nand_base: We have to ignore the -EUCLEAN error

[barebox-mini2440.git] / common / hush.c

/* vi: set sw=8 ts=8: */
/*
 * hush.c -- a prototype Bourne shell grammar parser
 *      Intended to follow the original Thompson and Ritchie
 *      "small and simple is beautiful" philosophy, which
 *      incidentally is a good match to today's BusyBox.
 *
 * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
 *
 * Credits:
 *      The parser routines proper are all original material, first
 *      written Dec 2000 and Jan 2001 by Larry Doolittle.
 *      The execution engine, the builtins, and much of the underlying
 *      support has been adapted from busybox-0.49pre's lash,
 *      which is Copyright (C) 2000 by Lineo, Inc., and
 *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
 *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
 *      Erik W. Troan, which they placed in the public domain.  I don't know
 *      how much of the Johnson/Troan code has survived the repeated rewrites.
 * Other credits:
 *      simple_itoa() was lifted from boa-0.93.15
 *      b_addchr() derived from similar w_addchar function in glibc-2.2
 *      setup_redirect(), redirect_opt_num(), and big chunks of main()
 *        and many builtins derived from contributions by Erik Andersen
 *      miscellaneous bugfixes from Matt Kraai
 */

/** @page shell_notes Simple Shell Environment: Hush
 *
 * @par Notes from the source:
 *
 * Intended to follow the original Thompson and Ritchie "small and simple
 * is beautiful" philosophy, which incidentally is a good match to
 * today's BusyBox.
 *
 * There are two big (and related) architecture differences between
 * this parser and the lash parser.  One is that this version is
 * actually designed from the ground up to understand nearly all
 * of the Bourne grammar.  The second, consequential change is that
 * the parser and input reader have been turned inside out.  Now,
 * the parser is in control, and asks for input as needed.  The old
 * way had the input reader in control, and it asked for parsing to
 * take place as needed.  The new way makes it much easier to properly
 * handle the recursion implicit in the various substitutions, especially
 * across continuation lines.
 *
 * Bash grammar not implemented: (how many of these were in original sh?)
 * -     $@ (those sure look like weird quoting rules)
 * -     $_
 * -     ! negation operator for pipes
 * -     &> and >& redirection of stdout+stderr
 * -     Brace Expansion
 * -     Tilde Expansion
 * -     fancy forms of Parameter Expansion
 * -     aliases
 * -     Arithmetic Expansion
 * -     <(list) and >(list) Process Substitution
 * -     reserved words: case, esac, select, function
 * -     Here Documents ( << word )
 * -     Functions
 *
 * Major bugs:
 * -     job handling woefully incomplete and buggy
 * -     reserved word execution woefully incomplete and buggy
 *
 * to-do:
 * -     port selected bugfixes from post-0.49 busybox lash - done?
 * -     finish implementing reserved words: for, while, until, do, done
 * -     change { and } from special chars to reserved words
 * -     builtins: break, continue, eval, return, set, trap, ulimit
 * -     test magic exec
 * -     handle children going into background
 * -     clean up recognition of null pipes
 * -     check setting of global_argc and global_argv
 * -     control-C handling, probably with longjmp
 * -     follow IFS rules more precisely, including update semantics
 * -     figure out what to do with backslash-newline
 * -     explain why we use signal instead of sigaction
 * -     propagate syntax errors, die on resource errors?
 * -     continuation lines, both explicit and implicit - done?
 * -     memory leak finding and plugging - done?
 * -     more testing, especially quoting rules and redirection
 * -     document how quoting rules not precisely followed for variable assignments
 * -     maybe change map[] to use 2-bit entries
 * -     (eventually) remove all the printf's
 *
 * Things that do _not_ work in this environment:
 *
 * - redirecting (stdout to a file for example)
 * - recursion
 *
 * Enable the "Hush parser" in "General Settings", "Select your shell" to
 * get the new console feeling.
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <malloc.h>         /* malloc, free, realloc*/
#include <xfuncs.h>
#include <linux/ctype.h>    /* isalpha, isdigit */
#include <common.h>        /* readline */
#include <hush.h>
#include <environment.h>
#include <command.h>        /* find_cmd */
#include <driver.h>
#include <errno.h>
#include <fs.h>
#include <libbb.h>
#include <glob.h>

/*cmd_boot.c*/
extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);      /* do_bootd */
#define SPECIAL_VAR_SYMBOL 03


#define EXIT_SUCCESS 0
#define EOF -1
#define syntax() syntax_err()
#define xstrdup strdup
#define error_msg printf

typedef enum {
        PIPE_SEQ = 1,
        PIPE_AND = 2,
        PIPE_OR  = 3,
        PIPE_BG  = 4,
} pipe_style;

/* might eventually control execution */
typedef enum {
        RES_NONE  = 0,
        RES_IF    = 1,
        RES_THEN  = 2,
        RES_ELIF  = 3,
        RES_ELSE  = 4,
        RES_FI    = 5,
        RES_FOR   = 6,
        RES_WHILE = 7,
        RES_UNTIL = 8,
        RES_DO    = 9,
        RES_DONE  = 10,
        RES_XXXX  = 11,
        RES_IN    = 12,
        RES_SNTX  = 13
} reserved_style;
#define FLAG_END   (1<<RES_NONE)
#define FLAG_IF    (1<<RES_IF)
#define FLAG_THEN  (1<<RES_THEN)
#define FLAG_ELIF  (1<<RES_ELIF)
#define FLAG_ELSE  (1<<RES_ELSE)
#define FLAG_FI    (1<<RES_FI)
#define FLAG_FOR   (1<<RES_FOR)
#define FLAG_WHILE (1<<RES_WHILE)
#define FLAG_UNTIL (1<<RES_UNTIL)
#define FLAG_DO    (1<<RES_DO)
#define FLAG_DONE  (1<<RES_DONE)
#define FLAG_IN    (1<<RES_IN)
#define FLAG_START (1<<RES_XXXX)

