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