bits reused by enum expand_addr_check_mode! */
   EAF_FILE       = 1<<4,     /* +"file" targets */
   EAF_PIPE       = 1<<5,     /* +"pipe" command pipe targets */
   EAF_NAME       = 1<<6,     /* +"name"s (non-address) names / MTA aliases */
   EAF_ADDR       = 1<<7,     /* +"addr" network address (contain "@") */

   EAF_TARGET_MASK  = EAF_FILE | EAF_PIPE | EAF_NAME | EAF_ADDR,
   EAF_RESTRICT_TARGETS = EAF_NAME | EAF_ADDR /* (default set if not set) */
};

enum expand_addr_check_mode {
   EACM_NONE      = 0,        /* Don't care about *expandaddr* */
   EACM_NORMAL    = 1<<0,     /* Use our normal *expandaddr* checking */
   EACM_STRICT    = 1<<1,     /* Never allow any file or pipe addresse */
   EACM_MODE_MASK = 0x3,      /* _NORMAL and _STRICT are mutual! */

   EACM_NOLOG     = 1<<2,     /* Don't log check errors */

   /* Some special overwrites of EAF_TARGETs.
    * May NOT clash with EAF_* bits which may be ORd to these here! */

   EACM_NONAME    = 1<<16
};

enum n_cmd_arg_flags{ /* TODO Most of these need to change, in fact in v15
   * TODO i rather see the mechanism that is used in c_bind() extended and used
   * TODO anywhere, i.e. n_cmd_arg_parse().
   * TODO Note that we may NOT support arguments with strlen()>=UI32_MAX (?) */
   n_CMD_ARG_TYPE_MSGLIST = 0,   /* Message list type */
   n_CMD_ARG_TYPE_NDMLIST = 1,   /* Message list, no defaults */
   n_CMD_ARG_TYPE_RAWDAT = 2,    /* The plain string in an argv[] */
     n_CMD_ARG_TYPE_STRING = 3,  /* A pure string TODO obsolete */
   n_CMD_ARG_TYPE_WYSH = 4,      /* getrawlist(), sh(1) compatible */
      n_CMD_ARG_TYPE_RAWLIST = 5, /* getrawlist(), old style TODO obsolete */
     n_CMD_ARG_TYPE_WYRA = 6,    /* _RAWLIST or _WYSH (with `wysh') TODO obs. */
   n_CMD_ARG_TYPE_ARG = 7,       /* n_cmd_arg_desc/n_cmd_arg() new-style */
   n_CMD_ARG_TYPE_MASK = 7,      /* Mask of the above */

   n_CMD_ARG_A = 1u<<4,    /* Needs an active mailbox */
   n_CMD_ARG_F = 1u<<5,    /* Is a conditional command */
   n_CMD_ARG_G = 1u<<6,    /* Is supposed to produce "gabby" history */
   n_CMD_ARG_H = 1u<<7,    /* Never place in `history' */
   n_CMD_ARG_I = 1u<<8,    /* Interactive command bit */
   n_CMD_ARG_L = 1u<<9,    /* Supports `local' prefix (only WYSH/WYRA) */
   n_CMD_ARG_M = 1u<<10,   /* Legal from send mode bit */
   n_CMD_ARG_O = 1u<<11,   /* n_OBSOLETE()d command */
   n_CMD_ARG_P = 1u<<12,   /* Autoprint dot after command */
   n_CMD_ARG_R = 1u<<13,   /* Forbidden in compose mode recursion */
   n_CMD_ARG_SC = 1u<<14,  /* Forbidden pre-n_PSO_STARTED_CONFIG */
   n_CMD_ARG_S = 1u<<15,   /* Forbidden pre-n_PSO_STARTED (POSIX) */
   n_CMD_ARG_T = 1u<<16,   /* Is a transparent command */
   n_CMD_ARG_V = 1u<<17,   /* Supports `vput' prefix (only WYSH/WYRA) */
   n_CMD_ARG_W = 1u<<18,   /* Invalid when read only bit */
   n_CMD_ARG_X = 1u<<19,   /* Valid command in n_PS_COMPOSE_FORKHOOK mode */
   /* XXX Note that CMD_ARG_EM implies a _real_ return value for $! */
   n_CMD_ARG_EM = 1u<<30   /* If error: n_pstate_err_no (4 $! aka. ok_v___em) */
};

enum n_cmd_arg_desc_flags{/* TODO incomplete, misses getmsglist() */
   /* - A type */
   n_CMD_ARG_DESC_STRING = 1u<<0,   /* A !blankspacechar() string */
   n_CMD_ARG_DESC_WYSH = 1u<<1,     /* sh(1)ell-style quoted */

   n__CMD_ARG_DESC_TYPE_MASK = n_CMD_ARG_DESC_STRING | n_CMD_ARG_DESC_WYSH,

   /* - Optional flags */
   /* It is not an error if an optional argument is missing; once an argument
    * has been declared optional only optional arguments may follow */
   n_CMD_ARG_DESC_OPTION = 1u<<16,
   /* GREEDY: parse as many of that type as possible; must be last entry */
   n_CMD_ARG_DESC_GREEDY = 1u<<17,
   /* If greedy, join all given arguments separated by ASCII SP right away */
   n_CMD_ARG_DESC_GREEDY_JOIN = 1u<<18,
   /* Honour an overall "stop" request in one of the arguments (\c@ or #) */
   n_CMD_ARG_DESC_HONOUR_STOP = 1u<<19,

   n__CMD_ARG_DESC_FLAG_MASK = n_CMD_ARG_DESC_OPTION | n_CMD_ARG_DESC_GREEDY |
         n_CMD_ARG_DESC_GREEDY_JOIN | n_CMD_ARG_DESC_HONOUR_STOP
};

#ifdef HAVE_COLOUR
/* We do have several contexts of colour IDs; since only one of them can be
 * active at any given time let's share the value range */
enum n_colour_ctx{
   n_COLOUR_CTX_SUM,
   n_COLOUR_CTX_VIEW,
   n_COLOUR_CTX_MLE,
   n__COLOUR_CTX_MAX1
};

enum n_colour_id{
   /* Header summary */
   n_COLOUR_ID_SUM_DOTMARK = 0,
   n_COLOUR_ID_SUM_HEADER,
   n_COLOUR_ID_SUM_THREAD,

   /* Message display */
   n_COLOUR_ID_VIEW_FROM_ = 0,
   n_COLOUR_ID_VIEW_HEADER,
   n_COLOUR_ID_VIEW_MSGINFO,
   n_COLOUR_ID_VIEW_PARTINFO,

   /* Mailx-Line-Editor */
   n_COLOUR_ID_MLE_POSITION = 0,
   n_COLOUR_ID_MLE_PROMPT,

   n__COLOUR_IDS = n_COLOUR_ID_VIEW_PARTINFO + 1
};

/* Colour preconditions, let's call them tags, cannot be an enum because for
 * message display they are the actual header name of the current header.  Thus
 * let's use constants of pseudo pointers */
# define n_COLOUR_TAG_SUM_DOT ((char*)-2)
# define n_COLOUR_TAG_SUM_OLDER ((char*)-3)
#endif /* HAVE_COLOUR */

enum conversion {
   CONV_NONE,        /* no conversion */
   CONV_7BIT,        /* no conversion, is 7bit */
   CONV_FROMQP,      /* convert from quoted-printable */
   CONV_TOQP,        /* convert to quoted-printable */
   CONV_8BIT,        /* convert to 8bit (iconv) */
   CONV_FROMB64,     /* convert from base64 */
   CONV_FROMB64_T,   /* convert from base64/text */
   CONV_TOB64,       /* convert to base64 */
   CONV_FROMHDR,     /* convert from RFC1522 format */
   CONV_TOHDR,       /* convert to RFC1522 format */
   CONV_TOHDR_A      /* convert addresses for header */
};

enum cproto {
   CPROTO_CCRED,     /* Special dummy credential proto (S/MIME etc.) */
   CPROTO_SOCKS,     /* Special dummy SOCKS5 proxy proto */
   CPROTO_SMTP,
   CPROTO_POP3
,CPROTO_IMAP
};

enum n_dotlock_state{
   n_DLS_NONE,
   n_DLS_CANT_CHDIR,    /* Failed to chdir(2) into desired path */
   n_DLS_NAMETOOLONG,   /* Lock file name would be too long */
   n_DLS_ROFS,          /* Read-only filesystem (no error, mailbox RO) */
   n_DLS_NOPERM,        /* No permission to creat lock file */
   n_DLS_NOEXEC,        /* Privilege separated dotlocker not found */
   n_DLS_PRIVFAILED,    /* Rising privileges failed in dotlocker */
   n_DLS_EXIST,         /* Lock file already exists, stale lock? */
   n_DLS_FISHY,         /* Something makes us think bad of situation */
   n_DLS_DUNNO,         /* Catch-all error */
   n_DLS_PING,          /* Not an error, but have to wait for lock */
   n_DLS_ABANDON = 1<<7 /* ORd to any but _NONE: give up, don't retry */
};

/* enum n_err_number from mk-config.h, which is in sync with
 * n_err_to_doc(), n_err_to_name() and n_err_from_name() */

enum n_exit_status{
   n_EXIT_OK = EXIT_SUCCESS,
   n_EXIT_ERR = EXIT_FAILURE,
   n_EXIT_USE = 64,           /* sysexits.h:EX_USAGE */
   n_EXIT_NOUSER = 67,        /* :EX_NOUSER */
   n_EXIT_COLL_ABORT = 1<<1,  /* Message collection was aborted */
   n_EXIT_SEND_ERROR = 1<<2   /* Unspecified send error occurred */
};

enum fedit_mode {
   FEDIT_NONE     = 0,
   FEDIT_SYSBOX   = 1<<0,     /* %: prefix */
   FEDIT_RDONLY   = 1<<1,     /* Readonly (per-box, n_OPT_R_FLAG is global) */
   FEDIT_NEWMAIL  = 1<<2      /* `newmail' operation TODO OBSOLETE THIS! */
};

enum fexp_mode {
   FEXP_FULL,                 /* Full expansion */
   FEXP_NOPROTO = 1<<0,       /* TODO no which_protocol() to decide expansion */
   FEXP_SILENT = 1<<1,        /* Don't print but only return errors */
   FEXP_MULTIOK = 1<<2,       /* Expansion to many entries is ok */
   FEXP_LOCAL = 1<<3,         /* Result must be local file/maildir */
   FEXP_NSHORTCUT = 1<<4,     /* Don't expand shortcuts */
   FEXP_NSPECIAL = 1<<5,      /* No %,#,& specials */
   FEXP_NFOLDER = 1<<6,       /* NSPECIAL and no + folder, too */
   FEXP_NSHELL = 1<<7,        /* Don't do shell word exp. (but ~/, $VAR) */
   FEXP_NVAR = 1<<8           /* ..not even $VAR expansion */
};

enum n_file_lock_type{
   FLT_READ,
   FLT_WRITE
};

enum n_fopen_state{ /* TODO add n_fopen_mode, too */
   /* First n__PROTO_SHIFT bits are enum protocol!  n_MCTA()d below */
   n_FOPEN_STATE_NONE = 0,
   n_FOPEN_STATE_EXISTS = 1u<<5
};

enum n_go_input_flags{
   n_GO_INPUT_NONE,
   n_GO_INPUT_CTX_BASE = 0,            /* Generic shared base: don't use! */
   n_GO_INPUT_CTX_DEFAULT = 1,         /* Default input */
   n_GO_INPUT_CTX_COMPOSE = 2,         /* Compose mode input */
   n__GO_INPUT_CTX_MASK = 3,
   n__GO_INPUT_CTX_MAX1 = n_GO_INPUT_CTX_COMPOSE + 1,

   n_GO_INPUT_HOLDALLSIGS = 1u<<8,     /* hold_all_sigs() active TODO */
   /* `xcall' is `call' (at the level where this is set): to be set when
    * teardown of top level has undesired effects, e.g., for `account's and
    * folder hooks etc., where we do not to loose our `localopts' unroll list */
   n_GO_INPUT_NO_XCALL = 1u<<9,

   n_GO_INPUT_FORCE_STDIN = 1u<<10,    /* Even in macro, use stdin (`read')! */
   n_GO_INPUT_NL_ESC = 1u<<11,         /* Support "\\$" line continuation */
   n_GO_INPUT_NL_FOLLOW = 1u<<12,      /* ..on such a follow line */
   n_GO_INPUT_PROMPT_NONE = 1u<<13,    /* Don't print prompt */
   n_GO_INPUT_PROMPT_EVAL = 1u<<14,    /* Instead, evaluate *prompt* */

   n_GO_INPUT_HIST_ADD = 1u<<16,       /* Add the result to history list */
   n_GO_INPUT_HIST_GABBY = 1u<<17,     /* Consider history entry as gabby */

   n__GO_FREEBIT = 24
};

enum n_go_input_inject_flags{
   n_GO_INPUT_INJECT_NONE = 0,
   n_GO_INPUT_INJECT_COMMIT = 1u<<0,   /* Auto-commit input */
   n_GO_INPUT_INJECT_HISTORY = 1u<<1   /* Allow history addition */
};

enum n_iconv_flags{
   n_ICONV_NONE = 0,
   n_ICONV_IGN_ILSEQ = 1<<0,     /* Ignore EILSEQ in input (replacement char) */
   n_ICONV_IGN_NOREVERSE = 1<<1, /* .. non-reversible conversions in output */
   n_ICONV_UNIREPL = 1<<2,       /* Use Unicode replacement 0xFFFD = EF BF BD */
   n_ICONV_DEFAULT = n_ICONV_IGN_ILSEQ | n_ICONV_IGN_NOREVERSE,
   n_ICONV_UNIDEFAULT = n_ICONV_DEFAULT | n_ICONV_UNIREPL
};

