readline/history.h

   1 /* history.h -- the names of functions that you can call in history. */
   2
   3 /* Copyright (C) 1989-2015 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 /* Remove an entry from the history list.  WHICH is the magic number that
  90    tells us which element to delete.  The elements are numbered from 0. */
  91 extern HIST_ENTRY *remove_history PARAMS((int));
  92
  93 /* Remove a set of entries from the history list: FIRST to LAST, inclusive */
  94 extern HIST_ENTRY **remove_history_range PARAMS((int, int));
  95
  96 /* Allocate a history entry consisting of STRING and TIMESTAMP and return
  97    a pointer to it. */
  98 extern HIST_ENTRY *alloc_history_entry PARAMS((char *, char *));
  99
 100 /* Copy the history entry H, but not the (opaque) data pointer */
 101 extern HIST_ENTRY *copy_history_entry PARAMS((HIST_ENTRY *));
 102
 103 /* Free the history entry H and return any application-specific data
 104    associated with it. */
 105 extern histdata_t free_history_entry PARAMS((HIST_ENTRY *));
 106
 107 /* Make the history entry at WHICH have LINE and DATA.  This returns
 108    the old entry so you can dispose of the data.  In the case of an
 109    invalid WHICH, a NULL pointer is returned. */
 110 extern HIST_ENTRY *replace_history_entry PARAMS((int, const char *, histdata_t));
 111
 112 /* Clear the history list and start over. */
 113 extern void clear_history PARAMS((void));
 114
 115 /* Stifle the history list, remembering only MAX number of entries. */
 116 extern void stifle_history PARAMS((int));
 117
 118 /* Stop stifling the history.  This returns the previous amount the
 119    history was stifled by.  The value is positive if the history was
 120    stifled, negative if it wasn't. */
 121 extern int unstifle_history PARAMS((void));
 122
 123 /* Return 1 if the history is stifled, 0 if it is not. */
 124 extern int history_is_stifled PARAMS((void));
 125
 126 /* Information about the history list. */
 127
 128 /* Return a NULL terminated array of HIST_ENTRY which is the current input
 129    history.  Element 0 of this list is the beginning of time.  If there
 130    is no history, return NULL. */
 131 extern HIST_ENTRY **history_list PARAMS((void));
 132
 133 /* Returns the number which says what history element we are now
 134    looking at.  */
 135 extern int where_history PARAMS((void));
 136
 137 /* Return the history entry at the current position, as determined by
 138    history_offset.  If there is no entry there, return a NULL pointer. */
 139 extern HIST_ENTRY *current_history PARAMS((void));
 140
 141 /* Return the history entry which is logically at OFFSET in the history
 142    array.  OFFSET is relative to history_base. */
 143 extern HIST_ENTRY *history_get PARAMS((int));
 144
 145 /* Return the timestamp associated with the HIST_ENTRY * passed as an
 146    argument */
 147 extern time_t history_get_time PARAMS((HIST_ENTRY *));
 148
 149 /* Return the number of bytes that the primary history entries are using.
 150    This just adds up the lengths of the_history->lines. */
 151 extern int history_total_bytes PARAMS((void));
 152
 153 /* Moving around the history list. */
 154
 155 /* Set the position in the history list to POS. */
 156 extern int history_set_pos PARAMS((int));
 157
 158 /* Back up history_offset to the previous history entry, and return
 159    a pointer to that entry.  If there is no previous entry, return
 160    a NULL pointer. */
 161 extern HIST_ENTRY *previous_history PARAMS((void));
 162
 163 /* Move history_offset forward to the next item in the input_history,
 164    and return the a pointer to that entry.  If there is no next entry,
 165    return a NULL pointer. */
 166 extern HIST_ENTRY *next_history PARAMS((void));
 167
 168 /* Searching the history list. */
 169
 170 /* Search the history for STRING, starting at history_offset.
 171    If DIRECTION < 0, then the search is through previous entries,
 172    else through subsequent.  If the string is found, then
 173    current_history () is the history entry, and the value of this function
 174    is the offset in the line of that history entry that the string was
 175    found in.  Otherwise, nothing is changed, and a -1 is returned. */
 176 extern int history_search PARAMS((const char *, int));
 177
 178 /* Search the history for STRING, starting at history_offset.
