| 1 | /* histfile.c - functions to manipulate the history file. */ |
| 2 | |
| 3 | /* Copyright (C) 1989, 1992 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file contains the GNU History Library (the Library), a set of |
| 6 | routines for managing the text of previously typed lines. |
| 7 | |
| 8 | The Library 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 1, or (at your option) |
| 11 | any later version. |
| 12 | |
| 13 | The Library is distributed in the hope that it will be useful, but |
| 14 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | General Public License for more details. |
| 17 | |
| 18 | The GNU General Public License is often shipped with GNU software, and |
| 19 | is generally kept in a file called COPYING or LICENSE. If you do not |
| 20 | have a copy of the license, write to the Free Software Foundation, |
| 21 | 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 22 | |
| 23 | /* The goal is to make the implementation transparent, so that you |
| 24 | don't have to know what data types are used, just what functions |
| 25 | you can call. I think I have done that. */ |
| 26 | #define READLINE_LIBRARY |
| 27 | |
| 28 | #if defined (HAVE_CONFIG_H) |
| 29 | # include <config.h> |
| 30 | #endif |
| 31 | |
| 32 | #include <stdio.h> |
| 33 | |
| 34 | #include <sys/types.h> |
| 35 | #ifndef _MINIX |
| 36 | # include <sys/file.h> |
| 37 | #endif |
| 38 | #include <sys/stat.h> |
| 39 | #include <fcntl.h> |
| 40 | |
| 41 | #if defined (HAVE_STDLIB_H) |
| 42 | # include <stdlib.h> |
| 43 | #else |
| 44 | # include "ansi_stdlib.h" |
| 45 | #endif /* HAVE_STDLIB_H */ |
| 46 | |
| 47 | #if defined (HAVE_UNISTD_H) |
| 48 | # include <unistd.h> |
| 49 | #endif |
| 50 | |
| 51 | #if defined (HAVE_STRING_H) |
| 52 | # include <string.h> |
| 53 | #else |
| 54 | # include <strings.h> |
| 55 | #endif /* !HAVE_STRING_H */ |
| 56 | |
| 57 | #if defined (__EMX__) |
| 58 | # ifndef O_BINARY |
| 59 | # define O_BINARY 0 |
| 60 | # endif |
| 61 | #else /* !__EMX__ */ |
| 62 | /* If we're not compiling for __EMX__, we don't want this at all. Ever. */ |
| 63 | # undef O_BINARY |
| 64 | # define O_BINARY 0 |
| 65 | #endif /* !__EMX__ */ |
| 66 | |
| 67 | #include <errno.h> |
| 68 | #if !defined (errno) |
| 69 | extern int errno; |
| 70 | #endif /* !errno */ |
| 71 | |
| 72 | #include "history.h" |
| 73 | #include "histlib.h" |
| 74 | |
| 75 | /* Functions imported from shell.c */ |
| 76 | extern char *get_env_value (); |
| 77 | |
| 78 | extern char *xmalloc (), *xrealloc (); |
| 79 | |
| 80 | /* Return the string that should be used in the place of this |
| 81 | filename. This only matters when you don't specify the |
| 82 | filename to read_history (), or write_history (). */ |
| 83 | static char * |
| 84 | history_filename (filename) |
| 85 | char *filename; |
| 86 | { |
| 87 | char *return_val, *home; |
| 88 | int home_len; |
| 89 | |
| 90 | return_val = filename ? savestring (filename) : (char *)NULL; |
| 91 | |
| 92 | if (return_val) |
| 93 | return (return_val); |
| 94 | |
| 95 | home = get_env_value ("HOME"); |
| 96 | |
| 97 | if (home == 0) |
| 98 | { |
| 99 | home = "."; |
| 100 | home_len = 1; |
| 101 | } |
| 102 | else |
| 103 | home_len = strlen (home); |
| 104 | |
| 105 | return_val = xmalloc (2 + home_len + 8); /* strlen(".history") == 8 */ |
| 106 | strcpy (return_val, home); |
| 107 | return_val[home_len] = '/'; |
| 108 | strcpy (return_val + home_len + 1, ".history"); |
| 109 | |
| 110 | return (return_val); |
| 111 | } |
| 112 | |
| 113 | /* Add the contents of FILENAME to the history list, a line at a time. |
| 114 | If FILENAME is NULL, then read from ~/.history. Returns 0 if |