/* Special ignore (where _TYPE is covered by POSIX `ignore' / `retain').
 * _ALL is very special in that it doesn't have a backing object.
 * Go over enum to avoid cascads of (different) CC warnings for used CTA()s */
#define n_IGNORE_ALL ((struct n_ignore*)n__IGNORE_ALL)
#define n_IGNORE_TYPE ((struct n_ignore*)n__IGNORE_TYPE)
#define n_IGNORE_SAVE ((struct n_ignore*)n__IGNORE_SAVE)
#define n_IGNORE_FWD ((struct n_ignore*)n__IGNORE_FWD)
#define n_IGNORE_TOP ((struct n_ignore*)n__IGNORE_TOP)

enum{
   n__IGNORE_ALL = -2,
   n__IGNORE_TYPE = -3,
   n__IGNORE_SAVE = -4,
   n__IGNORE_FWD = -5,
   n__IGNORE_TOP = -6,
   n__IGNORE_ADJUST = 3,
   n__IGNORE_MAX = 6 - n__IGNORE_ADJUST
};

enum n_idec_mode{
   n_IDEC_MODE_NONE,
   n_IDEC_MODE_SIGNED_TYPE = 1u<<0, /* To choose limits, error constants etc. */
#if 0
   n_IDEC_MODE_SIGN_FORCE_SIGNED_TYPE = 1u<<2,
#endif
   n_IDEC_MODE_LIMIT_8BIT = 1u<<3,  /* Saturate if result exceeds 8-bit */
   n_IDEC_MODE_LIMIT_16BIT = 2u<<3,
   n_IDEC_MODE_LIMIT_32BIT = 3u<<3,
   n__IDEC_MODE_LIMIT_MASK = 3u<<3,
   n_IDEC_MODE_LIMIT_NOERROR = 1u<<5, /* Not an error if limit is excessed! */
   /* These bits are duplicated in the _state result bits! */
   n__IDEC_MODE_MASK = (1u<<6) - 1
};

enum n_idec_state{
   n_IDEC_STATE_NONE,
   /* Malformed input, no usable result has been stored */
   n_IDEC_STATE_EINVAL = 1u<<8,
   /* Bad character according to base, but we have seen some good before,
    * otherwise _EINVAL would have been used */
   n_IDEC_STATE_EBASE = 2u<<8,
   n_IDEC_STATE_EOVERFLOW = 3u<<8,  /* Result too large */
   n_IDEC_STATE_EMASK = 3u<<8,      /* Any errors, that is */
   n_IDEC_STATE_SEEN_MINUS = 1u<<16, /* Seen - in input? */
   n_IDEC_STATE_CONSUMED = 1u<<17,  /* All the input buffer was consumed */
   n__IDEC_PRIVATE_SHIFT1 = 24u
};
n_MCTA(n__IDEC_MODE_MASK <= (1u<<8) - 1, "Shared bit range overlaps")

enum mimecontent {
   MIME_UNKNOWN,     /* unknown content */
   MIME_SUBHDR,      /* inside a multipart subheader */
   MIME_822,         /* message/rfc822 content */
   MIME_MESSAGE,     /* other message/ content */
   MIME_TEXT_PLAIN,  /* text/plain content */
   MIME_TEXT_HTML,   /* text/html content */
   MIME_TEXT,        /* other text/ content */
   MIME_ALTERNATIVE, /* multipart/alternative content */
   MIME_RELATED,     /* mime/related (RFC 2387) */
   MIME_DIGEST,      /* multipart/digest content */
   MIME_SIGNED,      /* multipart/signed */
   MIME_ENCRYPTED,   /* multipart/encrypted */
   MIME_MULTI,       /* other multipart/ content */
   MIME_PKCS7,       /* PKCS7 content */
   MIME_DISCARD      /* content is discarded */
};

enum mime_counter_evidence {
   MIMECE_NONE,
   MIMECE_SET        = 1<<0,  /* *mime-counter-evidence* was set */
   MIMECE_BIN_OVWR   = 1<<1,  /* appli../octet-stream: check, ovw if possible */
   MIMECE_ALL_OVWR   = 1<<2,  /* all: check, ovw if possible */
   MIMECE_BIN_PARSE  = 1<<3   /* appli../octet-stream: classify contents last */
};

/* Content-Transfer-Encodings as defined in RFC 2045:
 * - Quoted-Printable, section 6.7
 * - Base64, section 6.8 */
#define QP_LINESIZE     (4 * 19)       /* Max. compliant QP linesize */

#define B64_LINESIZE    (4 * 19)       /* Max. compliant Base64 linesize */
#define B64_ENCODE_INPUT_PER_LINE ((B64_LINESIZE / 4) * 3)

enum mime_enc {
   MIMEE_NONE,       /* message is not in MIME format */
   MIMEE_BIN,        /* message is in binary encoding */
   MIMEE_8B,         /* message is in 8bit encoding */
   MIMEE_7B,         /* message is in 7bit encoding */
   MIMEE_QP,         /* message is quoted-printable */
   MIMEE_B64         /* message is in base64 encoding */
};

/* xxx QP came later, maybe rewrite all to use mime_enc_flags directly? */
enum mime_enc_flags {
   MIMEEF_NONE,
   MIMEEF_SALLOC     = 1<<0,  /* Use salloc(), not srealloc().. */
   /* ..result .s,.l point to user buffer of *_LINESIZE+[+[+]] bytes instead */
   MIMEEF_BUF        = 1<<1,
   MIMEEF_CRLF       = 1<<2,  /* (encode) Append "\r\n" to lines */
   MIMEEF_LF         = 1<<3,  /* (encode) Append "\n" to lines */
   /* (encode) If one of _CRLF/_LF is set, honour *_LINESIZE+[+[+]] and
    * inject the desired line-ending whenever a linewrap is desired */
   MIMEEF_MULTILINE  = 1<<4,
   /* (encode) Quote with header rules, do not generate soft NL breaks?
    * For mustquote(), specifies whether special RFC 2047 header rules
    * should be used instead */
   MIMEEF_ISHEAD     = 1<<5,
   /* (encode) Ditto; for mustquote() this furtherly fine-tunes behaviour in
    * that characters which would not be reported as "must-quote" when
    * detecting whether quoting is necessary at all will be reported as
    * "must-quote" if they have to be encoded in an encoded word */
   MIMEEF_ISENCWORD  = 1<<6,
   __MIMEEF_LAST     = 6
};

enum qpflags {
   QP_NONE        = MIMEEF_NONE,
   QP_SALLOC      = MIMEEF_SALLOC,
   QP_BUF         = MIMEEF_BUF,
   QP_ISHEAD      = MIMEEF_ISHEAD,
   QP_ISENCWORD   = MIMEEF_ISENCWORD
};

enum b64flags {
   B64_NONE       = MIMEEF_NONE,
   B64_SALLOC     = MIMEEF_SALLOC,
   B64_BUF        = MIMEEF_BUF,
   B64_CRLF       = MIMEEF_CRLF,
   B64_LF         = MIMEEF_LF,
   B64_MULTILINE  = MIMEEF_MULTILINE,
   /* Not used, but for clarity only */
   B64_ISHEAD     = MIMEEF_ISHEAD,
   B64_ISENCWORD  = MIMEEF_ISENCWORD,
   /* Special version of Base64, "Base64URL", according to RFC 4648.
    * Only supported for encoding! */
   B64_RFC4648URL = 1<<(__MIMEEF_LAST+1),
   /* Don't use any ("=") padding;
    * may NOT be used with any of _CRLF, _LF or _MULTILINE */
   B64_NOPAD      = 1<<(__MIMEEF_LAST+2)
};

enum mime_parse_flags {
   MIME_PARSE_NONE,
   MIME_PARSE_DECRYPT = 1u<<0,
   MIME_PARSE_PARTS = 1u<<1,
   MIME_PARSE_SHALLOW = 1u<<2,
   /* In effect we parse this message for user display or quoting purposes, so
    * relaxed rules regarding content inspection may be applicable */
   MIME_PARSE_FOR_USER_CONTEXT = 1u<<3
};

enum mime_handler_flags {
   MIME_HDL_NULL,                /* No pipe- mimetype handler, go away */
   MIME_HDL_CMD,                 /* Normal command */
   MIME_HDL_TEXT,                /* @ special cmd to force treatment as text */
   MIME_HDL_PTF,                 /* A special pointer-to-function handler */
   MIME_HDL_MSG,                 /* Display msg (returned as command string) */
   MIME_HDL_TYPE_MASK = 7u,
   MIME_HDL_COPIOUSOUTPUT = 1u<<4, /* _CMD produces reintegratable text */
   MIME_HDL_ISQUOTE = 1u<<5,     /* Is quote action (we have info, keep it!) */
   MIME_HDL_NOQUOTE = 1u<<6,     /* No MIME for quoting */
   MIME_HDL_ASYNC = 1u<<7,       /* Should run asynchronously */
   MIME_HDL_NEEDSTERM = 1u<<8,   /* Takes over terminal */
   MIME_HDL_TMPF = 1u<<9,        /* Create temporary file (zero-sized) */
   MIME_HDL_TMPF_FILL = 1u<<10,  /* Fill in the msg body content */
   MIME_HDL_TMPF_UNLINK = 1u<<11 /* Delete it later again */
};

enum mlist_state {
   MLIST_OTHER       = 0,     /* Normal address */
   MLIST_KNOWN       = 1,     /* A known `mlist' */
   MLIST_SUBSCRIBED  = -1     /* A `mlsubscribe'd list */
};

enum oflags {
   OF_RDONLY      = 1<<0,
   OF_WRONLY      = 1<<1,
   OF_RDWR        = 1<<2,
   OF_APPEND      = 1<<3,
   OF_CREATE      = 1<<4,
   OF_TRUNC       = 1<<5,
   OF_EXCL        = 1<<6,
   OF_CLOEXEC     = 1<<7,     /* TODO not used, always implied!  CHANGE!! */
   OF_UNLINK      = 1<<8,     /* Only for Ftmp(): unlink(2) after creation */
   OF_HOLDSIGS    = 1<<9,     /* Mutual with OF_UNLINK - await Ftmp_free() */
   OF_REGISTER    = 1<<10,    /* Register file in our file table */
   OF_REGISTER_UNLINK = 1<<11, /* unlink(2) upon unreg.; _REGISTER asserted! */
   OF_SUFFIX      = 1<<12     /* Ftmp() name hint is mandatory! extension! */
};

enum okay {
   STOP = 0,
   OKAY = 1
};

enum okey_xlook_mode {
   OXM_PLAIN      = 1<<0,     /* Plain key always tested */
   OXM_H_P        = 1<<1,     /* Check PLAIN-.url_h_p */
   OXM_U_H_P      = 1<<2,     /* Check PLAIN-.url_u_h_p */
   OXM_ALL        = 0x7
};

/* <0 means "stop" unless *prompt* extensions are enabled. */
enum prompt_exp {
   PROMPT_STOP    = -1,       /* \c */
   /* *prompt* extensions: \$, \@ etc. */
   PROMPT_DOLLAR  = -2,
   PROMPT_AT      = -3
};

enum protocol {
   n_PROTO_NONE,
   n_PROTO_FILE,        /* refers to a local file */
PROTO_FILE = n_PROTO_FILE,
   n_PROTO_POP3,        /* is a pop3 server string */
PROTO_POP3 = n_PROTO_POP3,
n_PROTO_IMAP,
PROTO_IMAP = n_PROTO_IMAP,
   n_PROTO_MAILDIR,     /* refers to a maildir folder */
PROTO_MAILDIR = n_PROTO_MAILDIR,
   n_PROTO_UNKNOWN,     /* unknown protocol */
PROTO_UNKNOWN = n_PROTO_UNKNOWN,

   n__PROTO_SHIFT = n_PROTO_UNKNOWN,
   n_PROTO_MASK = (1u << n__PROTO_SHIFT) - 1
};
n_MCTA(n__PROTO_SHIFT == 5, "enum n_fopen_state shift value must be adjusted!")

enum sendaction {
   SEND_MBOX,        /* no conversion to perform */
   SEND_RFC822,      /* no conversion, no From_ line */
   SEND_TODISP,      /* convert to displayable form */
   SEND_TODISP_ALL,  /* same, include all MIME parts */
   SEND_TODISP_PARTS, /* same, but only interactive, user-selected parts */
   SEND_SHOW,        /* convert to 'show' command form */
   SEND_TOSRCH,      /* convert for IMAP SEARCH */
   SEND_TOFILE,      /* convert for saving body to a file */
   SEND_TOPIPE,      /* convert for pipe-content/subc. */
   SEND_QUOTE,       /* convert for quoting */
   SEND_QUOTE_ALL,   /* same, include all MIME parts */
   SEND_DECRYPT      /* decrypt */
};

enum n_shexp_parse_flags{
   n_SHEXP_PARSE_NONE,
   /* Don't perform expansions or interpret reverse solidus escape sequences.
    * Output may be NULL, otherwise the possibly trimmed non-expanded input is
    * used as output (implies _PARSE_META_KEEP) */
   n_SHEXP_PARSE_DRYRUN = 1u<<0,
   n_SHEXP_PARSE_TRUNC = 1u<<1,        /* Truncate result storage on entry */
   n_SHEXP_PARSE_TRIM_SPACE = 1u<<2,   /* ..surrounding tokens */
   n_SHEXP_PARSE_TRIM_IFSSPACE = 1u<<3, /* " */
   n_SHEXP_PARSE_LOG = 1u<<4,          /* Log errors */
   n_SHEXP_PARSE_LOG_D_V = 1u<<5,      /* Log errors if n_PO_D_V */
   n_SHEXP_PARSE_IFS_VAR = 1u<<6,      /* IFS is *ifs*, not blankchar() */
   n_SHEXP_PARSE_IFS_ADD_COMMA = 1u<<7, /* Add comma , to normal "IFS" */
   n_SHEXP_PARSE_IFS_IS_COMMA = 1u<<8, /* Let comma , be the sole "IFS" */
   n_SHEXP_PARSE_IGNORE_EMPTY = 1u<<9, /* Ignore empty tokens, start over */

