lib/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 1, 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    675 Mass Ave, Cambridge, MA 02139, USA. */
  21
  22 #ifndef _HISTORY_H_
  23 #define _HISTORY_H_
  24
  25 #if !defined (_FUNCTION_DEF)
  26 #  define _FUNCTION_DEF
  27 typedef int Function ();
  28 typedef void VFunction ();
  29 typedef char *CPFunction ();
  30 typedef char **CPPFunction ();
  31 #endif
  32
  33 /* The structure used to store a history entry. */
  34 typedef struct _hist_entry {
  35   char *line;
  36   char *data;
  37 } HIST_ENTRY;
  38
  39 /* A structure used to pass the current state of the history stuff around. */
  40 typedef struct _hist_state {
  41   HIST_ENTRY **entries;         /* Pointer to the entries themselves. */
  42   int offset;                   /* The location pointer within this array. */
  43   int length;                   /* Number of elements within this array. */
  44   int size;                     /* Number of slots allocated to this array. */
  45   int flags;
  46 } HISTORY_STATE;
  47
  48 /* Flag values for the `flags' member of HISTORY_STATE. */
  49 #define HS_STIFLED      0x01
  50
  51 /* Initialization and state management. */
  52
  53 /* Begin a session in which the history functions might be used.  This
  54    just initializes the interactive variables. */
  55 extern void using_history ();
  56
  57 /* Return the current HISTORY_STATE of the history. */
  58 extern HISTORY_STATE *history_get_history_state ();
  59
  60 /* Set the state of the current history array to STATE. */
  61 extern void history_set_history_state ();
  62
  63 /* Manage the history list. */
  64
  65 /* Place STRING at the end of the history list.
  66    The associated data field (if any) is set to NULL. */
  67 extern void add_history ();
  68
  69 /* A reasonably useless function, only here for completeness.  WHICH
  70    is the magic number that tells us which element to delete.  The
  71    elements are numbered from 0. */
  72 extern HIST_ENTRY *remove_history ();
  73
  74 /* Make the history entry at WHICH have LINE and DATA.  This returns
  75    the old entry so you can dispose of the data.  In the case of an
  76    invalid WHICH, a NULL pointer is returned. */
  77 extern HIST_ENTRY *replace_history_entry ();
  78
  79 /* Clear the history list and start over. */
  80 extern void clear_history ();
  81
  82 /* Stifle the history list, remembering only MAX number of entries. */
  83 extern void stifle_history ();
  84
  85 /* Stop stifling the history.  This returns the previous amount the
  86    history was stifled by.  The value is positive if the history was
  87    stifled, negative if it wasn't. */
  88 extern int unstifle_history ();
  89
  90 /* Return 1 if the history is stifled, 0 if it is not. */
  91 extern int history_is_stifled ();
  92
  93 /* Information about the history list. */
  94
  95 /* Return a NULL terminated array of HIST_ENTRY which is the current input
  96    history.  Element 0 of this list is the beginning of time.  If there
  97    is no history, return NULL. */
  98 extern HIST_ENTRY **history_list ();
  99
 100 /* Returns the number which says what history element we are now
 101    looking at.  */
 102 extern int where_history ();
 103
 104 /* Return the history entry at the current position, as determined by
 105    history_offset.  If there is no entry there, return a NULL pointer. */
 106 HIST_ENTRY *current_history ();
 107
 108 /* Return the history entry which is logically at OFFSET in the history
 109    array.  OFFSET is relative to history_base. */
 110 extern HIST_ENTRY *history_get ();
 111
 112 /* Return the number of bytes that the primary history entries are using.