/* This holds pointers to the various results of parsing */
struct p_context {
        struct child_prog *child;
        struct pipe *list_head;
        struct pipe *pipe;
        reserved_style w;
        int old_flag;                           /* for figuring out valid reserved words */
        struct p_context *stack;
        int type;                       /* define type of parser : ";$" common or special symbol */
        /* How about quoting status? */

        char **global_argv;
        unsigned int global_argc;
};


struct child_prog {
        char **argv;                            /* program name and arguments */
        int    argc;                            /* number of program arguments */
        struct pipe *group;                     /* if non-NULL, first in group or subshell */
        int sp;                         /* number of SPECIAL_VAR_SYMBOL */
        int type;
        glob_t glob_result;                     /* result of parameter globbing */
};

struct pipe {
        int num_progs;                          /* total number of programs in job */
        struct child_prog *progs;       /* array of commands in pipe */
        struct pipe *next;                      /* to track background commands */
        pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
        reserved_style r_mode;          /* supports if, for, while, until */
};


static char console_buffer[CONFIG_CBSIZE];              /* console I/O buffer   */

/* globals, connect us to the outside world
 * the first three support $?, $#, and $1 */
static unsigned int last_return_code;

/* "globals" within this file */
static uchar *ifs;
static char map[256];

#define B_CHUNK (100)
#define B_NOSPAC 1

typedef struct {
        char *data;
        int length;
        int maxlen;
        int quote;
        int nonnull;
} o_string;
#define NULL_O_STRING {NULL,0,0,0,0}
/* used for initialization:
        o_string foo = NULL_O_STRING; */

/* I can almost use ordinary FILE *.  Is open_memstream() universally
 * available?  Where is it documented? */
struct in_str {
        const char *p;
        int __promptme;
        int promptmode;
        int (*get) (struct in_str *);
        int (*peek) (struct in_str *);
};
#define b_getch(input) ((input)->get(input))
#define b_peek(input) ((input)->peek(input))


#define final_printf debug

static void syntax_err(void) {
         printf("syntax error\n");
}

/*   o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
static void b_reset(o_string *o);
static int b_addqchr(o_string *o, int ch, int quote);
/*  in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
static int file_get(struct in_str *i);
static int file_peek(struct in_str *i);
static void setup_file_in_str(struct in_str *i);
static void setup_string_in_str(struct in_str *i, const char *s);
/*  "run" the final data structures: */
static int free_pipe_list(struct pipe *head, int indent);
static int free_pipe(struct pipe *pi, int indent);
/*  really run the final data structures: */
static int run_list_real(struct pipe *pi);
static int run_pipe_real(struct pipe *pi);
/*   extended glob support: */
/*   variable assignment: */
static int is_assignment(const char *s);
/*   data structure manipulation: */
static void initialize_context(struct p_context *ctx);
static int done_word(o_string *dest, struct p_context *ctx);
static int done_command(struct p_context *ctx);
static int done_pipe(struct p_context *ctx, pipe_style type);
/*   primary string parsing: */
static const char *lookup_param(char *src);
static char *make_string(char **inp);
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
/*   setup: */
static int parse_stream_outer(struct p_context *ctx, struct in_str *inp, int flag);

static int parse_string_outer(struct p_context *ctx, const char *s, int flag);
/*     local variable support */
static char **make_list_in(char **inp, char *name);
static char *insert_var_value(char *inp);
static int set_local_var(const char *s, int flg_export);
static int execute_script(const char *path, int argc, char *argv[]);
static int source_script(const char *path, int argc, char *argv[]);

static int b_check_space(o_string *o, int len)
{
        /* It would be easy to drop a more restrictive policy
         * in here, such as setting a maximum string length */
        if (o->length + len > o->maxlen) {
                char *old_data = o->data;
                /* assert (data == NULL || o->maxlen != 0); */
                o->maxlen += max(2*len, B_CHUNK);
                o->data = realloc(o->data, 1 + o->maxlen);
                if (o->data == NULL) {
                        free(old_data);
                }
        }
        return o->data == NULL;
}

static int b_addchr(o_string *o, int ch)
{
        debug("b_addchr: %c %d %p\n", ch, o->length, o);
        if (b_check_space(o, 1))
                return B_NOSPAC;
        o->data[o->length] = ch;
        o->length++;
        o->data[o->length] = '\0';
        return 0;
}

static void b_reset(o_string *o)
{
        o->length = 0;
        o->nonnull = 0;
        if (o->data != NULL) *o->data = '\0';
}

static void b_free(o_string *o)
{
        b_reset(o);
        free(o->data);
        o->data = NULL;
        o->maxlen = 0;
}

/* My analysis of quoting semantics tells me that state information
 * is associated with a destination, not a source.
 */
static int b_addqchr(o_string *o, int ch, int quote)
{
        if (quote && strchr("*?[",ch)) {
                int rc;
                rc = b_addchr(o, '\\');
                if (rc)
                        return rc;
        }
        return b_addchr(o, ch);
}

/* belongs in utility.c */
char *simple_itoa(unsigned int i)
{
        /* 21 digits plus null terminator, good for 64-bit or smaller ints */
        static char local[22];
        char *p = &local[21];
        *p-- = '\0';
        do {
                *p-- = '0' + i % 10;
                i /= 10;
        } while (i > 0);
        return p + 1;
}

static int b_adduint(o_string *o, unsigned int i)
{
        int r;
        char *p = simple_itoa(i);
        /* no escape checking necessary */
        do {
                r=b_addchr(o, *p++);
        } while (r==0 && *p);

        return r;
}

static int static_get(struct in_str *i)
{
        int ch=*i->p++;
        if (ch=='\0')
                return EOF;
        return ch;
}


static int static_peek(struct in_str *i)
{
        return *i->p;
}


static char *getprompt(void)
{
        static char *prompt;

        if (!prompt)
                prompt = xmalloc(PATH_MAX + strlen(CONFIG_PROMPT) + 1);

        sprintf(prompt, "%s%s ", CONFIG_PROMPT, getcwd());
        return prompt;
}

static void get_user_input(struct in_str *i)
{
        int n;
        static char the_command[CONFIG_CBSIZE];

        i->__promptme = 1;
        if (i->promptmode == 1) {
                n = readline(getprompt(), console_buffer, CONFIG_CBSIZE);
        } else {
                n = readline(CONFIG_PROMPT_HUSH_PS2, console_buffer, CONFIG_CBSIZE);
        }
        if (n == -1 ) {
                i->__promptme = 0;
                n = 0;
        }

        console_buffer[n] = '\n';
        console_buffer[n+1]= '\0';
        if (i->promptmode == 1) {
                strcpy(the_command,console_buffer);
                i->p = the_command;
        } else {
                if (console_buffer[0] != '\n') {
                        if (strlen(the_command) + strlen(console_buffer)
                            < CONFIG_CBSIZE) {
                                n = strlen(the_command);
                                the_command[n-1] = ' ';
                                strcpy(&the_command[n],console_buffer);
                        }
                        else {
                                the_command[0] = '\n';
                                the_command[1] = '\0';
                        }
                }
                if (i->__promptme == 0) {
                        the_command[0] = '\n';
                        the_command[1] = '\0';
                }
                i->p = console_buffer;
        }
}