   /* Implicitly open quotes, and ditto closing.  _AUTO_FIXED may only be used
    * if an auto-quote-mode is enabled, implies _AUTO_CLOSE and causes the
    * quote mode to be permanently active (cannot be closed) */
   n_SHEXP_PARSE_QUOTE_AUTO_FIXED = 1u<<16,
   n_SHEXP_PARSE_QUOTE_AUTO_SQ = 1u<<17,
   n_SHEXP_PARSE_QUOTE_AUTO_DQ = 1u<<18,
   n_SHEXP_PARSE_QUOTE_AUTO_DSQ = 1u<<19,
   n_SHEXP_PARSE_QUOTE_AUTO_CLOSE = 1u<<20, /* Ignore an open quote at EOS */
   n__SHEXP_PARSE_QUOTE_AUTO_MASK = n_SHEXP_PARSE_QUOTE_AUTO_SQ |
         n_SHEXP_PARSE_QUOTE_AUTO_DQ | n_SHEXP_PARSE_QUOTE_AUTO_DSQ,

   /* Recognize metacharacters to separate tokens */
   n_SHEXP_PARSE_META_VERTBAR = 1u<<21,
   n_SHEXP_PARSE_META_AMPERSAND = 1u<<22,
   /* Interpret ; as a sequencing operator, go_input_inject() remainder */
   n_SHEXP_PARSE_META_SEMICOLON = 1u<<23,
   /* LPAREN, RPAREN, LESSTHAN, GREATERTHAN */

   n_SHEXP_PARSE_META_MASK = n_SHEXP_PARSE_META_VERTBAR |
         n_SHEXP_PARSE_META_AMPERSAND | n_SHEXP_PARSE_META_SEMICOLON,

   /* Keep the metacharacter (or IFS character), do not skip over it */
   n_SHEXP_PARSE_META_KEEP = 1u<<24,

   n__SHEXP_PARSE_LAST = 24
};

enum n_shexp_state{
   n_SHEXP_STATE_NONE,
   /* We have produced some output (or would have, with _PARSE_DRYRUN).
    * Note that empty quotes like '' produce no output but set this bit */
   n_SHEXP_STATE_OUTPUT = 1u<<0,
   /* Don't call the parser again (# comment seen; out of input).
    * Not (necessarily) mutual with _OUTPUT) */
   n_SHEXP_STATE_STOP = 1u<<1,
   n_SHEXP_STATE_UNICODE = 1u<<2,         /* \[Uu] used */
   n_SHEXP_STATE_CONTROL = 1u<<3,         /* Control characters seen */
   n_SHEXP_STATE_QUOTE = 1u<<4,           /* Any quotes seen */
   n_SHEXP_STATE_WS_LEAD = 1u<<5,         /* _TRIM_{IFS,}SPACE: seen.. */
   n_SHEXP_STATE_WS_TRAIL = 1u<<6,        /* .. leading / trailing WS */
   n_SHEXP_STATE_META_VERTBAR = 1u<<7,    /* Metacharacter | follows/ed */
   n_SHEXP_STATE_META_AMPERSAND = 1u<<8,  /* Metacharacter & follows/ed */
   n_SHEXP_STATE_META_SEMICOLON = 1u<<9,  /* Metacharacter ; follows/ed */

   n_SHEXP_STATE_META_MASK = n_SHEXP_STATE_META_VERTBAR |
         n_SHEXP_STATE_META_AMPERSAND | n_SHEXP_STATE_META_SEMICOLON,

   n_SHEXP_STATE_ERR_CONTROL = 1u<<16,    /* \c notation with invalid arg. */
   n_SHEXP_STATE_ERR_UNICODE = 1u<<17,    /* Valid \[Uu] and !n_PSO_UNICODE */
   n_SHEXP_STATE_ERR_NUMBER = 1u<<18,     /* Bad number (\[UuXx]) */
   n_SHEXP_STATE_ERR_IDENTIFIER = 1u<<19, /* Invalid identifier */
   n_SHEXP_STATE_ERR_BADSUB = 1u<<20,     /* Empty/bad ${}/[] substitution */
   n_SHEXP_STATE_ERR_GROUPOPEN = 1u<<21,  /* _QUOTEOPEN + no }/]/)/ 4 ${/[/( */
   n_SHEXP_STATE_ERR_QUOTEOPEN = 1u<<22,  /* Quote remains open at EOS */

   n_SHEXP_STATE_ERR_MASK = n_BITENUM_MASK(16, 22)
};

enum n_sigman_flags{
   n_SIGMAN_NONE = 0,
   n_SIGMAN_HUP = 1<<0,
   n_SIGMAN_INT = 1<<1,
   n_SIGMAN_QUIT = 1<<2,
   n_SIGMAN_TERM = 1<<3,
   n_SIGMAN_PIPE = 1<<4,

   n_SIGMAN_IGN_HUP = 1<<5,
   n_SIGMAN_IGN_INT = 1<<6,
   n_SIGMAN_IGN_QUIT = 1<<7,
   n_SIGMAN_IGN_TERM = 1<<8,

   n_SIGMAN_ALL = 0xFF,
   /* Mostly for _leave() reraise flags */
   n_SIGMAN_VIPSIGS = n_SIGMAN_HUP | n_SIGMAN_INT | n_SIGMAN_QUIT |
         n_SIGMAN_TERM,
   n_SIGMAN_NTTYOUT_PIPE = 1<<16,
   n_SIGMAN_VIPSIGS_NTTYOUT = n_SIGMAN_HUP | n_SIGMAN_INT | n_SIGMAN_QUIT |
         n_SIGMAN_TERM | n_SIGMAN_NTTYOUT_PIPE,

   n__SIGMAN_PING = 1<<17
};

#ifdef HAVE_SSL
enum ssl_verify_level {
   SSL_VERIFY_IGNORE,
   SSL_VERIFY_WARN,
   SSL_VERIFY_ASK,
   SSL_VERIFY_STRICT
};
#endif

enum n_str_trim_flags{
   n_STR_TRIM_FRONT = 1u<<0,
   n_STR_TRIM_END = 1u<<1,
   n_STR_TRIM_BOTH = n_STR_TRIM_FRONT | n_STR_TRIM_END
};

enum tdflags {
   TD_NONE,                   /* no display conversion */
   TD_ISPR        = 1<<0,     /* use isprint() checks */
   TD_ICONV       = 1<<1,     /* use iconv() */
   TD_DELCTRL     = 1<<2,     /* delete control characters */

   /*
    * NOTE: _TD_EOF and _TD_BUFCOPY may be ORd with enum conversion and
    * enum sendaction, and may thus NOT clash with their bit range!
    */
   _TD_EOF        = 1<<14,    /* EOF seen, last round! */
   _TD_BUFCOPY    = 1<<15     /* Buffer may be constant, copy it */
};

#ifdef n_HAVE_TCAP
enum n_termcap_captype{
   n_TERMCAP_CAPTYPE_NONE = 0,
   /* Internally we share the bitspace, so ensure no value ends up as 0 */
   n_TERMCAP_CAPTYPE_BOOL = 1,
   n_TERMCAP_CAPTYPE_NUMERIC,
   n_TERMCAP_CAPTYPE_STRING,
   n__TERMCAP_CAPTYPE_MAX1
};

/* Termcap commands; different to queries commands perform actions.
 * Commands are resolved upon init time, and are all termcap(5)-compatible,
 * therefore we use the short termcap(5) names.
 * Note this is parsed by make-tcap-map.pl, which expects the syntax
 * "CONSTANT, COMMENT" where COMMENT is "Capname/TCap-Code, TYPE[, FLAGS]",
 * and one of Capname and TCap-Code may be the string "-" meaning ENOENT;
 * a | vertical bar or end-of-comment ends processing; see termcap.c.
 * We may use the free-form part after | for the "Variable String" and notes on
 * necessary termcap_cmd() arguments; if those are in [] brackets they are not
 * regular but are only used when the command, i.e., its effect, is somehow
 * simulated / faked by a built-in fallback implementation.
 * Availability of built-in fallback indicated by leading @ (at-sign) */
enum n_termcap_cmd{
# ifdef HAVE_TERMCAP
   n_TERMCAP_CMD_te, /* rmcup/te, STRING | exit_ca_mode: -,- */
   n_TERMCAP_CMD_ti, /* smcup/ti, STRING | enter_ca_mode: -,- */

   n_TERMCAP_CMD_ks, /* smkx/ks, STRING | keypad_xmit: -,- */
   n_TERMCAP_CMD_ke, /* rmkx/ke, STRING | keypad_local: -,- */

   n_TERMCAP_CMD_cd, /* ed/cd, STRING | clr_eos: -,- */
   n_TERMCAP_CMD_cl, /* clear/cl, STRING | clear_screen(+home): -,- */
   n_TERMCAP_CMD_ho, /* home/ho, STRING | cursor_home: -,- */
# endif

# ifdef HAVE_MLE
   n_TERMCAP_CMD_ce, /* el/ce, STRING | @ clr_eol: [start-column],- */
   n_TERMCAP_CMD_ch, /* hpa/ch, STRING, IDX1 | column_address: column,- */
   n_TERMCAP_CMD_cr, /* cr/cr, STRING | @ carriage_return: -,- */
   n_TERMCAP_CMD_le, /* cub1/le, STRING, CNT | @ cursor_left: count,- */
   n_TERMCAP_CMD_nd, /* cuf1/nd, STRING, CNT | @ cursor_right: count,- */
# endif

   n__TERMCAP_CMD_MAX1,
   n__TERMCAP_CMD_MASK = (1<<24) - 1,

   /* Only perform command if ca-mode is used */
   n_TERMCAP_CMD_FLAG_CA_MODE = 1<<29,
   /* I/O should be flushed after command completed */
   n_TERMCAP_CMD_FLAG_FLUSH = 1<<30
};

/* Termcap queries; a query is a command that returns a struct n_termcap_value.
 * Queries are resolved once they are used first, and may not be termcap(5)-
 * compatible, therefore we use terminfo(5) names.
 * Note this is parsed by make-tcap-map.pl, which expects the syntax
 * "CONSTANT, COMMENT" where COMMENT is "Capname/TCap-Code, TYPE[, FLAGS]",
 * and one of Capname and TCap-Code may be the string "-" meaning ENOENT;
 * a | vertical bar or end-of-comment ends processing; see termcap.c.
 * We may use the free-form part after | for the "Variable String" and notes.
 * The "xkey | X:" keys are Dickey's xterm extensions, see (our) manual */
enum n_termcap_query{
# ifdef HAVE_COLOUR
   n_TERMCAP_QUERY_colors, /* colors/Co, NUMERIC | max_colors */
# endif