 113    This just adds up the lengths of the_history->lines. */
 114 extern int history_total_bytes ();
 115
 116 /* Moving around the history list. */
 117
 118 /* Set the position in the history list to POS. */
 119 int history_set_pos ();
 120
 121 /* Back up history_offset to the previous history entry, and return
 122    a pointer to that entry.  If there is no previous entry, return
 123    a NULL pointer. */
 124 extern HIST_ENTRY *previous_history ();
 125
 126 /* Move history_offset forward to the next item in the input_history,
 127    and return the a pointer to that entry.  If there is no next entry,
 128    return a NULL pointer. */
 129 extern HIST_ENTRY *next_history ();
 130
 131 /* Searching the history list. */
 132
 133 /* Search the history for STRING, starting at history_offset.
 134    If DIRECTION < 0, then the search is through previous entries,
 135    else through subsequent.  If the string is found, then
 136    current_history () is the history entry, and the value of this function
 137    is the offset in the line of that history entry that the string was
 138    found in.  Otherwise, nothing is changed, and a -1 is returned. */
 139 extern int history_search ();
 140
 141 /* Search the history for STRING, starting at history_offset.
 142    The search is anchored: matching lines must begin with string. */
 143 extern int history_search_prefix ();
 144
 145 /* Search for STRING in the history list, starting at POS, an
 146    absolute index into the list.  DIR, if negative, says to search
 147    backwards from POS, else forwards.
 148    Returns the absolute index of the history element where STRING
 149    was found, or -1 otherwise. */
 150 extern int history_search_pos ();
 151
 152 /* Managing the history file. */
 153
 154 /* Add the contents of FILENAME to the history list, a line at a time.
 155    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
 156    successful, or errno if not. */
 157 extern int read_history ();
 158
 159 /* Read a range of lines from FILENAME, adding them to the history list.
 160    Start reading at the FROM'th line and end at the TO'th.  If FROM
 161    is zero, start at the beginning.  If TO is less than FROM, read
 162    until the end of the file.  If FILENAME is NULL, then read from
 163    ~/.history.  Returns 0 if successful, or errno if not. */
 164 extern int read_history_range ();
 165
 166 /* Write the current history to FILENAME.  If FILENAME is NULL,
 167    then write the history list to ~/.history.  Values returned
 168    are as in read_history ().  */
 169 extern int write_history ();
 170
 171 /* Append NELEMENT entries to FILENAME.  The entries appended are from
 172    the end of the list minus NELEMENTs up to the end of the list. */
 173 int append_history ();
 174
 175 /* Truncate the history file, leaving only the last NLINES lines. */
 176 extern int history_truncate_file ();
 177
 178 /* History expansion. */
 179
 180 /* Expand the string STRING, placing the result into OUTPUT, a pointer
 181    to a string.  Returns:
 182
 183    0) If no expansions took place (or, if the only change in
 184       the text was the de-slashifying of the history expansion
 185       character)
 186    1) If expansions did take place
 187   -1) If there was an error in expansion.
 188    2) If the returned line should just be printed.
 189
 190   If an error ocurred in expansion, then OUTPUT contains a descriptive
 191   error message. */
 192 extern int history_expand ();
 193
 194 /* Extract a string segment consisting of the FIRST through LAST
 195    arguments present in STRING.  Arguments are broken up as in
 196    the shell. */
 197 extern char *history_arg_extract ();
 198
 199 /* Return the text of the history event beginning at the current
 200    offset into STRING. */
 201 extern char *get_history_event ();
 202
 203 /* Return an array of tokens, much as the shell might.  The tokens are
 204    parsed out of STRING. */
 205 extern char **history_tokenize ();
 206
 207 /* Exported history variables. */
 208 extern int history_base;
 209 extern int history_length;
 210 extern int max_input_history;
 211 extern char history_expansion_char;
 212 extern char history_subst_char;
 213 extern char history_comment_char;
 214 extern char *history_no_expand_chars;
 215 extern char *history_search_delimiter_chars;
 216 extern int history_quotes_inhibit_expansion;
 217
 218 /* If set, this function is called to decide whether or not a particular
 219    history expansion should be treated as a special case for the calling
 220    application and not expanded. */
 221 extern Function *history_inhibit_expansion_function;
 222
 223 #endif /* !_HISTORY_H_ */