/* This is the magic location that prints prompts
 * and gets data back from the user */
static int file_get(struct in_str *i)
{
        int ch;

        ch = 0;
        /* If there is data waiting, eat it up */
        if (i->p && *i->p) {
                ch=*i->p++;
        } else {
                /* need to double check i->file because we might be doing something
                 * more complicated by now, like sourcing or substituting. */
                        while(! i->p  || strlen(i->p)==0 ) {
                                get_user_input(i);
                        }
                        i->promptmode=2;
                        if (i->p && *i->p) {
                                ch=*i->p++;
                        }
                debug("b_getch: got a %d\n", ch);
        }
        return ch;
}

/* All the callers guarantee this routine will never be
 * used right after a newline, so prompting is not needed.
 */
static int file_peek(struct in_str *i)
{
                return *i->p;
}

static void setup_file_in_str(struct in_str *i)
{
        i->peek = file_peek;
        i->get = file_get;
        i->__promptme=1;
        i->promptmode=1;
        i->p = NULL;
}

static void setup_string_in_str(struct in_str *i, const char *s)
{
        i->peek = static_peek;
        i->get = static_get;
        i->__promptme=1;
        i->promptmode=1;
        i->p = s;
}


/* run_pipe_real() starts all the jobs, but doesn't wait for anything
 * to finish.  See checkjobs().
 *
 * return code is normally -1, when the caller has to wait for children
 * to finish to determine the exit status of the pipe.  If the pipe
 * is a simple builtin command, however, the action is done by the
 * time run_pipe_real returns, and the exit code is provided as the
 * return value.
 *
 * The input of the pipe is always stdin, the output is always
 * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
 * because it tries to avoid running the command substitution in
 * subshell, when that is in fact necessary.  The subshell process
 * now has its stdout directed to the input of the appropriate pipe,
 * so this routine is noticeably simpler.
 */
static int run_pipe_real(struct pipe *pi)
{
        int i;
        int nextin;
        struct child_prog *child;
        cmd_tbl_t *cmdtp;
        char *p;
        char *path;
        int ret;
# if __GNUC__
        /* Avoid longjmp clobbering */
        (void) &i;
        (void) &nextin;
        (void) &child;
# endif

        nextin = 0;

        /* Check if this is a simple builtin (not part of a pipe).
         * Builtins within pipes have to fork anyway, and are handled in
         * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
         */
        if (pi->num_progs == 1)
                child = & (pi->progs[0]);
        if (pi->num_progs == 1 && child->group) {
                int rcode;
                debug("non-subshell grouping\n");
                rcode = run_list_real(child->group);
                return rcode;
        } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
                for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
                if (i!=0 && child->argv[i]==NULL) {
                        /* assignments, but no command: set the local environment */
                        for (i=0; child->argv[i]!=NULL; i++) {

                                /* Ok, this case is tricky.  We have to decide if this is a
                                 * local variable, or an already exported variable.  If it is
                                 * already exported, we have to export the new value.  If it is
                                 * not exported, we need only set this as a local variable.
                                 * This junk is all to decide whether or not to export this
                                 * variable. */
                                int export_me=0;
                                char *name, *value;
                                name = xstrdup(child->argv[i]);
                                debug("Local environment set: %s\n", name);
                                value = strchr(name, '=');
                                if (value)
                                        *value=0;
                                free(name);
                                p = insert_var_value(child->argv[i]);
                                set_local_var(p, export_me);
                                if (p != child->argv[i])
                                        free(p);
                        }
                        return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
                }
                for (i = 0; is_assignment(child->argv[i]); i++) {
                        p = insert_var_value(child->argv[i]);
                        set_local_var(p, 0);
                        if (p != child->argv[i]) {
                                child->sp--;
                                free(p);
                        }
                }
                if (child->sp) {
                        char * str = NULL;
                        struct p_context ctx;
                        str = make_string((child->argv + i));
                        parse_string_outer(&ctx, str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
                        free(str);
                        return last_return_code;
                }

                if (strchr(child->argv[i], '/')) {
                        return execute_script(child->argv[i], child->argc-i, &child->argv[i]);
                }
                if ((path = find_execable(child->argv[i]))) {
                        ret = execute_script(path, child->argc-i, &child->argv[i]);
                        free(path);
                        return ret;
                }
                /* Look up command in command table */
                if ((cmdtp = find_cmd(child->argv[i]))) {
                        int rcode;

                        /* found - check max args */
                        if ((child->argc - i) > cmdtp->maxargs) {
                                printf ("Usage:\n%s\n", cmdtp->usage);
                                return -1;
                        }
                        /* OK - call function to do the command */
                        rcode = cmdtp->cmd(cmdtp, child->argc-i, &child->argv[i]);