   /* --make-tcap-map--: only KEY_BINDINGS follow.  DON'T CHANGE THIS LINE! */
   /* Update the `bind' manual on change! */
# ifdef HAVE_KEY_BINDINGS
   n_TERMCAP_QUERY_key_backspace, /* kbs/kb, STRING */
   n_TERMCAP_QUERY_key_dc,       /* kdch1/kD, STRING | delete-character */
      n_TERMCAP_QUERY_key_sdc,      /* kDC / *4, STRING | ..shifted */
   n_TERMCAP_QUERY_key_eol,      /* kel/kE, STRING | clear-to-end-of-line */
   n_TERMCAP_QUERY_key_exit,     /* kext/@9, STRING */
   n_TERMCAP_QUERY_key_ic,       /* kich1/kI, STRING | insert character */
      n_TERMCAP_QUERY_key_sic,      /* kIC/#3, STRING | ..shifted */
   n_TERMCAP_QUERY_key_home,     /* khome/kh, STRING */
      n_TERMCAP_QUERY_key_shome,    /* kHOM/#2, STRING | ..shifted */
   n_TERMCAP_QUERY_key_end,      /* kend/@7, STRING */
      n_TERMCAP_QUERY_key_send,     /* kEND / *7, STRING | ..shifted */
   n_TERMCAP_QUERY_key_npage,    /* knp/kN, STRING */
   n_TERMCAP_QUERY_key_ppage,    /* kpp/kP, STRING */
   n_TERMCAP_QUERY_key_left,     /* kcub1/kl, STRING */
      n_TERMCAP_QUERY_key_sleft,    /* kLFT/#4, STRING | ..shifted */
      n_TERMCAP_QUERY_xkey_aleft,   /* kLFT3/-, STRING | X: Alt+left */
      n_TERMCAP_QUERY_xkey_cleft,   /* kLFT5/-, STRING | X: Control+left */
   n_TERMCAP_QUERY_key_right,    /* kcuf1/kr, STRING */
      n_TERMCAP_QUERY_key_sright,   /* kRIT/%i, STRING | ..shifted */
      n_TERMCAP_QUERY_xkey_aright,  /* kRIT3/-, STRING | X: Alt+right */
      n_TERMCAP_QUERY_xkey_cright,  /* kRIT5/-, STRING | X: Control+right */
   n_TERMCAP_QUERY_key_down,     /* kcud1/kd, STRING */
      n_TERMCAP_QUERY_xkey_sdown,   /* kDN/-, STRING | ..shifted */
      n_TERMCAP_QUERY_xkey_adown,   /* kDN3/-, STRING | X: Alt+down */
      n_TERMCAP_QUERY_xkey_cdown,   /* kDN5/-, STRING | X: Control+down */
   n_TERMCAP_QUERY_key_up,       /* kcuu1/ku, STRING */
      n_TERMCAP_QUERY_xkey_sup,     /* kUP/-, STRING | ..shifted */
      n_TERMCAP_QUERY_xkey_aup,     /* kUP3/-, STRING | X: Alt+up */
      n_TERMCAP_QUERY_xkey_cup,     /* kUP5/-, STRING | X: Control+up */
   n_TERMCAP_QUERY_kf0,          /* kf0/k0, STRING */
   n_TERMCAP_QUERY_kf1,          /* kf1/k1, STRING */
   n_TERMCAP_QUERY_kf2,          /* kf2/k2, STRING */
   n_TERMCAP_QUERY_kf3,          /* kf3/k3, STRING */
   n_TERMCAP_QUERY_kf4,          /* kf4/k4, STRING */
   n_TERMCAP_QUERY_kf5,          /* kf5/k5, STRING */
   n_TERMCAP_QUERY_kf6,          /* kf6/k6, STRING */
   n_TERMCAP_QUERY_kf7,          /* kf7/k7, STRING */
   n_TERMCAP_QUERY_kf8,          /* kf8/k8, STRING */
   n_TERMCAP_QUERY_kf9,          /* kf9/k9, STRING */
   n_TERMCAP_QUERY_kf10,         /* kf10/k;, STRING */
   n_TERMCAP_QUERY_kf11,         /* kf11/F1, STRING */
   n_TERMCAP_QUERY_kf12,         /* kf12/F2, STRING */
   n_TERMCAP_QUERY_kf13,         /* kf13/F3, STRING */
   n_TERMCAP_QUERY_kf14,         /* kf14/F4, STRING */
   n_TERMCAP_QUERY_kf15,         /* kf15/F5, STRING */
   n_TERMCAP_QUERY_kf16,         /* kf16/F6, STRING */
   n_TERMCAP_QUERY_kf17,         /* kf17/F7, STRING */
   n_TERMCAP_QUERY_kf18,         /* kf18/F8, STRING */
   n_TERMCAP_QUERY_kf19,         /* kf19/F9, STRING */
# endif /* HAVE_KEY_BINDINGS */

   n__TERMCAP_QUERY_MAX1
};
#endif /* n_HAVE_TCAP */

enum n_url_flags{
   n_URL_TLS_REQUIRED = 1<<0, /* Whether protocol always uses SSL/TLS.. */
   n_URL_TLS_OPTIONAL = 1<<1, /* ..may later upgrade to SSL/TLS */
   n_URL_TLS_MASK = n_URL_TLS_REQUIRED | n_URL_TLS_OPTIONAL,
   n_URL_HAD_USER = 1<<2,     /* Whether .url_user was part of the URL */
   n_URL_HOST_IS_NAME = 1<<3  /* .url_host not numeric address */
};

enum n_visual_info_flags{
   n_VISUAL_INFO_NONE,
   n_VISUAL_INFO_ONE_CHAR = 1<<0,         /* Step only one char, then return */
   n_VISUAL_INFO_SKIP_ERRORS = 1<<1,      /* Treat via replacement, step byte */
   n_VISUAL_INFO_WIDTH_QUERY = 1<<2,      /* Detect visual character widths */

   /* Rest only with HAVE_C90AMEND1, mutual with _ONE_CHAR */
   n_VISUAL_INFO_WOUT_CREATE = 1<<8,      /* Use/create .vic_woudat */
   n_VISUAL_INFO_WOUT_SALLOC = 1<<9,      /* ..salloc() it first */
   /* Only visuals into .vic_woudat - implies _WIDTH_QUERY */
   n_VISUAL_INFO_WOUT_PRINTABLE = 1<<10,
   n__VISUAL_INFO_FLAGS = n_VISUAL_INFO_WOUT_CREATE |
         n_VISUAL_INFO_WOUT_SALLOC | n_VISUAL_INFO_WOUT_PRINTABLE
};

enum n_program_option{
   n_PO_DEBUG = 1u<<0,        /* -d / *debug* */
   n_PO_VERB = 1u<<1,         /* -v / *verbose* */
   n_PO_VERBVERB = 1u<<2,     /* .. even more verbosity */
   n_PO_EXISTONLY = 1u<<3,    /* -e */
   n_PO_HEADERSONLY = 1u<<4,  /* -H */
   n_PO_HEADERLIST = 1u<<5,   /* -L */
   n_PO_QUICKRUN_MASK = n_PO_EXISTONLY | n_PO_HEADERSONLY | n_PO_HEADERLIST,
   n_PO_E_FLAG = 1u<<6,       /* -E / *skipemptybody* */
   n_PO_F_FLAG = 1u<<7,       /* -F */
   n_PO_Mm_FLAG = 1u<<8,      /* -M or -m (plus n_poption_arg_Mm) */
   n_PO_R_FLAG = 1u<<9,       /* -R */
   n_PO_r_FLAG = 1u<<10,      /* -r (plus n_poption_arg_r) */
   n_PO_S_FLAG_TEMPORARY = 1u<<11, /* -S about to set a variable */
   n_PO_t_FLAG = 1u<<12,      /* -t */
   n_PO_TILDE_FLAG = 1u<<13,  /* -~ */
   n_PO_BATCH_FLAG = 1u<<14,  /* -# */

   /*  */
   n_PO_MEMDEBUG = 1<<24,     /* *memdebug* */

   /* Some easy-access shortcuts */
   n_PO_D_V = n_PO_DEBUG | n_PO_VERB,
   n_PO_D_VV = n_PO_DEBUG | n_PO_VERBVERB,
   n_PO_D_V_VV = n_PO_DEBUG | n_PO_VERB | n_PO_VERBVERB
};

#define n_OBSOLETE(X) \
do{\
   if(n_poption & n_PO_D_V_VV)\
      n_err("%s: %s\n", _("Obsoletion warning"), X);\
}while(0)
#define n_OBSOLETE2(X,Y) \
do{\
   if(n_poption & n_PO_D_V_VV)\
      n_err("%s: %s: %s\n", _("Obsoletion warning"), X, Y);\
}while(0)

/* Program state bits which may regulary fluctuate */
enum n_program_state{
   n_PS_ROOT = 1u<<30,                 /* Temporary "bypass any checks" bit */
#define n_PS_ROOT_BLOCK(ACT) \
do{\
   bool_t a___reset___ = !(n_pstate & n_PS_ROOT);\
   n_pstate |= n_PS_ROOT;\
   ACT;\
   if(a___reset___)\
      n_pstate &= ~n_PS_ROOT;\
}while(0)

   /* XXX These are internal to the state machine and do not belong here,
    * XXX yet this was the easiest (accessible) approach */
   n_PS_ERR_XIT = 1u<<0,               /* Unless `ignerr' seen -> n_PSO_XIT */
   n_PS_ERR_QUIT = 1u<<1,              /* ..ditto: -> n_PSO_QUIT */
   n_PS_ERR_EXIT_MASK = n_PS_ERR_XIT | n_PS_ERR_QUIT,

   n_PS_SOURCING = 1u<<2,              /* During load() or `source' */
   n_PS_ROBOT = 1u<<3,                 /* .. even more robotic */
   n_PS_COMPOSE_MODE = 1u<<4,          /* State machine recursed */
   n_PS_COMPOSE_FORKHOOK = 1u<<5,      /* A hook running in a subprocess */

   n_PS_HOOK_NEWMAIL = 1u<<7,
   n_PS_HOOK = 1u<<8,
   n_PS_HOOK_MASK = n_PS_HOOK_NEWMAIL | n_PS_HOOK,

   n_PS_EDIT = 1u<<9,                  /* Current mailbox no "system mailbox" */
   n_PS_SETFILE_OPENED = 1u<<10,       /* (hack) setfile() opened a new box */
   n_PS_SAW_COMMAND = 1u<<11,          /* ..after mailbox switch */
   n_PS_DID_PRINT_DOT = 1u<<12,        /* Current message has been printed */

   n_PS_SIGWINCH_PEND = 1u<<13,        /* Need update of $COLUMNS/$LINES */
   n_PS_PSTATE_PENDMASK = n_PS_SIGWINCH_PEND, /* pstate housekeeping needed */

   n_PS_ARGLIST_MASK = n_BITENUM_MASK(14, 16),
   n_PS_ARGMOD_LOCAL = 1u<<14,         /* "local" modifier TODO struct CmdCtx */
   n_PS_ARGMOD_VPUT = 1u<<16,          /* "vput" modifier TODO struct CmdCtx */
   n_PS_MSGLIST_GABBY = 1u<<14,        /* getmsglist() saw something gabby */
   n_PS_MSGLIST_DIRECT = 1u<<15,       /* A msg was directly chosen by number */
   /* TODO HACK: until v15 PS_MSGLIST_SAW_NO is an indication whether an entry
    * TODO may be placed in the history or not (grep this, see commands()),
    * TODO so avoid reusing this bit */
   n_PS_WYSHLIST_SAW_CONTROL = 1u<<15, /* ..saw C0+ control characters */

   n_PS_EXPAND_MULTIRESULT = 1u<<17,   /* Last fexpand() with MULTIOK had .. */
   n_PS_ERRORS_PROMPT = 1u<<18,        /* New error to be reported in prompt */

   /* Bad hacks */
   n_PS_HEADER_NEEDED_MIME = 1u<<24,   /* mime_write_tohdr() not ASCII clean */
   n_PS_READLINE_NL = 1u<<25,          /* readline_input()+ saw a \n */
   n_PS_BASE64_STRIP_CR = 1u<<26       /* Go for text output, strip CR's */
};

/* Various states set once, and first time messages or initializers */
enum n_program_state_once{
   /* We have four program states: (0) pre getopt() done, (_GETOPT) pre rcfile
    * loaded etc., (_CONFIG) only -X evaluation missing still, followed by
    * _STARTED when we are fully setup */
   n_PSO_STARTED_GETOPT = 1u<<0,
   n_PSO_STARTED_CONFIG = 1u<<1,
   n_PSO_STARTED = 1u<<2,

   /* Exit request pending (quick) */
   n_PSO_XIT = 1u<<3,
   n_PSO_QUIT = 1u<<4,
   n_PSO_EXIT_MASK = n_PSO_XIT | n_PSO_QUIT,

   /* Pre _STARTED */
   n_PSO_BIG_ENDIAN = 1u<<5,
   n_PSO_UNICODE = 1u<<6,
   n_PSO_ENC_MBSTATE = 1u<<7,

   n_PSO_REPRODUCIBLE = 1u<<8,
   n_PSO_SENDMODE = 1u<<9,
   n_PSO_INTERACTIVE = 1u<<10,
   n_PSO_TTYIN = 1u<<11,
   n_PSO_TTYOUT = 1u<<12, /* TODO should be TTYERR! */

   /* "Later" */
   n_PSO_ATTACH_QUOTE_NOTED = 1u<<16,
   n_PSO_ERRORS_NOTED = 1u<<17,
   n_PSO_LINE_EDITOR_INIT = 1u<<18,
   n_PSO_RANDOM_INIT = 1u<<19,
   n_PSO_TERMCAP_DISABLE = 1u<<20,
   n_PSO_TERMCAP_CA_MODE = 1u<<21,

   /* TODO A subtile HACK which works in conjunction with n_OPT_t_FLAG so as
    * to allow to have multiple states regarding the related header setup */
   n_PSO_t_FLAG = 1u<<30
};