 179    The search is anchored: matching lines must begin with string.
 180    DIRECTION is as in history_search(). */
 181 extern int history_search_prefix PARAMS((const char *, int));
 182
 183 /* Search for STRING in the history list, starting at POS, an
 184    absolute index into the list.  DIR, if negative, says to search
 185    backwards from POS, else forwards.
 186    Returns the absolute index of the history element where STRING
 187    was found, or -1 otherwise. */
 188 extern int history_search_pos PARAMS((const char *, int, int));
 189
 190 /* Managing the history file. */
 191
 192 /* Add the contents of FILENAME to the history list, a line at a time.
 193    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
 194    successful, or errno if not. */
 195 extern int read_history PARAMS((const char *));
 196
 197 /* Read a range of lines from FILENAME, adding them to the history list.
 198    Start reading at the FROM'th line and end at the TO'th.  If FROM
 199    is zero, start at the beginning.  If TO is less than FROM, read
 200    until the end of the file.  If FILENAME is NULL, then read from
 201    ~/.history.  Returns 0 if successful, or errno if not. */
 202 extern int read_history_range PARAMS((const char *, int, int));
 203
 204 /* Write the current history to FILENAME.  If FILENAME is NULL,
 205    then write the history list to ~/.history.  Values returned
 206    are as in read_history ().  */
 207 extern int write_history PARAMS((const char *));
 208
 209 /* Append NELEMENT entries to FILENAME.  The entries appended are from
 210    the end of the list minus NELEMENTs up to the end of the list. */
 211 extern int append_history PARAMS((int, const char *));
 212
 213 /* Truncate the history file, leaving only the last NLINES lines. */
 214 extern int history_truncate_file PARAMS((const char *, int));
 215
 216 /* History expansion. */
 217
 218 /* Expand the string STRING, placing the result into OUTPUT, a pointer
 219    to a string.  Returns:
 220
 221    0) If no expansions took place (or, if the only change in
 222       the text was the de-slashifying of the history expansion
 223       character)
 224    1) If expansions did take place
 225   -1) If there was an error in expansion.
 226    2) If the returned line should just be printed.
 227
 228   If an error occurred in expansion, then OUTPUT contains a descriptive
 229   error message. */
 230 extern int history_expand PARAMS((char *, char **));
 231
 232 /* Extract a string segment consisting of the FIRST through LAST
 233    arguments present in STRING.  Arguments are broken up as in
 234    the shell. */
 235 extern char *history_arg_extract PARAMS((int, int, const char *));
 236
 237 /* Return the text of the history event beginning at the current
 238    offset into STRING.  Pass STRING with *INDEX equal to the
 239    history_expansion_char that begins this specification.
 240    DELIMITING_QUOTE is a character that is allowed to end the string
 241    specification for what to search for in addition to the normal
 242    characters `:', ` ', `\t', `\n', and sometimes `?'. */
 243 extern char *get_history_event PARAMS((const char *, int *, int));
 244
 245 /* Return an array of tokens, much as the shell might.  The tokens are
 246    parsed out of STRING. */
 247 extern char **history_tokenize PARAMS((const char *));
 248
 249 /* Exported history variables. */
 250 extern int history_base;
 251 extern int history_length;
 252 extern int history_max_entries;
 253 extern int history_offset;
 254
 255 extern int history_lines_read_from_file;
 256 extern int history_lines_written_to_file;
 257
 258 extern char history_expansion_char;
 259 extern char history_subst_char;
 260 extern char *history_word_delimiters;
 261 extern char history_comment_char;
 262 extern char *history_no_expand_chars;
 263 extern char *history_search_delimiter_chars;
 264
 265 extern int history_quotes_inhibit_expansion;
 266 extern int history_quoting_state;
 267
 268 extern int history_write_timestamps;
 269
 270 /* These two are undocumented; the second is reserved for future use */
 271 extern int history_multiline_entries;
 272 extern int history_file_version;
 273
 274 /* Backwards compatibility */
 275 extern int max_input_history;
 276
 277 /* If set, this function is called to decide whether or not a particular
 278    history expansion should be treated as a special case for the calling
 279    application and not expanded. */
 280 extern rl_linebuf_func_t *history_inhibit_expansion_function;
 281
 282 #ifdef __cplusplus
 283 }
 284 #endif
 285
 286 #endif /* !_HISTORY_H_ */