                        return rcode;
                } else {
                        printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
                        return -1;      /* give up after bad command */
                }
        }
        return -1;
}

static int run_list_real(struct pipe *pi)
{
        char *save_name = NULL;
        char **list = NULL;
        char **save_list = NULL;
        struct pipe *rpipe;
        int flag_rep = 0;
        int rcode=0, flag_skip=1;
        int flag_restore = 0;
        int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
        reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
        /* check syntax for "for" */
        for (rpipe = pi; rpipe; rpipe = rpipe->next) {
                if ((rpipe->r_mode == RES_IN ||
                    rpipe->r_mode == RES_FOR) &&
                    (rpipe->next == NULL)) {
                                syntax();
                                return 1;
                }
                if ((rpipe->r_mode == RES_IN &&
                        (rpipe->next->r_mode == RES_IN &&
                        rpipe->next->progs->argv != NULL))||
                        (rpipe->r_mode == RES_FOR &&
                        rpipe->next->r_mode != RES_IN)) {
                                syntax();
                                return 1;
                }
        }
        for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
                if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
                        pi->r_mode == RES_FOR) {
                                /* check Ctrl-C */
                                if (ctrlc())
                                        return 1;
                                flag_restore = 0;
                                if (!rpipe) {
                                        flag_rep = 0;
                                        rpipe = pi;
                                }
                }
                rmode = pi->r_mode;
                debug("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
                if (rmode == skip_more_in_this_rmode && flag_skip) {
                        if (pi->followup == PIPE_SEQ) flag_skip=0;
                        continue;
                }
                flag_skip = 1;
                skip_more_in_this_rmode = RES_XXXX;
                if (rmode == RES_THEN || rmode == RES_ELSE)
                        if_code = next_if_code;
                if (rmode == RES_THEN &&  if_code)
                        continue;
                if (rmode == RES_ELSE && !if_code)
                        continue;
                if (rmode == RES_ELIF && !if_code)
                        break;
                if (rmode == RES_FOR && pi->num_progs) {
                        if (!list) {
                                /* if no variable values after "in" we skip "for" */
                                if (!pi->next->progs->argv)
                                        continue;
                                /* create list of variable values */
                                list = make_list_in(pi->next->progs->argv,
                                        pi->progs->argv[0]);
                                save_list = list;
                                save_name = pi->progs->argv[0];
                                pi->progs->argv[0] = NULL;
                                flag_rep = 1;
                        }
                        if (!(*list)) {
                                free(pi->progs->argv[0]);
                                free(save_list);
                                list = NULL;
                                flag_rep = 0;
                                pi->progs->argv[0] = save_name;
                                continue;
                        } else {
                                /* insert new value from list for variable */
                                if (pi->progs->argv[0])
                                        free(pi->progs->argv[0]);
                                pi->progs->argv[0] = *list++;
                        }
                }
                if (rmode == RES_IN)
                        continue;
                if (rmode == RES_DO) {
                        if (!flag_rep)
                                continue;
                }
                if ((rmode == RES_DONE)) {
                        if (flag_rep) {
                                flag_restore = 1;
                        } else {
                                rpipe = NULL;
                        }
                }
                if (pi->num_progs == 0)
                        continue;
                rcode = run_pipe_real(pi);
                debug("run_pipe_real returned %d\n",rcode);
                if (rcode < -1) {
                        last_return_code = -rcode - 2;
                        return -2;      /* exit */
                }
                last_return_code=rcode;
                if ( rmode == RES_IF || rmode == RES_ELIF )
                        next_if_code=rcode;  /* can be overwritten a number of times */
                if (rmode == RES_WHILE)
                        flag_rep = !last_return_code;
                if (rmode == RES_UNTIL)
                        flag_rep = last_return_code;
                if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
                     (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
                        skip_more_in_this_rmode=rmode;
        }
        return rcode;
}

#ifdef DEBUG
/* broken, of course, but OK for testing */
static char *indenter(int i)
{
        static char blanks[]="                                    ";
        return &blanks[sizeof(blanks)-i-1];
}
#endif

/* return code is the exit status of the pipe */
static int free_pipe(struct pipe *pi, int indent)
{
        char **p;
        struct child_prog *child;
        int a, i, ret_code=0;

        for (i=0; i<pi->num_progs; i++) {
                child = &pi->progs[i];
                final_printf("%s  command %d:\n",indenter(indent),i);
                if (child->argv) {
                        for (a=0,p=child->argv; *p; a++,p++) {
                                final_printf("%s   argv[%d] = %s\n",indenter(indent),a,*p);
                        }
                        globfree(&child->glob_result);
                        child->argv=NULL;
                } else if (child->group) {
                        ret_code = free_pipe_list(child->group,indent+3);
                        final_printf("%s   end group\n",indenter(indent));
                } else {
                        final_printf("%s   (nil)\n",indenter(indent));
                }
        }
        free(pi->progs);   /* children are an array, they get freed all at once */
        pi->progs=NULL;
        return ret_code;
}

static int free_pipe_list(struct pipe *head, int indent)
{
        int rcode=0;   /* if list has no members */
        struct pipe *pi, *next;
        for (pi=head; pi; pi=next) {
                final_printf("%s pipe reserved mode %d\n", indenter(indent), pi->r_mode);
                rcode = free_pipe(pi, indent);
                final_printf("%s pipe followup code %d\n", indenter(indent), pi->followup);
                next=pi->next;
                pi->next=NULL;
                free(pi);
        }
        return rcode;
}

/* The API for glob is arguably broken.  This routine pushes a non-matching
 * string into the output structure, removing non-backslashed backslashes.
 * If someone can prove me wrong, by performing this function within the
 * original glob(3) api, feel free to rewrite this routine into oblivion.
 * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
 * XXX broken if the last character is '\\', check that before calling.
 */
static int globhack(const char *src, int flags, glob_t *pglob)
{
        int cnt=0, pathc;
        const char *s;
        char *dest;
        for (cnt=1, s=src; s && *s; s++) {
                if (*s == '\\') s++;
                cnt++;
        }
        dest = xmalloc(cnt);
        if (!(flags & GLOB_APPEND)) {
                pglob->gl_pathv = NULL;
                pglob->gl_pathc = 0;
                pglob->gl_offs = 0;
        }
        pathc = ++pglob->gl_pathc;
        pglob->gl_pathv = xrealloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
        pglob->gl_pathv[pathc-1] = dest;
        pglob->gl_pathv[pathc] = NULL;
        for (s=src; s && *s; s++, dest++) {
                if (*s == '\\') s++;
                *dest = *s;
        }
        *dest='\0';
        return 0;
}