/* {{{ A large enum with all the boolean and value options a.k.a their keys.
 * Only the constant keys are in here, to be looked up via ok_[bv]look(),
 * ok_[bv]set() and ok_[bv]clear().
 * Variable properties are placed in {PROP=VALUE[:,PROP=VALUE:]} comments,
 * a {\} comment causes the next line to be read for (overlong) properties.
 * Notes:
 * - see the comments in accmacvar.c before changing *anything* in here!
 * - virt= implies rdonly,nodel
 * - import= implies env
 * - num and posnum are mutual exclusive
 * - most default VAL_ues come from in from build system via ./make.rc
 * (Keep in SYNC: ./nail.h:okeys, ./nail.rc, ./nail.1:"Initial settings") */
enum okeys {
   /* This is used for all macro(-local) variables etc., i.e.,
    * [*@#]|[1-9][0-9]*, in order to have something with correct properties.
    * It is also used for the ${^.+} multiplexer */
   ok_v___special_param,   /* {nolopts=1,rdonly=1,nodel=1} */
   /*__qm/__em aka ?/! should be num=1 but that more expensive than what now */
   ok_v___qm,              /* {name=?,nolopts=1,rdonly=1,nodel=1} */
   ok_v___em,              /* {name=!,nolopts=1,rdonly=1,nodel=1} */

   ok_v_account,                       /* {nolopts=1,rdonly=1,nodel=1} */
   ok_b_add_file_recipients,
ok_v_agent_shell_lookup,
   ok_b_allnet,
   ok_b_append,
   /* *ask* is auto-mapped to *asksub* as imposed by standard! */
   ok_b_ask,                           /* {vip=1} */
   ok_b_askatend,
   ok_b_askattach,
   ok_b_askbcc,
   ok_b_askcc,
   ok_b_asksign,
   ok_b_asksend,                       /* {i3val=TRU1} */
   ok_b_asksub,                        /* {i3val=TRU1} */
   ok_v_attrlist,
   ok_v_autobcc,
   ok_v_autocc,
   ok_b_autocollapse,
   ok_b_autoprint,
ok_b_autothread,
   ok_v_autosort,

   ok_b_bang,
ok_b_batch_exit_on_error,
   ok_v_bind_timeout,                  /* {notempty=1,posnum=1} */
ok_b_bsdannounce,
   ok_b_bsdcompat,
   ok_b_bsdflags,
   ok_b_bsdheadline,
   ok_b_bsdmsgs,
   ok_b_bsdorder,
   ok_v_build_os,                      /* {virt=VAL_BUILD_OS} */
   ok_v_build_osenv,                   /* {virt=VAL_BUILD_OSENV} */

   ok_v_COLUMNS,                       /* {notempty=1,posnum=1,env=1} */
   ok_v_charset_7bit,            /* {lower=1,notempty=1,defval=CHARSET_7BIT} */
   /* But unused without HAVE_ICONV, we use ok_vlook(CHARSET_8BIT_OKEY)! */
   ok_v_charset_8bit,            /* {lower=1,notempty=1,defval=CHARSET_8BIT} */
   ok_v_charset_unknown_8bit,          /* {lower=1} */
   ok_v_cmd,
   ok_b_colour_disable,
   ok_b_colour_pager,
   ok_v_contact_mail,                  /* {virt=VAL_CONTACT_MAIL} */
   ok_v_contact_web,                   /* {virt=VAL_CONTACT_WEB} */
   ok_v_crt,                           /* {posnum=1} */
   ok_v_customhdr,                     /* {nocntrls=1} */

   ok_v_DEAD,                          /* {notempty=1,env=1,defval=VAL_DEAD} */
   ok_v_datefield,                     /* {i3val="%Y-%m-%d %H:%M"} */
   ok_v_datefield_markout_older,       /* {i3val="%Y-%m-%d"} */
   ok_b_debug,                         /* {vip=1} */
   ok_b_disposition_notification_send,
   ok_b_dot,
   ok_b_dotlock_ignore_error,

   ok_v_EDITOR,                     /* {env=1,notempty=1,defval=VAL_EDITOR} */
   ok_b_editalong,
   ok_b_editheaders,
   ok_b_emptystart,
ok_v_encoding,
   ok_b_errexit,
   ok_v_escape,                        /* {defval=n_ESCAPE} */
   ok_v_expandaddr,
   ok_v_expandargv,

   ok_v_features,                      /* {virt=VAL_FEATURES} */
   ok_b_flipr,
   ok_v_folder,                        /* {vip=1} */
   ok_v_folder_resolved,               /* {rdonly=1,nodel=1} */
   ok_v_folder_hook,
   ok_b_followup_to,
   ok_v_followup_to_honour,
   ok_b_forward_as_attachment,
   ok_v_forward_inject_head,
   ok_v_from,
   ok_b_fullnames,
ok_v_fwdheading,

   ok_v_HOME,                          /* {vip=1,nodel=1,notempty=1,import=1} */
   ok_b_header,                        /* {i3val=TRU1} */
   ok_v_headline,
   ok_v_headline_bidi,
   ok_v_history_file,
   ok_b_history_gabby,
   ok_b_history_gabby_persist,
   ok_v_history_size,                  /* {notempty=1,posnum=1} */
   ok_b_hold,
   ok_v_hostname,

   ok_b_idna_disable,
   ok_v_ifs,                           /* {vip=1,defval=" \t\n"} */
   ok_v_ifs_ws,                     /* {vip=1,rdonly=1,nodel=1,i3val=" \t\n"} */
   ok_b_ignore,
   ok_b_ignoreeof,
   ok_v_inbox,
   ok_v_indentprefix,                  /* {defval="\t"} */

   ok_b_keep,
   ok_b_keep_content_length,
   ok_b_keepsave,

   ok_v_LANG,                          /* {vip=1,env=1,notempty=1} */
   ok_v_LC_ALL,                     /* {name=LC_ALL,vip=1,env=1,notempty=1} */
   ok_v_LC_CTYPE,                   /* {name=LC_CTYPE,vip=1,env=1,notempty=1} */
   ok_v_LINES,                         /* {notempty=1,posnum=1,env=1} */
   ok_v_LISTER,                     /* {env=1,notempty=1,defval=VAL_LISTER} */
   ok_v_LOGNAME,                       /* {rdonly=1,import=1} */
   ok_b_line_editor_disable,
   ok_b_line_editor_no_defaults,
   ok_v_log_prefix,                    /* {nodel=1,i3val=VAL_UAGENT ": "} */

   ok_v_MAIL,                          /* {env=1} */
   ok_v_MAILRC,                  /* {import=1,notempty=1,defval=VAL_MAILRC} */
   ok_b_MAILX_NO_SYSTEM_RC,            /* {name=MAILX_NO_SYSTEM_RC,import=1} */
   ok_v_MBOX,                          /* {env=1,notempty=1,defval=VAL_MBOX} */
   ok_v_mailbox_resolved,              /* {nolopts=1,rdonly=1,nodel=1} */
   ok_v_mailbox_display,               /* {nolopts=1,rdonly=1,nodel=1} */
   ok_v_mailx_extra_rc,
   ok_b_markanswered,
   ok_b_mbox_rfc4155,
   ok_b_memdebug,                      /* {vip=1} */
   ok_b_message_id_disable,
   ok_v_message_inject_head,
   ok_v_message_inject_tail,
   ok_b_metoo,
   ok_b_mime_allow_text_controls,
   ok_b_mime_alternative_favour_rich,
   ok_v_mime_counter_evidence,         /* {posnum=1} */
   ok_v_mime_encoding,
   ok_v_mimetypes_load_control,
   ok_v_mta,                           /* {notempty=1,defval=VAL_MTA} */
   ok_v_mta_arguments,
   ok_b_mta_no_default_arguments,
   ok_b_mta_no_receiver_arguments,
   ok_v_mta_argv0,                     /* {notempty=1,defval=VAL_MTA_ARGV0} */

   /* TODO likely temporary hook data, v15 drop */
   ok_v_mailx_command,                 /* {rdonly=1,nodel=1} */
   ok_v_mailx_subject,                 /* {rdonly=1,nodel=1} */
   ok_v_mailx_from,                    /* {rdonly=1,nodel=1} */
   ok_v_mailx_sender,                  /* {rdonly=1,nodel=1} */
   ok_v_mailx_to,                      /* {rdonly=1,nodel=1} */
   ok_v_mailx_cc,                      /* {rdonly=1,nodel=1} */
   ok_v_mailx_bcc,                     /* {rdonly=1,nodel=1} */
   ok_v_mailx_raw_to,                  /* {rdonly=1,nodel=1} */
   ok_v_mailx_raw_cc,                  /* {rdonly=1,nodel=1} */
   ok_v_mailx_raw_bcc,                 /* {rdonly=1,nodel=1} */
   ok_v_mailx_orig_from,               /* {rdonly=1,nodel=1} */
   ok_v_mailx_orig_to,                 /* {rdonly=1,nodel=1} */
   ok_v_mailx_orig_cc,                 /* {rdonly=1,nodel=1} */
   ok_v_mailx_orig_bcc,                /* {rdonly=1,nodel=1} */

ok_v_NAIL_EXTRA_RC,                 /* {name=NAIL_EXTRA_RC} */
ok_b_NAIL_NO_SYSTEM_RC,             /* {name=NAIL_NO_SYSTEM_RC,import=1} */
ok_v_NAIL_HEAD,                     /* {name=NAIL_HEAD} */
ok_v_NAIL_HISTFILE,                 /* {name=NAIL_HISTFILE} */
ok_v_NAIL_HISTSIZE,                 /* {name=NAIL_HISTSIZE,notempty=1,num=1} */
ok_v_NAIL_TAIL,                     /* {name=NAIL_TAIL} */
   ok_v_NETRC,                         /* {env=1,notempty=1,defval=VAL_NETRC} */
   ok_b_netrc_lookup,                  /* {chain=1} */
   ok_v_netrc_pipe,
   ok_v_newfolders,
   ok_v_newmail,

   ok_v_on_account_cleanup,            /* {notempty=1} */
   ok_v_on_compose_cleanup,            /* {notempty=1} */
   ok_v_on_compose_enter,              /* {notempty=1} */
   ok_v_on_compose_leave,              /* {notempty=1} */
   ok_v_on_compose_splice,             /* {notempty=1} */
   ok_v_on_compose_splice_shell,       /* {notempty=1} */
   ok_v_on_resend_cleanup,             /* {notempty=1} */
   ok_v_on_resend_enter,               /* {notempty=1} */
   ok_b_outfolder,

   ok_v_PAGER,                         /* {env=1,notempty=1,defval=VAL_PAGER} */
   ok_v_PATH,                          /* {nodel=1,import=1} */
   ok_b_POSIXLY_CORRECT,            /* {vip=1,import=1,name=POSIXLY_CORRECT} */
   ok_b_page,
   ok_v_password,                      /* {chain=1} */
   ok_b_piperaw,
   ok_v_pop3_auth,                     /* {chain=1} */
   ok_b_pop3_bulk_load,
   ok_v_pop3_keepalive,                /* {notempty=1,posnum=1} */
   ok_b_pop3_no_apop,                  /* {chain=1} */
   ok_b_pop3_use_starttls,             /* {chain=1} */
   ok_b_posix,                         /* {vip=1} */
   ok_b_print_alternatives,
   ok_v_prompt,                        /* {i3val="? "} */
   ok_v_prompt2,                       /* {i3val=".. "} */

   ok_b_quiet,
   ok_v_quote,
   ok_b_quote_as_attachment,
   ok_v_quote_chars,                   /* {vip=1,notempty=1,defval=">|}:"} */
   ok_v_quote_fold,

   ok_b_r_option_implicit,
   ok_b_recipients_in_cc,
   ok_v_record,
   ok_b_record_files,
   ok_b_record_resent,
   ok_b_reply_in_same_charset,
   ok_v_reply_strings,
ok_v_replyto,
   ok_v_reply_to,                      /* {notempty=1} */
   ok_v_reply_to_honour,
   ok_b_rfc822_body_from_,             /* {name=rfc822-body-from_} */

   ok_v_SHELL,                      /* {import=1,notempty=1,defval=VAL_SHELL} */
ok_b_SYSV3,                         /* {env=1} */
   ok_b_save,                          /* {i3val=TRU1} */
   ok_v_screen,                        /* {notempty=1,posnum=1} */
   ok_b_searchheaders,
   ok_v_sendcharsets,                  /* {lower=1} */
   ok_b_sendcharsets_else_ttycharset,
   ok_v_sender,
ok_v_sendmail,
ok_v_sendmail_arguments,
ok_b_sendmail_no_default_arguments,
ok_v_sendmail_progname,
   ok_b_sendwait,
   ok_b_showlast,
   ok_b_showname,
   ok_b_showto,
   ok_v_Sign,
   ok_v_sign,
ok_v_signature,
   ok_b_skipemptybody,                 /* {vip=1} */
   ok_v_smime_ca_dir,
   ok_v_smime_ca_file,
   ok_v_smime_ca_flags,
   ok_b_smime_ca_no_defaults,
   ok_v_smime_cipher,                  /* {chain=1} */
   ok_v_smime_crl_dir,
   ok_v_smime_crl_file,
   ok_v_smime_encrypt,                 /* {chain=1} */
   ok_b_smime_force_encryption,
ok_b_smime_no_default_ca,
   ok_b_smime_sign,
   ok_v_smime_sign_cert,               /* {chain=1} */
   ok_v_smime_sign_include_certs,      /* {chain=1} */
   ok_v_smime_sign_message_digest,     /* {chain=1} */
ok_v_smtp,
   ok_v_smtp_auth,                     /* {chain=1} */
ok_v_smtp_auth_password,
ok_v_smtp_auth_user,
   ok_v_smtp_hostname,
   ok_b_smtp_use_starttls,             /* {chain=1} */
   ok_v_SOURCE_DATE_EPOCH,             /* {\} */
      /* {name=SOURCE_DATE_EPOCH,rdonly=1,import=1,notempty=1,posnum=1} */
   ok_v_socks_proxy,                   /* {chain=1,notempty=1} */
   ok_v_spam_interface,
   ok_v_spam_maxsize,                  /* {notempty=1,posnum=1} */
   ok_v_spamc_command,
   ok_v_spamc_arguments,
   ok_v_spamc_user,
ok_v_spamd_socket,
ok_v_spamd_user,
   ok_v_spamfilter_ham,
   ok_v_spamfilter_noham,
   ok_v_spamfilter_nospam,
   ok_v_spamfilter_rate,
   ok_v_spamfilter_rate_scanscore,
   ok_v_spamfilter_spam,
   ok_v_ssl_ca_dir,                    /* {chain=1} */
   ok_v_ssl_ca_file,                   /* {chain=1} */
   ok_v_ssl_ca_flags,                  /* {chain=1} */
   ok_b_ssl_ca_no_defaults,            /* {chain=1} */
ok_v_ssl_cert,                         /* {chain=1} */
ok_v_ssl_cipher_list,                  /* {chain=1} */
   ok_v_ssl_config_file,
   ok_v_ssl_config_module,             /* {chain=1} */
   ok_v_ssl_config_pairs,              /* {chain=1} */
ok_v_ssl_curves,                    /* {chain=1} */
   ok_v_ssl_crl_dir,
   ok_v_ssl_crl_file,
   ok_v_ssl_features,                  /* {virt=VAL_SSL_FEATURES} */
ok_v_ssl_key,                       /* {chain=1} */
ok_v_ssl_method,                    /* {chain=1} */
ok_b_ssl_no_default_ca,
ok_v_ssl_protocol,                  /* {chain=1} */
   ok_v_ssl_rand_egd,
   ok_v_ssl_rand_file,
   ok_v_ssl_verify,                    /* {chain=1} */
   ok_v_stealthmua,

