readline/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 #  include "rltypedefs.h"
  32 #else
  33 #  include <readline/rlstdc.h>
  34 #  include <readline/rltypedefs.h>
  35 #endif
  36
  37 #ifdef __STDC__
  38 typedef void *histdata_t;
  39 #else
  40 typedef char *histdata_t;
  41 #endif
  42
  43 /* The structure used to store a history entry. */
  44 typedef struct _hist_entry {
  45   char *line;
  46   histdata_t data;
  47 } HIST_ENTRY;
  48
  49 /* A structure used to pass the current state of the history stuff around. */
  50 typedef struct _hist_state {
  51   HIST_ENTRY **entries;         /* Pointer to the entries themselves. */
  52   int offset;                   /* The location pointer within this array. */
  53   int length;                   /* Number of elements within this array. */
  54   int size;                     /* Number of slots allocated to this array. */
  55   int flags;
  56 } HISTORY_STATE;
  57
  58 /* Flag values for the `flags' member of HISTORY_STATE. */
  59 #define HS_STIFLED      0x01
  60
  61 /* Initialization and state management. */
  62
  63 /* Begin a session in which the history functions might be used.  This
  64    just initializes the interactive variables. */
  65 extern void using_history PARAMS((void));
  66
  67 /* Return the current HISTORY_STATE of the history. */
  68 extern HISTORY_STATE *history_get_history_state PARAMS((void));
  69
  70 /* Set the state of the current history array to STATE. */
  71 extern void history_set_history_state PARAMS((HISTORY_STATE *));
  72
  73 /* Manage the history list. */
  74
  75 /* Place STRING at the end of the history list.
  76    The associated data field (if any) is set to NULL. */
  77 extern void add_history PARAMS((const char *));
  78
  79 /* A reasonably useless function, only here for completeness.  WHICH
  80    is the magic number that tells us which element to delete.  The
  81    elements are numbered from 0. */
  82 extern HIST_ENTRY *remove_history PARAMS((int));
  83
  84 /* Make the history entry at WHICH have LINE and DATA.  This returns
  85    the old entry so you can dispose of the data.  In the case of an
  86    invalid WHICH, a NULL pointer is returned. */
  87 extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
  88
  89 /* Clear the history list and start over. */
  90 extern void clear_history PARAMS((void));
  91
  92 /* Stifle the history list, remembering only MAX number of entries. */
  93 extern void stifle_history PARAMS((int));
  94
  95 /* Stop stifling the history.  This returns the previous amount the
  96    history was stifled by.  The value is positive if the history was
  97    stifled, negative if it wasn't. */
  98 extern int unstifle_history PARAMS((void));
  99
 100 /* Return 1 if the history is stifled, 0 if it is not. */
 101 extern int history_is_stifled PARAMS((void));
 102
 103 /* Information about the history list. */
 104
 105 /* Return a NULL terminated array of HIST_ENTRY which is the current input
 106    history.  Element 0 of this list is the beginning of time.  If there
 107    is no history, return NULL. */
 108 extern HIST_ENTRY **history_list PARAMS((void));
 109
 110 /* Returns the number which says what history element we are now
 111    looking at.  */
 112 extern int where_history PARAMS((void));
 113
 114 /* Return the history entry at the current position, as determined by
 115    history_offset.  If there is no entry there, return a NULL pointer. */
 116 extern HIST_ENTRY *current_history PARAMS((void));
 117
 118 /* Return the history entry which is logically at OFFSET in the history
 119    array.  OFFSET is relative to history_base. */
 120 extern HIST_ENTRY *history_get PARAMS((int));
 121
 122 /* Return the number of bytes that the primary history entries are using.
 123    This just adds up the lengths of the_history->lines. */
 124 extern int history_total_bytes PARAMS((void));
 125
 126 /* Moving around the history list. */
 127
 128 /* Set the position in the history list to POS. */
 129 extern int history_set_pos PARAMS((int));
 130
 131 /* Back up history_offset to the previous history entry, and return
 132    a pointer to that entry.  If there is no previous entry, return
 133    a NULL pointer. */
 134 extern HIST_ENTRY *previous_history PARAMS((void));
 135
 136 /* Move history_offset forward to the next item in the input_history,
 137    and return the a pointer to that entry.  If there is no next entry,
 138    return a NULL pointer. */
 139 extern HIST_ENTRY *next_history PARAMS((void));
 140
 141 /* Searching the history list. */
 142
 143 /* Search the history for STRING, starting at history_offset.