/* XXX broken if the last character is '\\', check that before calling */
static int glob_needed(const char *s)
{
#ifdef CONFIG_GLOB
        for (; *s; s++) {
                if (*s == '\\') s++;
                if (strchr("*[?",*s))
                        return 1;
        }
#endif
        return 0;
}

static int xglob(o_string *dest, int flags, glob_t *pglob)
{
        int gr;

        /* short-circuit for null word */
        /* we can code this better when the debug's are gone */
        if (dest->length == 0) {
                if (dest->nonnull) {
                        /* bash man page calls this an "explicit" null */
                        gr = globhack(dest->data, flags, pglob);
                        debug("globhack returned %d\n",gr);
                } else {
                        return 0;
                }
        } else if (glob_needed(dest->data)) {
                gr = glob(dest->data, flags, NULL, pglob);
                debug("glob returned %d\n",gr);
                if (gr == GLOB_NOMATCH) {
                        /* quote removal, or more accurately, backslash removal */
                        gr = globhack(dest->data, flags, pglob);
                        debug("globhack returned %d\n",gr);
                }
        } else {
                gr = globhack(dest->data, flags, pglob);
                debug("globhack returned %d\n",gr);
        }
        if (gr != 0) { /* GLOB_ABORTED ? */
                error_msg("glob(3) error %d",gr);
        }
        /* globprint(glob_target); */
        return gr;
}

/* Select which version we will use */
static int run_list(struct pipe *pi)
{
        int rcode = 0;

        rcode = run_list_real(pi);

        /* free_pipe_list has the side effect of clearing memory
         * In the long run that function can be merged with run_list_real,
         * but doing that now would hobble the debugging effort. */
        free_pipe_list(pi,0);
        return rcode;
}

static char *get_dollar_var(char ch);

/* This is used to set local shell variables
   flg_export==0 if only local (not exporting) variable
   flg_export==1 if "new" exporting environ
   flg_export>1  if current startup environ (not call putenv()) */
static int set_local_var(const char *s, int flg_export)
{
        char *name, *value;
        int ret;

        /* might be possible! */
        if (!isalpha(*s))
                return -1;

        name = strdup(s);

        /* Assume when we enter this function that we are already in
         * NAME=VALUE format.  So the first order of business is to
         * split 's' on the '=' into 'name' and 'value' */
        value = strchr(name, '=');
        if (value==0 && ++value==0) {
                free(name);
                return -1;
        }
        *value++ = 0;

        ret = setenv(name, value);
        free(name);

        return ret;
}



static int is_assignment(const char *s)
{
        if (s == NULL)
                return 0;

        if (!isalpha(*s))
                return 0;
        ++s;
        while(isalnum(*s) || *s=='_' || *s=='.')
                ++s;
        return *s=='=';
}


static struct pipe *new_pipe(void) {
        return (struct pipe *)xzalloc(sizeof(struct pipe));
}

static void initialize_context(struct p_context *ctx)
{
        ctx->pipe=NULL;
        ctx->child=NULL;
        ctx->list_head=new_pipe();
        ctx->pipe=ctx->list_head;
        ctx->w=RES_NONE;
        ctx->stack=NULL;
        ctx->old_flag=0;
        done_command(ctx);   /* creates the memory for working child */
}

/* normal return is 0
 * if a reserved word is found, and processed, return 1
 * should handle if, then, elif, else, fi, for, while, until, do, done.
 * case, function, and select are obnoxious, save those for later.
 */
struct reserved_combo {
        char *literal;
        int code;
        long flag;
};
/* Mostly a list of accepted follow-up reserved words.
 * FLAG_END means we are done with the sequence, and are ready
 * to turn the compound list into a command.
 * FLAG_START means the word must start a new compound list.
 */
static struct reserved_combo reserved_list[] = {
        { "if",    RES_IF,    FLAG_THEN | FLAG_START },
        { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
        { "elif",  RES_ELIF,  FLAG_THEN },
        { "else",  RES_ELSE,  FLAG_FI   },
        { "fi",    RES_FI,    FLAG_END  },
        { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
        { "while", RES_WHILE, FLAG_DO   | FLAG_START },
        { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
        { "in",    RES_IN,    FLAG_DO   },
        { "do",    RES_DO,    FLAG_DONE },
        { "done",  RES_DONE,  FLAG_END  }
};
#define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))

static int reserved_word(o_string *dest, struct p_context *ctx)
{
        struct reserved_combo *r;
        for (r=reserved_list;
                r<reserved_list+NRES; r++) {
                if (strcmp(dest->data, r->literal) == 0) {
                        debug("found reserved word %s, code %d\n",r->literal,r->code);
                        if (r->flag & FLAG_START) {
                                struct p_context *new = xmalloc(sizeof(struct p_context));
                                debug("push stack\n");
                                if (ctx->w == RES_IN || ctx->w == RES_FOR) {
                                        syntax();
                                        free(new);
                                        ctx->w = RES_SNTX;
                                        b_reset(dest);
                                        return 1;
                                }
                                *new = *ctx;   /* physical copy */
                                initialize_context(ctx);
                                ctx->stack=new;
                        } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
                                syntax();
                                ctx->w = RES_SNTX;
                                b_reset(dest);
                                return 1;
                        }
                        ctx->w=r->code;
                        ctx->old_flag = r->flag;
                        if (ctx->old_flag & FLAG_END) {
                                struct p_context *old;
                                debug("pop stack\n");
                                done_pipe(ctx,PIPE_SEQ);
                                old = ctx->stack;
                                old->child->group = ctx->list_head;
                                *ctx = *old;   /* physical copy */
                                free(old);
                        }
                        b_reset (dest);
                        return 1;
                }
        }
        return 0;
}