   ok_v_TERM,                          /* {env=1} */
   ok_v_TMPDIR,            /* {import=1,vip=1,notempty=1,defval=VAL_TMPDIR} */
   ok_v_termcap,
   ok_b_termcap_ca_mode,
   ok_b_termcap_disable,
   ok_v_toplines,                      /* {notempty=1,num=1,defval="5"} */
   ok_b_topsqueeze,
   ok_v_ttycharset,              /* {lower=1,notempty=1,defval=CHARSET_8BIT} */
   ok_b_typescript_mode,               /* {vip=1} */

   ok_v_USER,                          /* {rdonly=1,import=1} */
   ok_v_umask,                      /* {vip=1,nodel=1,posnum=1,i3val="0077"} */
   ok_v_user,                       /* {chain=1} */

   ok_v_VISUAL,                     /* {env=1,notempty=1,defval=VAL_VISUAL} */
   ok_b_v15_compat,
   ok_b_verbose,                       /* {vip=1} */
   ok_v_version,                       /* {virt=n_VERSION} */
   ok_v_version_date,                  /* {virt=n_VERSION_DATE} */
   ok_v_version_hexnum,                /* {virt=n_VERSION_HEXNUM,posnum=1} */
   ok_v_version_major,                 /* {virt=n_VERSION_MAJOR,posnum=1} */
   ok_v_version_minor,                 /* {virt=n_VERSION_MINOR,posnum=1} */
   ok_v_version_update,                /* {virt=n_VERSION_UPDATE,posnum=1} */

   ok_b_writebackedited

,  /* Obsolete IMAP related non-sorted */
ok_b_disconnected,               /* {chain=1} */
ok_v_imap_auth,                  /* {chain=1} */
ok_v_imap_cache,
ok_v_imap_delim,                 /* {chain=1} */
ok_v_imap_keepalive,             /* {chain=1} */
ok_v_imap_list_depth,
ok_b_imap_use_starttls           /* {chain=1} */
}; /* }}} */

/* Locale-independent character classes */
enum {
   C_CNTRL        = 1<<0,
   C_BLANK        = 1<<1,
   C_WHITE        = 1<<2,
   C_SPACE        = 1<<3,
   C_PUNCT        = 1<<4,
   C_OCTAL        = 1<<5,
   C_DIGIT        = 1<<6,
   C_UPPER        = 1<<7,
   C_LOWER        = 1<<8
};

struct str {
   char     *s;      /* the string's content */
   size_t   l;       /* the stings's length */
};

struct n_string{
   char *s_dat;         /*@ May contain NULs, not automatically terminated */
   ui32_t s_len;        /*@ gth of string */
   ui32_t s_auto : 1;   /* Stored in auto-reclaimed storage? */
   ui32_t s_size : 31;  /* of .s_dat, -1 */
};

struct n_strlist{
   struct n_strlist *sl_next;
   size_t sl_len;
   char sl_dat[n_VFIELD_SIZE(0)];
};
#define n_STRLIST_ALLOC(SZ) /* XXX -> nailfuns.h (and pimp interface) */\
   n_alloc(n_VSTRUCT_SIZEOF(struct n_strlist, sl_dat) + (SZ) +1)
#define n_STRLIST_AUTOREC_ALLOC(SZ) \
   n_autorec_alloc(n_VSTRUCT_SIZEOF(struct n_strlist, sl_dat) + (SZ) +1)
#define n_STRLIST_LOFI_ALLOC(SZ) \
   n_lofi_alloc(n_VSTRUCT_SIZEOF(struct n_strlist, sl_dat) + (SZ) +1)

struct bidi_info {
   struct str  bi_start;      /* Start of (possibly) bidirectional text */
   struct str  bi_end;        /* End of ... */
   size_t      bi_pad;        /* No of visual columns to reserve for BIDI pad */
};

struct n_cmd_arg_desc{
   char cad_name[12];   /* Name of command */
   ui32_t cad_no;       /* Number of entries in cad_ent_flags */
   /* [enum n_cmd_arg_desc_flags,arg-dep] */
   ui32_t cad_ent_flags[n_VFIELD_SIZE(0)][2];
};
/* ISO C(99) doesn't allow initialization of "flex array" */
#define n_CMD_ARG_DESC_SUBCLASS_DEF(CMD,NO,VAR) \
   struct n_cmd_arg_desc_ ## CMD {\
      char cad_name[12];\
      ui32_t cad_no;\
      ui32_t cad_ent_flags[NO][2];\
   } const VAR = { #CMD "\0", NO,
#define n_CMD_ARG_DESC_SUBCLASS_DEF_END }
#define n_CMD_ARG_DESC_SUBCLASS_CAST(P) ((struct n_cmd_arg_desc const*)P)

struct n_cmd_arg_ctx{
   struct n_cmd_arg_desc const *cac_desc; /* Input: description of command */
   char const *cac_indat;     /* Input that shall be parsed */
   size_t cac_inlen;          /* Input length (UIZ_MAX: do a strlen()) */
   size_t cac_no;             /* Output: number of parsed arguments */
   struct n_cmd_arg *cac_arg; /* Output: parsed arguments */
   char const *cac_vput;      /* "Output": vput prefix used: varname */
};

struct n_cmd_arg{/* TODO incomplete, misses getmsglist() */
   struct n_cmd_arg *ca_next;
   char const *ca_indat;   /*[PRIV] Pointer into n_cmd_arg_ctx.cac_indat */
   size_t ca_inlen;        /*[PRIV] of .ca_indat of this arg (not terminated) */
   ui32_t ca_ent_flags[2]; /* Copy of n_cmd_arg_desc.cad_ent_flags[X] */
   ui32_t ca_arg_flags;    /* [Output: _WYSH: copy of parse result flags] */
   ui8_t ca__dummy[4];
   union{
      struct str ca_str;      /* _STRING, _WYSH */
   } ca_arg;               /* Output: parsed result */
};

struct n_cmd_desc{
   char const *cd_name;    /* Name of command */
   int (*cd_func)(void*);  /* Implementor of command */
   enum n_cmd_arg_flags cd_caflags;
   si16_t cd_msgflag;      /* Required flags of msgs */
   si16_t cd_msgmask;      /* Relevant flags of msgs */
   struct n_cmd_arg_desc const *cd_cadp;
#ifdef HAVE_DOCSTRINGS
   char const *cd_doc;     /* One line doc for command */
#endif
};
/* Yechh, can't initialize unions */
#define cd_minargs cd_msgflag /* Minimum argcount for WYSH/WYRA/RAWLIST */
#define cd_maxargs cd_msgmask /* Max argcount for WYSH/WYRA/RAWLIST */

#ifdef HAVE_COLOUR
struct n_colour_env{
   struct n_colour_env *ce_last;
   bool_t ce_enabled;   /* Colour enabled on this level */
   ui8_t ce_ctx;        /* enum n_colour_ctx */
   ui8_t ce_ispipe;     /* .ce_outfp known to be a pipe */
   ui8_t ce__pad[5];
   FILE *ce_outfp;
   struct a_colour_map *ce_current; /* Active colour or NULL */
};

struct n_colour_pen;
#endif

struct url {
   char const     *url_input;       /* Input as given (really) */
   ui32_t         url_flags;
   ui8_t          url_cproto;       /* enum cproto as given */
   ui8_t          url__pad1[1];
   ui16_t         url_portno;       /* atoi .url_port or default, host endian */
   char const     *url_port;        /* Port (if given) or NULL */
   char           url_proto[14];    /* Communication protocol as 'xy\0//' */
   ui8_t          url_proto_len;    /* Length of .url_proto ('\0' index) */
   ui8_t          url_proto_xlen;   /* .. if '\0' is replaced with ':' */
   struct str     url_user;         /* User, exactly as given / looked up */
   struct str     url_user_enc;     /* User, urlxenc()oded */
   struct str     url_pass;         /* Pass (urlxdec()oded) or NULL */
   /* TODO we don't know whether .url_host is a name or an address.  Us
    * TODO Net::IPAddress::fromString() to check that, then set
    * TODO n_URL_HOST_IS_NAME solely based on THAT!  Until then,
    * TODO n_URL_HOST_IS_NAME ONLY set if n_URL_TLS_MASK and HAVE_GETADDRINFO */
   struct str     url_host;         /* Service hostname TODO we don't know */
   struct str     url_path;         /* Path suffix or NULL */
   /* TODO: url_get_component(url *, enum COMPONENT, str *store) */
   struct str     url_h_p;          /* .url_host[:.url_port] */
   /* .url_user@.url_host
    * Note: for CPROTO_SMTP this may resolve HOST via *smtp-hostname* (->
    * *hostname*)!  (And may later be overwritten according to *from*!) */
   struct str     url_u_h;
   struct str     url_u_h_p;        /* .url_user@.url_host[:.url_port] */
   struct str     url_eu_h_p;       /* .url_user_enc@.url_host[:.url_port] */
   char const     *url_p_u_h_p;     /* .url_proto://.url_u_h_p */
   char const     *url_p_eu_h_p;    /* .url_proto://.url_eu_h_p */
   char const     *url_p_eu_h_p_p;  /* .url_proto://.url_eu_h_p[/.url_path] */
};

struct ccred {
   enum cproto    cc_cproto;     /* Communication protocol */
   enum authtype  cc_authtype;   /* Desired authentication */
   char const     *cc_auth;      /* Authentication type as string */
   struct str     cc_user;       /* User (urlxdec()oded) or NULL */
   struct str     cc_pass;       /* Password (urlxdec()oded) or NULL */
};

#ifdef HAVE_DOTLOCK
struct n_dotlock_info{
   char const *di_file_name;  /* Mailbox to lock */
   char const *di_lock_name;  /* .di_file_name + .lock */
   char const *di_hostname;   /* ..filled in parent (due resolver delays) */
   char const *di_randstr;    /* ..ditto, random string */
   size_t di_pollmsecs;       /* Delay in between locking attempts */
   struct stat *di_stb;
};
#endif

struct n_file_type{
   char const *ft_ext_dat;    /* Extension this handles, without first period */
   size_t ft_ext_len;
   char const *ft_load_dat;   /* And the load and save command strings */
   size_t ft_load_len;
   char const *ft_save_dat;
   size_t ft_save_len;
};

struct n_go_data_ctx{
   /* The memory pool may be inherited from outer context, so we
    * .gdc_mempool may be NE .gdc__mempool_buf */
   void *gdc_mempool;
   void *gdc_ifcond; /* Saved state of conditional stack */
#ifdef HAVE_COLOUR
   struct n_colour_env *gdc_colour;
   bool_t gdc_colour_active;
   ui8_t gdc__colour_pad[7];
# define n_COLOUR_IS_ACTIVE() \
   (/*n_go_data->gc_data.gdc_colour != NULL &&*/\
    /*n_go_data->gc_data.gdc_colour->ce_enabled*/ n_go_data->gdc_colour_active)
#endif
   char gdc__mempool_buf[n_MEMORY_POOL_TYPE_SIZEOF];
};
n_MCTA(n_MEMORY_POOL_TYPE_SIZEOF % sizeof(void*) == 0,
   "Inacceptible size of n_go_data_ctx.gdc_mempool")

struct mime_handler {
   enum mime_handler_flags mh_flags;
   struct str  mh_msg;           /* Message describing this command */
   /* XXX union{} the following? */
   char const  *mh_shell_cmd;    /* For MIME_HDL_CMD */
   int         (*mh_ptf)(void);  /* PTF main() for MIME_HDL_PTF */
};

struct quoteflt {
   FILE        *qf_os;        /* Output stream */
   char const  *qf_pfix;
   ui32_t      qf_pfix_len;   /* Length of prefix: 0: bypass */
   ui32_t      qf_qfold_min;  /* Simple way: wrote prefix? */
   /* TODO quoteflt.qf_nl_last is a hack that i have introduced so that we
    * TODO finally can gracefully place a newline last in the visual display.
    * TODO I.e., for cases where quoteflt shouldn't be used at all ;} */
   bool_t      qf_nl_last;    /* Last thing written/seen was NL */
#ifndef HAVE_QUOTE_FOLD
   ui8_t       __dummy[7];
#else
   ui8_t       __dummy[1];
   ui8_t       qf_state;      /* *quote-fold* state machine */
   bool_t      qf_brk_isws;   /* Breakpoint is at WS */
   ui32_t      qf_qfold_max;  /* Otherwise: line lengths */
   ui32_t      qf_wscnt;      /* Whitespace count */
   char const *qf_quote_chars; /* *quote-chars* */
   ui32_t      qf_brkl;       /* Breakpoint */
   ui32_t      qf_brkw;       /* Visual width, breakpoint */
   ui32_t      qf_datw;       /* Current visual output line width */
   struct str  qf_dat;        /* Current visual output line */
   struct str  qf_currq;      /* Current quote, compressed */
   mbstate_t   qf_mbps[2];
#endif
};

