readline/history.h

   1 /* history.h -- the names of functions that you can call in history. */
   2
   3 /* Copyright (C) 1989-2009 Free Software Foundation, Inc.
   4
   5    This file contains the GNU History Library (History), a set of
   6    routines for managing the text of previously typed lines.
   7
   8    History is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    History is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with History.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #ifndef _HISTORY_H_
  23 #define _HISTORY_H_
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 #include <time.h>               /* XXX - for history timestamp code */
  30
  31 #if defined READLINE_LIBRARY
  32 #  include "rlstdc.h"
  33 #  include "rltypedefs.h"
  34 #else
  35 #  include <readline/rlstdc.h>
  36 #  include <readline/rltypedefs.h>
  37 #endif
  38
  39 #ifdef __STDC__
  40 typedef void *histdata_t;
  41 #else
  42 typedef char *histdata_t;
  43 #endif
  44
  45 /* The structure used to store a history entry. */
  46 typedef struct _hist_entry {
  47   char *line;
  48   char *timestamp;              /* char * rather than time_t for read/write */
  49   histdata_t data;
  50 } HIST_ENTRY;
  51
  52 /* Size of the history-library-managed space in history entry HS. */
  53 #define HISTENT_BYTES(hs)       (strlen ((hs)->line) + strlen ((hs)->timestamp))
  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 PARAMS((void));
  72
  73 /* Return the current HISTORY_STATE of the history. */
  74 extern HISTORY_STATE *history_get_history_state PARAMS((void));
  75
  76 /* Set the state of the current history array to STATE. */
  77 extern void history_set_history_state PARAMS((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 PARAMS((const char *));
  84
  85 /* Change the timestamp associated with the most recent history entry to
  86    STRING. */
  87 extern void add_history_time PARAMS((const char *));
  88
  89 /* A reasonably useless function, only here for completeness.  WHICH
  90    is the magic number that tells us which element to delete.  The
  91    elements are numbered from 0. */
  92 extern HIST_ENTRY *remove_history PARAMS((int));
  93
  94 /* Free the history entry H and return any application-specific data
  95    associated with it. */
  96 extern histdata_t free_history_entry PARAMS((HIST_ENTRY *));
  97
  98 /* Make the history entry at WHICH have LINE and DATA.  This returns
  99    the old entry so you can dispose of the data.  In the case of an
 100    invalid WHICH, a NULL pointer is returned. */
 101 extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
 102
 103 /* Clear the history list and start over. */
 104 extern void clear_history PARAMS((void));
 105
 106 /* Stifle the history list, remembering only MAX number of entries. */
 107 extern void stifle_history PARAMS((int));
 108
 109 /* Stop stifling the history.  This returns the previous amount the
 110    history was stifled by.  The value is positive if the history was
 111    stifled, negative if it wasn't. */
 112 extern int unstifle_history PARAMS((void));
 113
 114 /* Return 1 if the history is stifled, 0 if it is not. */
 115 extern int history_is_stifled PARAMS((void));
 116
 117 /* Information about the history list. */
 118
 119 /* Return a NULL terminated array of HIST_ENTRY which is the current input
 120    history.  Element 0 of this list is the beginning of time.  If there
 121    is no history, return NULL. */
 122 extern HIST_ENTRY **history_list PARAMS((void));
 123
 124 /* Returns the number which says what history element we are now
 125    looking at.  */
 126 extern int where_history PARAMS((void));
 127
 128 /* Return the history entry at the current position, as determined by
 129    history_offset.  If there is no entry there, return a NULL pointer. */
 130 extern HIST_ENTRY *current_history PARAMS((void));
 131
 132 /* Return the history entry which is logically at OFFSET in the history
 133    array.  OFFSET is relative to history_base. */
 134 extern HIST_ENTRY *history_get PARAMS((int));
 135
 136 /* Return the timestamp associated with the HIST_ENTRY * passed as an
 137    argument */
 138 extern time_t history_get_time PARAMS((HIST_ENTRY *));
 139
 140 /* Return the number of bytes that the primary history entries are using.
 141    This just adds up the lengths of the_history->lines. */
 142 extern int history_total_bytes PARAMS((void));
 143
 144 /* Moving around the history list. */
 145
 146 /* Set the position in the history list to POS. */
 147 extern int history_set_pos PARAMS((int));
 148
 149 /* Back up history_offset to the previous history entry, and return
 150    a pointer to that entry.  If there is no previous entry, return
 151    a NULL pointer. */
 152 extern HIST_ENTRY *previous_history PARAMS((void));
 153
 154 /* Move history_offset forward to the next item in the input_history,
 155    and return the a pointer to that entry.  If there is no next entry,
 156    return a NULL pointer. */
 157 extern HIST_ENTRY *next_history PARAMS((void));
 158
 159 /* Searching the history list. */
 160
 161 /* Search the history for STRING, starting at history_offset.
