contrib/libreadline/history.h

   1 /* History.h -- the names of functions that you can call in history. */
   2 /* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
   3
   4    This file contains the GNU History Library (the Library), a set of
   5    routines for managing the text of previously typed lines.
   6
   7    The Library is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    The Library is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16
  17    The GNU General Public License is often shipped with GNU software, and
  18    is generally kept in a file called COPYING or LICENSE.  If you do not
  19    have a copy of the license, write to the Free Software Foundation,
  20    59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  21
  22 #ifndef _HISTORY_H_
  23 #define _HISTORY_H_
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 #if defined READLINE_LIBRARY
  30 #  include "rlstdc.h"
  31 #else
  32 #  include <readline/rlstdc.h>
  33 #endif
  34
  35 #if !defined (_FUNCTION_DEF)
  36 #  define _FUNCTION_DEF
  37 typedef int Function ();
  38 typedef void VFunction ();
  39 typedef char *CPFunction ();
  40 typedef char **CPPFunction ();
  41 #endif
  42
  43 #ifdef __STDC__
  44 typedef void *histdata_t;
  45 #else
  46 typedef char *histdata_t;
  47 #endif
  48
  49 /* The structure used to store a history entry. */
  50 typedef struct _hist_entry {
  51   char *line;
  52   histdata_t data;
  53 } HIST_ENTRY;
  54
  55 /* A structure used to pass the current state of the history stuff around. */
  56 typedef struct _hist_state {
  57   HIST_ENTRY **entries;         /* Pointer to the entries themselves. */
  58   int offset;                   /* The location pointer within this array. */
  59   int length;                   /* Number of elements within this array. */
  60   int size;                     /* Number of slots allocated to this array. */
  61   int flags;
  62 } HISTORY_STATE;
  63
  64 /* Flag values for the `flags' member of HISTORY_STATE. */
  65 #define HS_STIFLED      0x01
  66
  67 /* Initialization and state management. */
  68
  69 /* Begin a session in which the history functions might be used.  This
  70    just initializes the interactive variables. */
  71 extern void using_history __P((void));
  72
  73 /* Return the current HISTORY_STATE of the history. */
  74 extern HISTORY_STATE *history_get_history_state __P((void));
  75
  76 /* Set the state of the current history array to STATE. */
  77 extern void history_set_history_state __P((HISTORY_STATE *));
  78
  79 /* Manage the history list. */
  80
  81 /* Place STRING at the end of the history list.
  82    The associated data field (if any) is set to NULL. */
  83 extern void add_history __P((char *));
  84
  85 /* A reasonably useless function, only here for completeness.  WHICH
  86    is the magic number that tells us which element to delete.  The
  87    elements are numbered from 0. */
  88 extern HIST_ENTRY *remove_history __P((int));
  89
  90 /* Make the history entry at WHICH have LINE and DATA.  This returns
  91    the old entry so you can dispose of the data.  In the case of an
  92    invalid WHICH, a NULL pointer is returned. */
  93 extern HIST_ENTRY *replace_history_entry __P((int, char *, histdata_t));
  94
  95 /* Clear the history list and start over. */
  96 extern void clear_history __P((void));
  97
  98 /* Stifle the history list, remembering only MAX number of entries. */
  99 extern void stifle_history __P((int));
 100
 101 /* Stop stifling the history.  This returns the previous amount the
 102    history was stifled by.  The value is positive if the history was
 103    stifled, negative if it wasn't. */
 104 extern int unstifle_history __P((void));
 105
 106 /* Return 1 if the history is stifled, 0 if it is not. */
 107 extern int history_is_stifled __P((void));
 108
 109 /* Information about the history list. */
 110
 111 /* Return a NULL terminated array of HIST_ENTRY which is the current input
 112    history.  Element 0 of this list is the beginning of time.  If there
 113    is no history, return NULL. */
 114 extern HIST_ENTRY **history_list __P((void));
 115
 116 /* Returns the number which says what history element we are now
 117    looking at.  */
 118 extern int where_history __P((void));
 119
 120 /* Return the history entry at the current position, as determined by
 121    history_offset.  If there is no entry there, return a NULL pointer. */
 122 extern HIST_ENTRY *current_history __P((void));
 123
 124 /* Return the history entry which is logically at OFFSET in the history
 125    array.  OFFSET is relative to history_base. */
 126 extern HIST_ENTRY *history_get __P((int));
 127
 128 /* Return the number of bytes that the primary history entries are using.