#ifdef HAVE_FILTER_HTML_TAGSOUP
struct htmlflt {
   FILE        *hf_os;        /* Output stream */
   ui32_t      hf_flags;
   ui32_t      hf_lmax;       /* Maximum byte +1 in .hf_line/4 */
   ui32_t      hf_len;        /* Current bytes in .hf_line */
   ui32_t      hf_last_ws;    /* Last whitespace on line (fold purposes) */
   ui32_t      hf_mboff;      /* Last offset for "mbtowc" */
   ui32_t      hf_mbwidth;    /* We count characters not bytes if possible */
   char        *hf_line;      /* Output line buffer - MUST be last field! */
   si32_t      hf_href_dist;  /* Count of lines since last HREF flush */
   ui32_t      hf_href_no;    /* HREF sequence number */
   struct htmlflt_href *hf_hrefs;
   struct htmlflt_tag const *hf_ign_tag; /* Tag that will end ignore mode */
   char        *hf_curr;      /* Current cursor into .hf_bdat */
   char        *hf_bmax;      /* Maximum byte in .hf_bdat +1 */
   char        *hf_bdat;      /* (Temporary) Tag content data storage */
};
#endif

struct search_expr {
   /* XXX Type of search should not be evaluated but be enum */
   bool_t ss_field_exists; /* Only check whether field spec. exists */
   bool_t ss_skin;         /* Shall work on (skin()ned) addresses */
   ui8_t ss__pad[6];
   char const *ss_field;   /* Field spec. where to search (not always used) */
   char const *ss_body;    /* Field body search expression */
#ifdef HAVE_REGEX
   regex_t *ss_fieldre;    /* Could be instead of .ss_field */
   regex_t *ss_bodyre;     /* Ditto, .ss_body */
   regex_t ss__fieldre_buf;
   regex_t ss__bodyre_buf;
#endif
};

/* This is somewhat temporary for pre v15 */
struct n_sigman{
   ui32_t sm_flags;           /* enum n_sigman_flags */
   int sm_signo;
   struct n_sigman *sm_outer;
   sighandler_type sm_ohup;
   sighandler_type sm_oint;
   sighandler_type sm_oquit;
   sighandler_type sm_oterm;
   sighandler_type sm_opipe;
   sigjmp_buf sm_jump;
};

struct n_timespec{
   si64_t ts_sec;
   siz_t ts_nsec;
};

struct termios_state {
   struct termios ts_tios;
   char        *ts_linebuf;
   size_t      ts_linesize;
   bool_t      ts_needs_reset;
};

#define termios_state_reset() \
do {\
   if (termios_state.ts_needs_reset) {\
      tcsetattr(STDIN_FILENO, TCSADRAIN, &termios_state.ts_tios);\
      termios_state.ts_needs_reset = FAL0;\
   }\
} while (0)

#ifdef n_HAVE_TCAP
struct n_termcap_value{
   enum n_termcap_captype tv_captype;
   ui8_t tv__dummy[4];
   union n_termcap_value_data{
      bool_t tvd_bool;
      ui32_t tvd_numeric;
      char const *tvd_string;
   } tv_data;
};
#endif

struct n_visual_info_ctx{
   char const *vic_indat;  /*I Input data */
   size_t vic_inlen;       /*I If UIZ_MAX, strlen(.vic_indat) */
   char const *vic_oudat;  /*O remains */
   size_t vic_oulen;
   size_t vic_chars_seen;  /*O number of characters processed */
   size_t vic_bytes_seen;  /*O number of bytes passed */
   size_t vic_vi_width;    /*[O] visual width of the entire range */
   wc_t *vic_woudat;       /*[O] if so requested */
   size_t vic_woulen;      /*[O] entries in .vic_woudat, if used */
   wc_t vic_waccu;         /*O The last wchar_t/char processed (if any) */
   enum n_visual_info_flags vic_flags; /*O Copy of parse flags */
   /* TODO bidi */
#ifdef HAVE_C90AMEND1
   mbstate_t *vic_mbstate; /*IO .vic_mbs_def used if NULL */
   mbstate_t vic_mbs_def;
#endif
};

struct time_current {
   time_t      tc_time;
   struct tm   tc_gm;
   struct tm   tc_local;
   char        tc_ctime[32];
};

struct sock {                 /* data associated with a socket */
   int         s_fd;          /* file descriptor */
#ifdef HAVE_SSL
   int         s_use_ssl;     /* SSL is used */
# ifdef HAVE_XSSL
   void        *s_ssl;        /* SSL object */
# endif
#endif
   char        *s_wbuf;       /* for buffered writes */
   int         s_wbufsize;    /* allocated size of s_buf */
   int         s_wbufpos;     /* position of first empty data byte */
   char        *s_rbufptr;    /* read pointer to s_rbuf */
   int         s_rsz;         /* size of last read in s_rbuf */
   char const  *s_desc;       /* description of error messages */
   void        (*s_onclose)(void);     /* execute on close */
   char        s_rbuf[LINESIZE + 1];   /* for buffered reads */
};

struct sockconn {
   struct url     sc_url;
   struct ccred   sc_cred;
   struct sock    sc_sock;
};

struct mailbox {
   enum {
      MB_NONE     = 000,      /* no reply expected */
      MB_COMD     = 001,      /* command reply expected */
      MB_MULT     = 002,      /* multiline reply expected */
      MB_PREAUTH  = 004,      /* not in authenticated state */
      MB_BYE      = 010,      /* may accept a BYE state */
      MB_FROM__WARNED = 1<<4  /* MBOX with invalid from seen & logged */
   }           mb_active;
   FILE        *mb_itf;       /* temp file with messages, read open */
   FILE        *mb_otf;       /* same, write open */
   char        *mb_sorted;    /* sort method */
   enum {
      MB_VOID,    /* no type (e. g. connection failed) */
      MB_FILE,    /* local file */
      MB_POP3,    /* POP3 mailbox */
MB_IMAP,          /* IMAP mailbox */
MB_CACHE,         /* IMAP cache */
      MB_MAILDIR  /* maildir folder */
   }           mb_type;       /* type of mailbox */
   enum {
      MB_DELE = 01,  /* may delete messages in mailbox */
      MB_EDIT = 02   /* may edit messages in mailbox */
   }           mb_perm;
   int mb_threaded;           /* mailbox has been threaded */
#ifdef HAVE_IMAP
   enum mbflags {
      MB_NOFLAGS  = 000,
      MB_UIDPLUS  = 001 /* supports IMAP UIDPLUS */
   }           mb_flags;
   unsigned long  mb_uidvalidity;   /* IMAP unique identifier validity */
   char        *mb_imap_account;    /* name of current IMAP account */
   char        *mb_imap_pass;       /* xxx v15-compat URL workaround */
   char        *mb_imap_mailbox;    /* name of current IMAP mailbox */
   char        *mb_cache_directory; /* name of cache directory */
   char mb_imap_delim[8];     /* Directory separator(s), [0] += replacer */
#endif
   struct sock mb_sock;       /* socket structure */
};

enum needspec {
   NEED_UNSPEC,      /* unspecified need, don't fetch */
   NEED_HEADER,      /* need the header of a message */
   NEED_BODY         /* need header and body of a message */
};

enum content_info {
   CI_NOTHING,                /* Nothing downloaded yet */
   CI_HAVE_HEADER = 1u<<0,    /* Header is downloaded */
   CI_HAVE_BODY = 1u<<1,      /* Entire message is downloaded */
   CI_HAVE_MASK = CI_HAVE_HEADER | CI_HAVE_BODY,
   CI_MIME_ERRORS = 1u<<2,    /* Defective MIME structure */
   CI_EXPANDED = 1u<<3,       /* Container part (pk7m) exploded into X */
   CI_SIGNED = 1u<<4,         /* Has a signature.. */
   CI_SIGNED_OK = 1u<<5,      /* ..verified ok.. */
   CI_SIGNED_BAD = 1u<<6,     /* ..verified bad (missing key).. */
   CI_ENCRYPTED = 1u<<7,      /* Is encrypted.. */
   CI_ENCRYPTED_OK = 1u<<8,   /* ..decryption possible/ok.. */
   CI_ENCRYPTED_BAD = 1u<<9   /* ..not possible/ok */
};

/* Note: flags that are used in obs-imap-cache.c may not change */
enum mflag {
   MUSED = 1u<<0,       /* entry is used, but this bit isn't */
   MDELETED = 1u<<1,    /* entry has been deleted */
   MSAVED = 1u<<2,      /* entry has been saved */
   MTOUCH = 1u<<3,      /* entry has been noticed */
   MPRESERVE = 1u<<4,   /* keep entry in sys mailbox */
   MMARK = 1u<<5,       /* message is marked! */
   MODIFY = 1u<<6,      /* message has been modified */
   MNEW = 1u<<7,        /* message has never been seen */
   MREAD = 1u<<8,       /* message has been read sometime. */
   MSTATUS = 1u<<9,     /* message status has changed */
   MBOX = 1u<<10,       /* Send this to mbox, regardless */
   MNOFROM = 1u<<11,    /* no From line */
   MHIDDEN = 1u<<12,    /* message is hidden to user */
MFULLYCACHED = 1u<<13,  /* IMAP cached */
   MBOXED = 1u<<14,     /* message has been sent to mbox */
MUNLINKED = 1u<<15,     /* Unlinked from IMAP cache */
   MNEWEST = 1u<<16,    /* message is very new (newmail) */
   MFLAG = 1u<<17,      /* message has been flagged recently */
   MUNFLAG = 1u<<18,    /* message has been unflagged */
   MFLAGGED = 1u<<19,   /* message is `flagged' */
   MANSWER = 1u<<20,    /* message has been answered recently */
   MUNANSWER = 1u<<21,  /* message has been unanswered */
   MANSWERED = 1u<<22,  /* message is `answered' */
   MDRAFT = 1u<<23,     /* message has been drafted recently */
   MUNDRAFT = 1u<<24,   /* message has been undrafted */
   MDRAFTED = 1u<<25,   /* message is marked as `draft' */
   MOLDMARK = 1u<<26,   /* messages was marked previously */
   MSPAM = 1u<<27,      /* message is classified as spam */
   MSPAMUNSURE = 1u<<28  /* message may be spam, but it is unsure */
};
#define MMNORM          (MDELETED | MSAVED | MHIDDEN)
#define MMNDEL          (MDELETED | MHIDDEN)

#define visible(mp)     (((mp)->m_flag & MMNDEL) == 0)

struct mimepart {
   enum mflag  m_flag;
   enum content_info m_content_info;
#ifdef HAVE_SPAM
   ui32_t      m_spamscore;   /* Spam score as int, 24:8 bits */
#endif
   int         m_block;       /* block number of this part */
   size_t      m_offset;      /* offset in block of part */
   size_t      m_size;        /* Bytes in the part */
   size_t      m_xsize;       /* Bytes in the full part */
   long        m_lines;       /* Lines in the message: write format! */
   long        m_xlines;      /* Lines in the full message; ditto */
   time_t      m_time;        /* time the message was sent */
   char const  *m_from;       /* message sender */
   struct mimepart *m_nextpart;     /* next part at same level */
   struct mimepart *m_multipart;    /* parts of multipart */
   struct mimepart *m_parent;       /* enclosing multipart part */
   char const  *m_ct_type;          /* content-type */
   char const  *m_ct_type_plain;    /* content-type without specs */
   char const  *m_ct_type_usr_ovwr; /* Forcefully overwritten one */
   char const  *m_charset;
   char const  *m_ct_enc;           /* Content-Transfer-Encoding */
   enum mimecontent m_mimecontent;  /* ..in enum */
   enum mime_enc m_mime_enc;        /* ..in enum */
   char        *m_partstring;       /* Part level string */
   char        *m_filename;         /* ..of attachment */
   char const  *m_content_description;
   char const *m_external_body_url; /* message/external-body: access-type=URL */
   struct mime_handler *m_handler;  /* MIME handler if yet classified */
};

struct message {
   enum mflag  m_flag;        /* flags */
   enum content_info m_content_info;
#ifdef HAVE_SPAM
   ui32_t      m_spamscore;   /* Spam score as int, 24:8 bits */
#endif
   int         m_block;       /* block number of this message */
   size_t      m_offset;      /* offset in block of message */
   size_t      m_size;        /* Bytes in the message */
   size_t      m_xsize;       /* Bytes in the full message */
   long        m_lines;       /* Lines in the message */
   long        m_xlines;      /* Lines in the full message */
   time_t      m_time;        /* time the message was sent */
   time_t      m_date;        /* time in the 'Date' field */
   unsigned    m_idhash;      /* hash on Message-ID for threads */
   struct message *m_child;   /* first child of this message */
   struct message *m_younger; /* younger brother of this message */
   struct message *m_elder;   /* elder brother of this message */
   struct message *m_parent;  /* parent of this message */
   unsigned    m_level;       /* thread level of message */
   long        m_threadpos;   /* position in threaded display */
#ifdef HAVE_IMAP
   unsigned long m_uid;       /* IMAP unique identifier */
#endif
   char const  *m_maildir_file;  /* original maildir file of msg */
   ui32_t      m_maildir_hash;   /* hash of file name in maildir sub */
   int         m_collapsed;      /* collapsed thread information */
};

/* Given a file address, determine the block number it represents */
#define mailx_blockof(off)                ((int) ((off) / 4096))
#define mailx_offsetof(off)               ((int) ((off) % 4096))
#define mailx_positionof(block, offset)   ((off_t)(block) * 4096 + (offset))

enum gfield{ /* TODO -> enum m_grab_head, m_GH_xy */
   GNONE,
   GTO = 1u<<0,         /* Grab To: line */
   GSUBJECT = 1u<<1,    /* Likewise, Subject: line */
   GCC = 1u<<2,         /* And the Cc: line */
   GBCC = 1u<<3,        /* And also the Bcc: line */