/* normal return is 0.
 * Syntax or xglob errors return 1. */
static int done_word(o_string *dest, struct p_context *ctx)
{
        struct child_prog *child=ctx->child;
        glob_t *glob_target;
        int gr, flags = 0;

        debug("done_word: %s %p\n", dest->data, child);
        if (dest->length == 0 && !dest->nonnull) {
                debug("  true null, ignored\n");
                return 0;
        }
        if (child->group) {
                syntax();
                return 1;  /* syntax error, groups and arglists don't mix */
        }
        if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
                debug("checking %s for reserved-ness\n",dest->data);
                if (reserved_word(dest,ctx))
                        return ctx->w==RES_SNTX;
        }

        glob_target = &child->glob_result;
        if (child->argv)
                flags |= GLOB_APPEND;

        gr = xglob(dest, flags, glob_target);
        if (gr)
                return 1;

        b_reset(dest);

        child->argv = glob_target->gl_pathv;
        child->argc = glob_target->gl_pathc;

        if (ctx->w == RES_FOR) {
                done_word(dest,ctx);
                done_pipe(ctx,PIPE_SEQ);
        }
        return 0;
}

/* The only possible error here is out of memory, in which case
 * xmalloc exits. */
static int done_command(struct p_context *ctx)
{
        /* The child is really already in the pipe structure, so
         * advance the pipe counter and make a new, null child.
         * Only real trickiness here is that the uncommitted
         * child structure, to which ctx->child points, is not
         * counted in pi->num_progs. */
        struct pipe *pi=ctx->pipe;
        struct child_prog *prog=ctx->child;

        if (prog && prog->group == NULL
                 && prog->argv == NULL
                                                                                ) {
                debug("done_command: skipping null command\n");
                return 0;
        } else if (prog) {
                pi->num_progs++;
                debug("done_command: num_progs incremented to %d\n",pi->num_progs);
        } else {
                debug("done_command: initializing\n");
        }
        pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));

        prog = pi->progs + pi->num_progs;
        prog->glob_result.gl_pathv = NULL;

        prog->argv = NULL;
        prog->group = NULL;
        prog->sp = 0;
        ctx->child = prog;
        prog->type = ctx->type;

        /* but ctx->pipe and ctx->list_head remain unchanged */
        return 0;
}

static int done_pipe(struct p_context *ctx, pipe_style type)
{
        struct pipe *new_p;
        done_command(ctx);  /* implicit closure of previous command */
        debug("done_pipe, type %d\n", type);
        ctx->pipe->followup = type;
        ctx->pipe->r_mode = ctx->w;
        new_p=new_pipe();
        ctx->pipe->next = new_p;
        ctx->pipe = new_p;
        ctx->child = NULL;
        done_command(ctx);  /* set up new pipe to accept commands */
        return 0;
}


/* basically useful version until someone wants to get fancier,
 * see the bash man page under "Parameter Expansion" */
static const char *lookup_param(char *src)
{
        if (!src)
                return NULL;

        if (*src == '$')
                return get_dollar_var(src[1]);

        return getenv(src);
}

static int parse_string(o_string *dest, struct p_context *ctx, const char *src)
{
        struct in_str foo;
        setup_string_in_str(&foo, src);
        return parse_stream(dest, ctx, &foo, '\0');
}

static char *get_dollar_var(char ch)
{
        static char buf[40];

        buf[0] = '\0';
        switch (ch) {
                case '?':
                        sprintf(buf, "%u", (unsigned int)last_return_code);
                        break;
                default:
                        return NULL;
        }
        return buf;
}

/* return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
{
        int advance = 0, i;
        int ch = input->peek(input);  /* first character after the $ */
        debug("handle_dollar: ch=%c\n",ch);
        if (isalpha(ch)) {
                b_addchr(dest, SPECIAL_VAR_SYMBOL);
                ctx->child->sp++;
                while(ch=b_peek(input),isalnum(ch) || ch=='_' || ch=='.') {
                        b_getch(input);
                        b_addchr(dest,ch);
                }
                b_addchr(dest, SPECIAL_VAR_SYMBOL);
        } else if (isdigit(ch)) {

                i = ch - '0';   /* XXX is $0 special? */
                if (i < ctx->global_argc) {
                        parse_string(dest, ctx, ctx->global_argv[i]);        /* recursion */
                }
                advance = 1;
        } else {
                switch (ch) {
                case '?':
                        ctx->child->sp++;
                        b_addchr(dest, SPECIAL_VAR_SYMBOL);
                        b_addchr(dest, '$');
                        b_addchr(dest, '?');
                        b_addchr(dest, SPECIAL_VAR_SYMBOL);
                        advance = 1;
                        break;
                case '#':
                        b_adduint(dest,ctx->global_argc ? ctx->global_argc-1 : 0);
                        advance = 1;
                        break;
                case '{':
                        b_addchr(dest, SPECIAL_VAR_SYMBOL);
                        ctx->child->sp++;
                        b_getch(input);
                        /* XXX maybe someone will try to escape the '}' */
                        while(ch=b_getch(input),ch!=EOF && ch!='}') {
                                b_addchr(dest,ch);
                        }
                        if (ch != '}') {
                                syntax();
                                return 1;
                        }
                        b_addchr(dest, SPECIAL_VAR_SYMBOL);
                        break;
                default:
                        b_addqchr(dest,'$',dest->quote);
                }
        }
        /* Eat the character if the flag was set.  If the compiler
         * is smart enough, we could substitute "b_getch(input);"
         * for all the "advance = 1;" above, and also end up with
         * a nice size-optimized program.  Hah!  That'll be the day.
         */
        if (advance)
                b_getch(input);
        return 0;
}


/* return code is 0 for normal exit, 1 for syntax error */
static int parse_stream(o_string *dest, struct p_context *ctx,
        struct in_str *input, int end_trigger)
{
        unsigned int ch, m;
        int next;