 129    This just adds up the lengths of the_history->lines. */
 130 extern int history_total_bytes __P((void));
 131
 132 /* Moving around the history list. */
 133
 134 /* Set the position in the history list to POS. */
 135 extern int history_set_pos __P((int));
 136
 137 /* Back up history_offset to the previous history entry, and return
 138    a pointer to that entry.  If there is no previous entry, return
 139    a NULL pointer. */
 140 extern HIST_ENTRY *previous_history __P((void));
 141
 142 /* Move history_offset forward to the next item in the input_history,
 143    and return the a pointer to that entry.  If there is no next entry,
 144    return a NULL pointer. */
 145 extern HIST_ENTRY *next_history __P((void));
 146
 147 /* Searching the history list. */
 148
 149 /* Search the history for STRING, starting at history_offset.
 150    If DIRECTION < 0, then the search is through previous entries,
 151    else through subsequent.  If the string is found, then
 152    current_history () is the history entry, and the value of this function
 153    is the offset in the line of that history entry that the string was
 154    found in.  Otherwise, nothing is changed, and a -1 is returned. */
 155 extern int history_search __P((char *, int));
 156
 157 /* Search the history for STRING, starting at history_offset.
 158    The search is anchored: matching lines must begin with string.
 159    DIRECTION is as in history_search(). */
 160 extern int history_search_prefix __P((char *, int));
 161
 162 /* Search for STRING in the history list, starting at POS, an
 163    absolute index into the list.  DIR, if negative, says to search
 164    backwards from POS, else forwards.
 165    Returns the absolute index of the history element where STRING
 166    was found, or -1 otherwise. */
 167 extern int history_search_pos __P((char *, int, int));
 168
 169 /* Managing the history file. */
 170
 171 /* Add the contents of FILENAME to the history list, a line at a time.
 172    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
 173    successful, or errno if not. */
 174 extern int read_history __P((char *));
 175
 176 /* Read a range of lines from FILENAME, adding them to the history list.
 177    Start reading at the FROM'th line and end at the TO'th.  If FROM
 178    is zero, start at the beginning.  If TO is less than FROM, read
 179    until the end of the file.  If FILENAME is NULL, then read from
 180    ~/.history.  Returns 0 if successful, or errno if not. */
 181 extern int read_history_range __P((char *, int, int));
 182
 183 /* Write the current history to FILENAME.  If FILENAME is NULL,
 184    then write the history list to ~/.history.  Values returned
 185    are as in read_history ().  */
 186 extern int write_history __P((char *));
 187
 188 /* Append NELEMENT entries to FILENAME.  The entries appended are from
 189    the end of the list minus NELEMENTs up to the end of the list. */
 190 extern int append_history __P((int, char *));
 191
 192 /* Truncate the history file, leaving only the last NLINES lines. */
 193 extern int history_truncate_file __P((char *, int));
 194
 195 /* History expansion. */
 196
 197 /* Expand the string STRING, placing the result into OUTPUT, a pointer
 198    to a string.  Returns:
 199
 200    0) If no expansions took place (or, if the only change in
 201       the text was the de-slashifying of the history expansion
 202       character)
 203    1) If expansions did take place
 204   -1) If there was an error in expansion.
 205    2) If the returned line should just be printed.
 206
 207   If an error ocurred in expansion, then OUTPUT contains a descriptive
 208   error message. */
 209 extern int history_expand __P((char *, char **));
 210
 211 /* Extract a string segment consisting of the FIRST through LAST
 212    arguments present in STRING.  Arguments are broken up as in
 213    the shell. */
 214 extern char *history_arg_extract __P((int, int, char *));
 215
 216 /* Return the text of the history event beginning at the current
 217    offset into STRING.  Pass STRING with *INDEX equal to the
 218    history_expansion_char that begins this specification.
 219    DELIMITING_QUOTE is a character that is allowed to end the string
 220    specification for what to search for in addition to the normal
 221    characters `:', ` ', `\t', `\n', and sometimes `?'. */
 222 extern char *get_history_event __P((char *, int *, int));
 223
 224 /* Return an array of tokens, much as the shell might.  The tokens are
 225    parsed out of STRING. */
 226 extern char **history_tokenize __P((char *));
 227
 228 /* Exported history variables. */
 229 extern int history_base;
 230 extern int history_length;
 231 extern int max_input_history;
 232 extern char history_expansion_char;
 233 extern char history_subst_char;
 234 extern char history_comment_char;
 235 extern char *history_no_expand_chars;
 236 extern char *history_search_delimiter_chars;
 237 extern int history_quotes_inhibit_expansion;
 238
 239 /* If set, this function is called to decide whether or not a particular
 240    history expansion should be treated as a special case for the calling
 241    application and not expanded. */
 242 extern Function *history_inhibit_expansion_function;
 243
 244 #ifdef __cplusplus
 245 }
 246 #endif
 247
 248 #endif /* !_HISTORY_H_ */