   GNL = 1u<<4,         /* Print blank line after */
   GDEL = 1u<<5,        /* Entity removed from list */
   GCOMMA = 1u<<6,      /* detract() puts in commas */
   GUA = 1u<<7,         /* User-Agent field */
   GMIME = 1u<<8,       /* MIME 1.0 fields */
   GMSGID = 1u<<9,      /* a Message-ID */
   GNAMEONLY = 1u<<10,  /* detract() does NOT use fullnames */

   GIDENT = 1u<<11,     /* From:, Reply-To:, MFT: (user headers) */
   GREF = 1u<<12,       /* References:, In-Reply-To:, (Message-ID:) */
   GDATE = 1u<<13,      /* Date: field */
   GFULL = 1u<<14,      /* Include full names, comments etc. */
   GSKIN = 1u<<15,      /* Skin names */
   GEXTRA = 1u<<16,     /* Extra fields (mostly like GIDENT XXX) */
   GFILES = 1u<<17,     /* Include filename and pipe addresses */
   GFULLEXTRA = 1u<<18  /* Only with GFULL: GFULL less address */
};
#define GMASK           (GTO | GSUBJECT | GCC | GBCC)

enum header_flags {
   HF_NONE        = 0,
   HF_LIST_REPLY  = 1<< 0,
   HF_MFT_SENDER  = 1<< 1,    /* Add ourselves to Mail-Followup-To: */
   HF_RECIPIENT_RECORD = 1<<10, /* Save message in file named after rec. */
   HF__NEXT_SHIFT = 11
};

/* Structure used to pass about the current state of a message (header) */
struct n_header_field{
   struct n_header_field *hf_next;
   ui32_t hf_nl;              /* Field-name length */
   ui32_t hf_bl;              /* Field-body length*/
   char hf_dat[n_VFIELD_SIZE(0)];
};

struct header {
   ui32_t      h_flags;       /* enum header_flags bits */
   ui32_t      h_dummy;
   char        *h_subject;    /* Subject string */
   char const  *h_charset;    /* preferred charset */
   struct name *h_from;       /* overridden "From:" field */
   struct name *h_sender;     /* overridden "Sender:" field */
   struct name *h_to;         /* Dynamic "To:" string */
   struct name *h_cc;         /* Carbon copies string */
   struct name *h_bcc;        /* Blind carbon copies */
   struct name *h_ref;        /* References (possibly overridden) */
   struct attachment *h_attach; /* MIME attachments */
   struct name *h_reply_to;   /* overridden "Reply-To:" field */
   struct name *h_message_id; /* overridden "Message-ID:" field */
   struct name *h_in_reply_to;/* overridden "In-Reply-To:" field */
   struct name *h_mft;        /* Mail-Followup-To */
   char const  *h_list_post;  /* Address from List-Post:, for `Lreply' */
   struct n_header_field *h_user_headers;
   struct n_header_field *h_custom_headers; /* (Cached result) */
   /* Raw/original versions of the header(s). If any */
   char const *h_mailx_command;
   struct name *h_mailx_raw_to;
   struct name *h_mailx_raw_cc;
   struct name *h_mailx_raw_bcc;
   struct name *h_mailx_orig_from;
   struct name *h_mailx_orig_to;
   struct name *h_mailx_orig_cc;
   struct name *h_mailx_orig_bcc;
};

/* Handling of namelist nodes used in processing the recipients of mail and
 * aliases, inspection of mail-addresses and all that kind of stuff */
enum nameflags {
   NAME_NAME_SALLOC = 1u<<0,        /* .n_name is doped */
   NAME_FULLNAME_SALLOC = 1u<<1,    /* .n_fullname is doped */
   NAME_SKINNED = 1u<<2,            /* Is actually skin()ned */
   NAME_IDNA = 1u<<3,               /* IDNA was applied */

   NAME_ADDRSPEC_CHECKED = 1u<<4,   /* Address has been .. and */
   NAME_ADDRSPEC_ISFILE = 1u<<5,    /* ..is a file path */
   NAME_ADDRSPEC_ISPIPE = 1u<<6,    /* ..is a command for piping */
   NAME_ADDRSPEC_ISFILEORPIPE = NAME_ADDRSPEC_ISFILE | NAME_ADDRSPEC_ISPIPE,
   NAME_ADDRSPEC_ISNAME = 1u<<7,    /* ..is an alias name */
   NAME_ADDRSPEC_ISADDR = 1u<<8,    /* ..is a mail network address */

   NAME_ADDRSPEC_ERR_EMPTY = 1u<<9, /* An empty string (or NULL) */
   NAME_ADDRSPEC_ERR_ATSEQ = 1u<<10, /* Weird @ sequence */
   NAME_ADDRSPEC_ERR_CHAR = 1u<<11, /* Invalid character */
   NAME_ADDRSPEC_ERR_IDNA = 1u<<12, /* IDNA convertion failed */
   NAME_ADDRSPEC_ERR_NAME = 1u<<13, /* Alias with invalid content */
   NAME_ADDRSPEC_INVALID = NAME_ADDRSPEC_ERR_EMPTY |
         NAME_ADDRSPEC_ERR_ATSEQ | NAME_ADDRSPEC_ERR_CHAR |
         NAME_ADDRSPEC_ERR_IDNA | NAME_ADDRSPEC_ERR_NAME,

   /* Error storage (we must fit in 31-bit) */
   _NAME_SHIFTWC = 14,
   _NAME_MAXWC = 0x1FFFF,
   _NAME_MASKWC = _NAME_MAXWC << _NAME_SHIFTWC
   /* Bit 31 (32) == SI32_MIN temporarily used */
};

/* In the !_ERR_EMPTY case, the failing character can be queried */
#define NAME_ADDRSPEC_ERR_GETWC(F)  \
   ((((unsigned int)(F) & _NAME_MASKWC) >> _NAME_SHIFTWC) & _NAME_MAXWC)
#define NAME_ADDRSPEC_ERR_SET(F, E, WC) \
do {\
   (F) = ((F) & ~(NAME_ADDRSPEC_INVALID | _NAME_MASKWC)) |\
         (E) | (((unsigned int)(WC) & _NAME_MAXWC) << _NAME_SHIFTWC);\
} while (0)

struct name{
   struct name *n_flink;   /* Forward link in list. */
   struct name *n_blink;   /* Backward list link */
   enum gfield n_type;     /* From which list it came */
   ui32_t n_flags;         /* enum nameflags */
   char *n_name;           /* This fella's address */
   char *n_fullname;       /* Ditto, unless GFULL including comment */
   char *n_fullextra;      /* GFULL, without address */
};

struct n_addrguts{
   /* Input string as given (maybe replaced with a fixed one!) */
   char const *ag_input;
   size_t ag_ilen;            /* strlen() of input */
   size_t ag_iaddr_start;     /* Start of *addr-spec* in .ag_input */
   size_t ag_iaddr_aend;      /* ..and one past its end */
   char *ag_skinned;          /* Output (alloced if !=.ag_input) */
   size_t ag_slen;            /* strlen() of .ag_skinned */
   size_t ag_sdom_start;      /* Start of domain in .ag_skinned, */
   enum nameflags ag_n_flags; /* enum nameflags of .ag_skinned */
};

/* MIME attachments */
enum attach_conv {
   AC_DEFAULT,       /* _get_lc() -> _iter_*() */
   AC_FIX_INCS,      /* "charset=".a_input_charset (nocnv) */
   AC_TMPFILE        /* attachment.a_tmpf is converted */
};

enum n_attach_error{
   n_ATTACH_ERR_NONE,
   n_ATTACH_ERR_FILE_OPEN,
   n_ATTACH_ERR_ICONV_FAILED,
   n_ATTACH_ERR_ICONV_NAVAIL,
   n_ATTACH_ERR_OTHER
};

struct attachment {
   struct attachment *a_flink; /* Forward link in list. */
   struct attachment *a_blink; /* Backward list link */
   char const  *a_path_user;  /* Path as given (maybe including iconv spec) */
   char const  *a_path;       /* Path as opened */
   char const  *a_path_bname; /* Basename of path as opened */
   char const  *a_name;       /* File name to be stored (EQ a_path_bname) */
   char const  *a_content_type;  /* content type */
   char const  *a_content_disposition; /* content disposition */
   struct name *a_content_id; /* content id */
   char const  *a_content_description; /* content description */
   char const  *a_input_charset; /* Interpretation depends on .a_conv */
   char const  *a_charset;    /* ... */
   FILE        *a_tmpf;       /* If AC_TMPFILE */
   enum attach_conv a_conv;   /* User chosen conversion */
   int         a_msgno;       /* message number */
};

struct sendbundle {
   struct header  *sb_hp;
   struct name    *sb_to;
   FILE           *sb_input;
   struct str     sb_signer;  /* USER@HOST for signing+ */
   struct url     sb_url;
   struct ccred   sb_ccred;
};

/* For saving the current directory and later returning */
struct cw {
#ifdef HAVE_FCHDIR
   int         cw_fd;
#else
   char        cw_wd[PATH_MAX];
#endif
};

/*
 * Global variable declarations
 *
 * These become instantiated in main.c.
 */

#undef VL
#ifdef n_MAIN_SOURCE
# ifndef HAVE_AMALGAMATION
#  define VL
# else
#  define VL static
# endif
#else
# define VL extern
#endif

#ifndef HAVE_AMALGAMATION
VL char const n_month_names[12 + 1][4];
VL char const n_weekday_names[7 + 1][4];

VL char const n_uagent[sizeof VAL_UAGENT];
VL char const n_error[sizeof n_ERROR];
VL char const n_path_devnull[sizeof n_PATH_DEVNULL];
VL char const n_reproducible_name[sizeof "reproducible_build"];
VL char const n_unirepl[sizeof n_UNIREPL];
VL char const n_empty[1];
VL char const n_0[2];
VL char const n_1[2];
VL char const n_m1[3];     /* -1 */
VL char const n_qm[2];     /* Question-mark ? */
VL char const n_em[2];     /* Exclamation-mark ! */
VL char const n_star[2];   /* Asterisk * */
VL char const n_at[2];     /* Commercial at @ */
VL char const n_ns[2];     /* Number sign # */
VL ui16_t const n_class_char[1 + 0x7F];
#endif

VL FILE *n_stdin;
VL FILE *n_stdout;
VL FILE *n_stderr;
VL FILE *n_tty_fp;               /* Our terminal output TODO input channel */
VL void *n_readctl_overlay;      /* `readctl' overlay (see c_readctl()) */

VL ui32_t n_mb_cur_max;          /* Value of MB_CUR_MAX */
VL ui32_t n_realscreenheight;    /* The real screen height */
VL ui32_t n_scrnwidth;           /* Screen width/guess; also n_SCRNWIDTH_LIST */
VL ui32_t n_scrnheight;          /* Screen height/guess (for header summary+) */

VL char const *n_progname;       /* Our name */

VL gid_t n_group_id;             /* getgid() and getuid() */
VL uid_t n_user_id;
VL pid_t n_pid;                  /* getpid() (lazy initialized) */

VL int n_exit_status;            /* Program exit status TODO long term: ex_no */
VL ui32_t n_poption;             /* Bits of enum n_program_option */
VL char const *n_poption_arg_Mm; /* Argument for -[Mm] aka n_PO_[Mm]_FLAG */
VL struct name *n_poption_arg_r; /* Argument to -r option */
VL char const **n_smopts;        /* MTA options from command line */
VL size_t n_smopts_cnt;          /* Entries in n_smopts */

/* The current execution data context */
VL struct n_go_data_ctx *n_go_data;
VL ui32_t n_psonce;              /* Bits of enum n_program_state_once */
VL ui32_t n_pstate;              /* Bits of enum n_program_state */
/* TODO "cmd_tab.h ARG_EM set"-storage (n_[01..]) as long as we don't have a
 * TODO struct CmdCtx where each command has its own ARGC/ARGV, errno and exit
 * TODO status and may-place-in-history bit, need to manage a global bypass.. */
VL si32_t n_pstate_err_no;       /* What backs $! n_ERR_* TODO ..HACK */
VL si32_t n_pstate_ex_no;        /* What backs $? n_EX_* TODO ..HACK ->64-bit */
#define n_err_no errno           /* Don't use errno directly, for later XXX */
VL si32_t n_iconv_err_no;        /* TODO HACK: part of CTX to not get lost */

/* XXX stylish sorting */
VL int            msgCount;            /* Count of messages read in */
VL struct mailbox mb;                  /* Current mailbox */
VL char           mailname[PATH_MAX];  /* Name of current file TODO URL/object*/
VL char           displayname[80 - 16]; /* Prettyfied for display TODO URL/obj*/
VL char           prevfile[PATH_MAX];  /* Name of previous file TODO URL/obj */
VL off_t          mailsize;            /* Size of system mailbox */
VL struct message *dot;                /* Pointer to current message */
VL struct message *prevdot;            /* Previous current message */
VL struct message *message;            /* The actual message structure */
VL struct message *threadroot;         /* first threaded message */
VL int            *n_msgvec;           /* Folder setmsize(), list.c res. store*/
#ifdef HAVE_IMAP
VL int            imap_created_mailbox; /* hack to get feedback from imap */
#endif

VL struct time_current  time_current;  /* time(3); send: mail1() XXXcarrier */
VL struct termios_state termios_state; /* getpassword(); see commands().. */

#ifdef HAVE_SSL
VL enum ssl_verify_level   ssl_verify_level; /* SSL verification level */
#endif

#ifdef HAVE_ICONV
VL iconv_t     iconvd;
#endif

VL volatile int interrupts; /* TODO rid! */
VL sighandler_type dflpipe;

/*
 * Finally, let's include the function prototypes XXX embed
 */

#ifndef n_PRIVSEP_SOURCE
# include "nailfuns.h"
#endif

#endif /* n_NAIL_H */
/* s-it-mode */