 144    If DIRECTION < 0, then the search is through previous entries,
 145    else through subsequent.  If the string is found, then
 146    current_history () is the history entry, and the value of this function
 147    is the offset in the line of that history entry that the string was
 148    found in.  Otherwise, nothing is changed, and a -1 is returned. */
 149 extern int history_search PARAMS((const char *, int));
 150
 151 /* Search the history for STRING, starting at history_offset.
 152    The search is anchored: matching lines must begin with string.
 153    DIRECTION is as in history_search(). */
 154 extern int history_search_prefix PARAMS((const char *, int));
 155
 156 /* Search for STRING in the history list, starting at POS, an
 157    absolute index into the list.  DIR, if negative, says to search
 158    backwards from POS, else forwards.
 159    Returns the absolute index of the history element where STRING
 160    was found, or -1 otherwise. */
 161 extern int history_search_pos PARAMS((const char *, int, int));
 162
 163 /* Managing the history file. */
 164
 165 /* Add the contents of FILENAME to the history list, a line at a time.
 166    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
 167    successful, or errno if not. */
 168 extern int read_history PARAMS((const char *));
 169
 170 /* Read a range of lines from FILENAME, adding them to the history list.
 171    Start reading at the FROM'th line and end at the TO'th.  If FROM
 172    is zero, start at the beginning.  If TO is less than FROM, read
 173    until the end of the file.  If FILENAME is NULL, then read from
 174    ~/.history.  Returns 0 if successful, or errno if not. */
 175 extern int read_history_range PARAMS((const char *, int, int));
 176
 177 /* Write the current history to FILENAME.  If FILENAME is NULL,
 178    then write the history list to ~/.history.  Values returned
 179    are as in read_history ().  */
 180 extern int write_history PARAMS((const char *));
 181
 182 /* Append NELEMENT entries to FILENAME.  The entries appended are from
 183    the end of the list minus NELEMENTs up to the end of the list. */
 184 extern int append_history PARAMS((int, const char *));
 185
 186 /* Truncate the history file, leaving only the last NLINES lines. */
 187 extern int history_truncate_file PARAMS((const char *, int));
 188
 189 /* History expansion. */
 190
 191 /* Expand the string STRING, placing the result into OUTPUT, a pointer
 192    to a string.  Returns:
 193
 194    0) If no expansions took place (or, if the only change in
 195       the text was the de-slashifying of the history expansion
 196       character)
 197    1) If expansions did take place
 198   -1) If there was an error in expansion.
 199    2) If the returned line should just be printed.
 200
 201   If an error ocurred in expansion, then OUTPUT contains a descriptive
 202   error message. */
 203 extern int history_expand PARAMS((char *, char **));
 204
 205 /* Extract a string segment consisting of the FIRST through LAST
 206    arguments present in STRING.  Arguments are broken up as in
 207    the shell. */
 208 extern char *history_arg_extract PARAMS((int, int, const char *));
 209
 210 /* Return the text of the history event beginning at the current
 211    offset into STRING.  Pass STRING with *INDEX equal to the
 212    history_expansion_char that begins this specification.
 213    DELIMITING_QUOTE is a character that is allowed to end the string
 214    specification for what to search for in addition to the normal
 215    characters `:', ` ', `\t', `\n', and sometimes `?'. */
 216 extern char *get_history_event PARAMS((const char *, int *, int));
 217
 218 /* Return an array of tokens, much as the shell might.  The tokens are
 219    parsed out of STRING. */
 220 extern char **history_tokenize PARAMS((const char *));
 221
 222 /* Exported history variables. */
 223 extern int history_base;
 224 extern int history_length;
 225 extern int history_max_entries;
 226 extern char history_expansion_char;
 227 extern char history_subst_char;
 228 extern char *history_word_delimiters;
 229 extern char history_comment_char;
 230 extern char *history_no_expand_chars;
 231 extern char *history_search_delimiter_chars;
 232 extern int history_quotes_inhibit_expansion;
 233
 234 /* Backwards compatibility */
 235 extern int max_input_history;
 236
 237 /* If set, this function is called to decide whether or not a particular
 238    history expansion should be treated as a special case for the calling
 239    application and not expanded. */
 240 extern rl_linebuf_func_t *history_inhibit_expansion_function;
 241
 242 #ifdef __cplusplus
 243 }
 244 #endif
 245
 246 #endif /* !_HISTORY_H_ */