        /* Only double-quote state is handled in the state variable dest->quote.
         * A single-quote triggers a bypass of the main loop until its mate is
         * found.  When recursing, quote state is passed in via dest->quote. */

        debug("parse_stream, end_trigger=%d\n",end_trigger);
        while ((ch=b_getch(input))!=EOF) {
                m = map[ch];
                if (input->__promptme == 0)
                        return 1;
                next = (ch == '\n') ? 0 : b_peek(input);

                debug("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
                        ch >= ' ' ? ch : '.', ch, m,
                        dest->quote, ctx->stack == NULL ? '*' : '.');

                if (m==0 || ((m==1 || m==2) && dest->quote)) {
                        b_addqchr(dest, ch, dest->quote);
                } else {
                        if (m==2) {  /* unquoted IFS */
                                if (done_word(dest, ctx)) {
                                        return 1;
                                }
                                /* If we aren't performing a substitution, treat a newline as a
                                 * command separator.  */
                                if (end_trigger != '\0' && ch=='\n')
                                        done_pipe(ctx,PIPE_SEQ);
                        }
                        if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
                                debug("leaving parse_stream (triggered)\n");
                                return 0;
                        }
                        if (m!=2) {
                                switch (ch) {
                                case '#':
                                        if (dest->length == 0 && !dest->quote) {
                                                while(ch=b_peek(input),ch!=EOF && ch!='\n') {
                                                        b_getch(input);
                                                }
                                        } else {
                                                b_addqchr(dest, ch, dest->quote);
                                        }
                                        break;
                                case '\\':
                                        if (next == EOF) {
                                                syntax();
                                                return 1;
                                        }
                                        b_addqchr(dest, '\\', dest->quote);
                                        b_addqchr(dest, b_getch(input), dest->quote);
                                        break;
                                case '$':
                                        if (handle_dollar(dest, ctx, input)!=0)
                                                return 1;
                                        break;
                                case '\'':
                                        dest->nonnull = 1;
                                        while(ch=b_getch(input),ch!=EOF && ch!='\'') {
                                                if(input->__promptme == 0)
                                                        return 1;
                                                b_addchr(dest,ch);
                                        }
                                        if (ch==EOF) {
                                                syntax();
                                                return 1;
                                        }
                                        break;
                                case '"':
                                        dest->nonnull = 1;
                                        dest->quote = !dest->quote;
                                        break;
                                case ';':
                                        done_word(dest, ctx);
                                        done_pipe(ctx,PIPE_SEQ);
                                        break;
                                case '&':
                                        done_word(dest, ctx);
                                        if (next=='&') {
                                                b_getch(input);
                                                done_pipe(ctx,PIPE_AND);
                                        } else {
                                                syntax_err();
                                                return 1;
                                        }
                                        break;
                                case '|':
                                        done_word(dest, ctx);
                                        if (next=='|') {
                                                b_getch(input);
                                                done_pipe(ctx,PIPE_OR);
                                        } else {
                                                /* we could pick up a file descriptor choice here
                                                 * with redirect_opt_num(), but bash doesn't do it.
                                                 * "echo foo 2| cat" yields "foo 2". */
                                                syntax_err();
                                                return 1;
                                        }
                                        break;
                                default:
                                        syntax();   /* this is really an internal logic error */
                                        return 1;
                                }
                        }
                }
        }
        /* complain if quote?  No, maybe we just finished a command substitution
         * that was quoted.  Example:
         * $ echo "`cat foo` plus more"
         * and we just got the EOF generated by the subshell that ran "cat foo"
         * The only real complaint is if we got an EOF when end_trigger != '\0',
         * that is, we were really supposed to get end_trigger, and never got
         * one before the EOF.  Can't use the standard "syntax error" return code,
         * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
        debug("leaving parse_stream (EOF)\n");
        if (end_trigger != '\0') return -1;
        return 0;
}

static void mapset(const unsigned char *set, int code)
{
        const unsigned char *s;
        for (s=set; *s; s++) map[*s] = code;
}

static void update_ifs_map(void)
{
        /* char *ifs and char map[256] are both globals. */
        ifs = (uchar *)getenv("IFS");
        ifs = NULL;
        if (ifs == NULL) ifs=(uchar *)" \t\n";
        /* Precompute a list of 'flow through' behavior so it can be treated
         * quickly up front.  Computation is necessary because of IFS.
         * Special case handling of IFS == " \t\n" is not implemented.
         * The map[] array only really needs two bits each, and on most machines
         * that would be faster because of the reduced L1 cache footprint.
         */
        memset(map,0,sizeof(map)); /* most characters flow through always */
        mapset((uchar *)"\\$'\"", 3);       /* never flow through */
        mapset((uchar *)";&|#", 1);         /* flow through if quoted */
        mapset(ifs, 2);            /* also flow through if quoted */
}

/* most recursion does not come through here, the exeception is
 * from builtin_source() */
static int parse_stream_outer(struct p_context *ctx, struct in_str *inp, int flag)
{
        o_string temp=NULL_O_STRING;
        int rcode;
        int code = 0;
        do {
                ctx->type = flag;
                initialize_context(ctx);
                update_ifs_map();
                if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING))
                        mapset((uchar *)";$&|", 0);
                inp->promptmode=1;
                rcode = parse_stream(&temp, ctx, inp, '\n');
                if (rcode != 1 && ctx->old_flag != 0) {
                        syntax();
                }
                if (rcode != 1 && ctx->old_flag == 0) {
                        done_word(&temp, ctx);
                        done_pipe(ctx,PIPE_SEQ);
                        code = run_list(ctx->list_head);
                        if (code == -2) {       /* exit */
                                b_free(&temp);

                                /* XXX hackish way to not allow exit from main loop */
                                if (inp->peek == file_peek) {
                                        printf("exit not allowed from main input shell.\n");
                                        code = 0;
                                        continue;
                                }
                                break;
                        }
                } else {
                        if (ctx->old_flag != 0) {
                                free(ctx->stack);
                                b_reset(&temp);
                        }
                        if (inp->__promptme == 0)
                                printf("<INTERRUPT>\n");
                        inp->__promptme = 1;
                        temp.nonnull = 0;
                        temp.quote = 0;
                        inp->p = NULL;
                        free_pipe_list(ctx->list_head,0);
                }
                b_free(&temp);
        } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */

        return (code != 0) ? 1 : 0;
}

static int parse_string_outer(struct p_context *ctx, const char *s, int flag)
{
        struct in_str input;
        char *p;
        const char *cp;
        int rcode;

        if ( !s || !*s)
                return 1;

        cp = strchr(s, '\n');
        if (!cp || *++cp) {
                p = xmalloc(strlen(s) + 2);
                strcpy(p, s);
                strcat(p, "\n");
                setup_string_in_str(&input, p);
                rcode = parse_stream_outer(ctx, &input, flag);
                free(p);
                return rcode;
        } else {
                setup_string_in_str(&input, s);
                return parse_stream_outer(ctx, &input, flag);
        }
}