 162    If DIRECTION < 0, then the search is through previous entries,
 163    else through subsequent.  If the string is found, then
 164    current_history () is the history entry, and the value of this function
 165    is the offset in the line of that history entry that the string was
 166    found in.  Otherwise, nothing is changed, and a -1 is returned. */
 167 extern int history_search PARAMS((const char *, int));
 168
 169 /* Search the history for STRING, starting at history_offset.
 170    The search is anchored: matching lines must begin with string.
 171    DIRECTION is as in history_search(). */
 172 extern int history_search_prefix PARAMS((const char *, int));
 173
 174 /* Search for STRING in the history list, starting at POS, an
 175    absolute index into the list.  DIR, if negative, says to search
 176    backwards from POS, else forwards.
 177    Returns the absolute index of the history element where STRING
 178    was found, or -1 otherwise. */
 179 extern int history_search_pos PARAMS((const char *, int, int));
 180
 181 /* Managing the history file. */
 182
 183 /* Add the contents of FILENAME to the history list, a line at a time.
 184    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
 185    successful, or errno if not. */
 186 extern int read_history PARAMS((const char *));
 187
 188 /* Read a range of lines from FILENAME, adding them to the history list.
 189    Start reading at the FROM'th line and end at the TO'th.  If FROM
 190    is zero, start at the beginning.  If TO is less than FROM, read
 191    until the end of the file.  If FILENAME is NULL, then read from
 192    ~/.history.  Returns 0 if successful, or errno if not. */
 193 extern int read_history_range PARAMS((const char *, int, int));
 194
 195 /* Write the current history to FILENAME.  If FILENAME is NULL,
 196    then write the history list to ~/.history.  Values returned
 197    are as in read_history ().  */
 198 extern int write_history PARAMS((const char *));
 199
 200 /* Append NELEMENT entries to FILENAME.  The entries appended are from
 201    the end of the list minus NELEMENTs up to the end of the list. */
 202 extern int append_history PARAMS((int, const char *));
 203
 204 /* Truncate the history file, leaving only the last NLINES lines. */
 205 extern int history_truncate_file PARAMS((const char *, int));
 206
 207 /* History expansion. */
 208
 209 /* Expand the string STRING, placing the result into OUTPUT, a pointer
 210    to a string.  Returns:
 211
 212    0) If no expansions took place (or, if the only change in
 213       the text was the de-slashifying of the history expansion
 214       character)
 215    1) If expansions did take place
 216   -1) If there was an error in expansion.
 217    2) If the returned line should just be printed.
 218
 219   If an error ocurred in expansion, then OUTPUT contains a descriptive
 220   error message. */
 221 extern int history_expand PARAMS((char *, char **));
 222
 223 /* Extract a string segment consisting of the FIRST through LAST
 224    arguments present in STRING.  Arguments are broken up as in
 225    the shell. */
 226 extern char *history_arg_extract PARAMS((int, int, const char *));
 227
 228 /* Return the text of the history event beginning at the current
 229    offset into STRING.  Pass STRING with *INDEX equal to the
 230    history_expansion_char that begins this specification.
 231    DELIMITING_QUOTE is a character that is allowed to end the string
 232    specification for what to search for in addition to the normal
 233    characters `:', ` ', `\t', `\n', and sometimes `?'. */
 234 extern char *get_history_event PARAMS((const char *, int *, int));
 235
 236 /* Return an array of tokens, much as the shell might.  The tokens are
 237    parsed out of STRING. */
 238 extern char **history_tokenize PARAMS((const char *));
 239
 240 /* Exported history variables. */
 241 extern int history_base;
 242 extern int history_length;
 243 extern int history_max_entries;
 244 extern char history_expansion_char;
 245 extern char history_subst_char;
 246 extern char *history_word_delimiters;
 247 extern char history_comment_char;
 248 extern char *history_no_expand_chars;
 249 extern char *history_search_delimiter_chars;
 250 extern int history_quotes_inhibit_expansion;
 251
 252 extern int history_write_timestamps;
 253
 254 /* Backwards compatibility */
 255 extern int max_input_history;
 256
 257 /* If set, this function is called to decide whether or not a particular
 258    history expansion should be treated as a special case for the calling
 259    application and not expanded. */
 260 extern rl_linebuf_func_t *history_inhibit_expansion_function;
 261
 262 #ifdef __cplusplus
 263 }
 264 #endif
 265
 266 #endif /* !_HISTORY_H_ */