static char *insert_var_value(char *inp)
{
        int res_str_len = 0;
        int len;
        int done = 0;
        char *p, *res_str = NULL;
        const char *p1;

        while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
                if (p != inp) {
                        len = p - inp;
                        res_str = xrealloc(res_str, (res_str_len + len));
                        strncpy((res_str + res_str_len), inp, len);
                        res_str_len += len;
                }
                inp = ++p;
                p = strchr(inp, SPECIAL_VAR_SYMBOL);
                *p = '\0';
                if ((p1 = lookup_param(inp))) {
                        len = res_str_len + strlen(p1);
                        res_str = xrealloc(res_str, (1 + len));
                        strcpy((res_str + res_str_len), p1);
                        res_str_len = len;
                }
                *p = SPECIAL_VAR_SYMBOL;
                inp = ++p;
                done = 1;
        }
        if (done) {
                res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
                strcpy((res_str + res_str_len), inp);
                while ((p = strchr(res_str, '\n'))) {
                        *p = ' ';
                }
        }
        return (res_str == NULL) ? inp : res_str;
}

static char **make_list_in(char **inp, char *name)
{
        int len, i;
        int name_len = strlen(name);
        int n = 0;
        char **list;
        char *p1, *p2, *p3;

        /* create list of variable values */
        list = xmalloc(sizeof(*list));
        for (i = 0; inp[i]; i++) {
                p3 = insert_var_value(inp[i]);
                p1 = p3;
                while (*p1) {
                        if ((*p1 == ' ')) {
                                p1++;
                                continue;
                        }
                        if ((p2 = strchr(p1, ' '))) {
                                len = p2 - p1;
                        } else {
                                len = strlen(p1);
                                p2 = p1 + len;
                        }
                        /* we use n + 2 in realloc for list,because we add
                         * new element and then we will add NULL element */
                        list = xrealloc(list, sizeof(*list) * (n + 2));
                        list[n] = xmalloc(2 + name_len + len);
                        strcpy(list[n], name);
                        strcat(list[n], "=");
                        strncat(list[n], p1, len);
                        list[n++][name_len + len + 1] = '\0';
                        p1 = p2;
                }
                if (p3 != inp[i])
                        free(p3);
        }
        list[n] = NULL;
        return list;
}

/* Make new string for parser */
static char * make_string(char ** inp)
{
        char *p;
        char *str = NULL;
        int n;
        int len = 2;

        for (n = 0; inp[n]; n++) {
                p = insert_var_value(inp[n]);
                str = xrealloc(str, (len + strlen(p)));
                if (n) {
                        strcat(str, " ");
                } else {
                        *str = '\0';
                }
                strcat(str, p);
                len = strlen(str) + 3;
                if (p != inp[n])
                        free(p);
        }
        len = strlen(str);
        *(str + len) = '\n';
        *(str + len + 1) = '\0';
        return str;
}

int run_command (const char *cmd, int flag)
{
        struct p_context ctx;
        return parse_string_outer(&ctx, cmd, FLAG_PARSE_SEMICOLON);
}

static int execute_script(const char *path, int argc, char *argv[])
{
        int ret;

        env_push_context();
        ret = source_script(path, argc, argv);
        env_pop_context();

        return ret;
}

static int source_script(const char *path, int argc, char *argv[])
{
        struct p_context ctx;
        char *script;
        int ret;

        ctx.global_argc = argc;
        ctx.global_argv = argv;

        script = read_file(path, NULL);
        if (!script) {
                perror("sh");
                return 1;
        }

        ret = parse_string_outer(&ctx, script, FLAG_PARSE_SEMICOLON);

        free(script);

        return ret;
}

int run_shell(void)
{
        int rcode;
        struct in_str input;
        struct p_context ctx;

        setup_file_in_str(&input);
        rcode = parse_stream_outer(&ctx, &input, FLAG_PARSE_SEMICOLON);
        return rcode;
}

static int do_sh(cmd_tbl_t *cmdtp, int argc, char *argv[])
{
        if (argc < 2) {
                printf ("Usage:\n%s\n", cmdtp->usage);
                return 1;
        }

        return execute_script(argv[1], argc - 1, argv + 1);
}

static const __maybe_unused char cmd_sh_help[] =
"Usage: sh filename [arguments]\n"
"\n"
"Execute a shell script\n";

U_BOOT_CMD_START(sh)
        .maxargs        = CONFIG_MAXARGS,
        .cmd            = do_sh,
        .usage          = "run shell script",
        U_BOOT_CMD_HELP(cmd_sh_help)
U_BOOT_CMD_END

static int do_source(cmd_tbl_t *cmdtp, int argc, char *argv[])
{
        if (argc < 2) {
                printf ("Usage:\n%s\n", cmdtp->usage);
                return 1;
        }

        return source_script(argv[1], argc - 1, argv + 1);
}

static const char *source_aliases[] = { ".", NULL};

static const __maybe_unused char cmd_source_help[] =
"Usage: .  filename [arguments]\n"
"or     source filename [arguments]\n"
"\n"
"Read  and  execute  commands  from filename in the current shell\n"
"environment and return the exit status of the last command  exe-\n"
"cuted from filename\n";

static const __maybe_unused char cmd_source_usage[] =
"execute shell script in current shell environment";

U_BOOT_CMD_START(source)
        .maxargs        = CONFIG_MAXARGS,
        .aliases        = source_aliases,
        .cmd            = do_source,
        .usage          = cmd_source_usage,
        U_BOOT_CMD_HELP(cmd_source_help)
U_BOOT_CMD_END

/**
 * @file
 * @brief A prototype Bourne shell grammar parser
 */

/** @page sh_command Starting shell
 *
 * Usage: sh \<filename\> [\<arguments\>]
 *
 * Execute a shell script named \<filename\> and forward (if given)
 * \<arguments\> to it.
 *
 * Usage: .  \<filename\> [\<arguments\>]
 * or     source \<filename\> [\<arguments\>]
 *
 * Read and execute commands from \<filename\> in the current shell environment,
 * forward (if given) \<arguments\> to it and return the exit status of the last
 * command  executed from filename.
 */