| 115 | successful, or errno if not. */ |
| 116 | int |
| 117 | read_history (filename) |
| 118 | char *filename; |
| 119 | { |
| 120 | return (read_history_range (filename, 0, -1)); |
| 121 | } |
| 122 | |
| 123 | /* Read a range of lines from FILENAME, adding them to the history list. |
| 124 | Start reading at the FROM'th line and end at the TO'th. If FROM |
| 125 | is zero, start at the beginning. If TO is less than FROM, read |
| 126 | until the end of the file. If FILENAME is NULL, then read from |
| 127 | ~/.history. Returns 0 if successful, or errno if not. */ |
| 128 | int |
| 129 | read_history_range (filename, from, to) |
| 130 | char *filename; |
| 131 | int from, to; |
| 132 | { |
| 133 | register int line_start, line_end; |
| 134 | char *input, *buffer; |
| 135 | int file, current_line; |
| 136 | struct stat finfo; |
| 137 | size_t file_size; |
| 138 | |
| 139 | buffer = (char *)NULL; |
| 140 | input = history_filename (filename); |
| 141 | file = open (input, O_RDONLY|O_BINARY, 0666); |
| 142 | |
| 143 | |
| 144 | #ifdef __MSDOS__ |
| 145 | /* MSDOS doesn't allow leading dots in file names. Try again |
| 146 | with the dot replaced by an underscore. */ |
| 147 | if (file < 0 && !filename) |
| 148 | { |
| 149 | input[strlen (input) - 8] = '_'; |
| 150 | file = open (input, O_RDONLY|O_BINARY, 0666); |
| 151 | } |
| 152 | #endif |
| 153 | if ((file < 0) || (fstat (file, &finfo) == -1)) |
| 154 | goto error_and_exit; |
| 155 | |
| 156 | file_size = (size_t)finfo.st_size; |
| 157 | |
| 158 | /* check for overflow on very large files */ |
| 159 | if (file_size != finfo.st_size || file_size + 1 < file_size) |
| 160 | { |
| 161 | #if defined (EFBIG) |
| 162 | errno = EFBIG; |
| 163 | #endif |
| 164 | goto error_and_exit; |
| 165 | } |
| 166 | |
| 167 | buffer = xmalloc (file_size + 1); |
| 168 | #if 0 |
| 169 | if (read (file, buffer, file_size) != file_size) |
| 170 | #else |
| 171 | if (read (file, buffer, file_size) < 0) |
| 172 | #endif |
| 173 | { |
| 174 | error_and_exit: |
| 175 | if (file >= 0) |
| 176 | close (file); |
| 177 | |
| 178 | FREE (input); |
| 179 | FREE (buffer); |
| 180 | |
| 181 | return (errno); |
| 182 | } |
| 183 | |
| 184 | close (file); |
| 185 | |
| 186 | /* Set TO to larger than end of file if negative. */ |
| 187 | if (to < 0) |
| 188 | to = file_size; |
| 189 | |
| 190 | /* Start at beginning of file, work to end. */ |
| 191 | line_start = line_end = current_line = 0; |
| 192 | |
| 193 | /* Skip lines until we are at FROM. */ |
| 194 | while (line_start < file_size && current_line < from) |
| 195 | { |
| 196 | for (line_end = line_start; line_end < file_size; line_end++) |
| 197 | if (buffer[line_end] == '\n') |
| 198 | { |
| 199 | current_line++; |
| 200 | line_start = line_end + 1; |
| 201 | if (current_line == from) |
| 202 | break; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | /* If there are lines left to gobble, then gobble them now. */ |
| 207 | for (line_end = line_start; line_end < file_size; line_end++) |
| 208 | if (buffer[line_end] == '\n') |
| 209 | { |
| 210 | buffer[line_end] = '\0'; |
| 211 | |
| 212 | if (buffer[line_start]) |
| 213 | add_history (buffer + line_start); |
| 214 | |
| 215 | current_line++; |
| 216 | |
| 217 | if (current_line >= to) |
| 218 | break; |
| 219 | |
| 220 | line_start = line_end + 1; |
| 221 | } |
| 222 | |
| 223 | FREE (input); |
| 224 | FREE (buffer); |
| 225 | |
| 226 | return (0); |
| 227 | } |
| 228 | |
| 229 | /* Truncate the history file FNAME, leaving only LINES trailing lines. |
| 230 | If FNAME is NULL, then use ~/.history. */ |
| 231 | int |
| 232 | history_truncate_file (fname, lines) |
| 233 | char *fname; |
| 234 | int lines; |
| 235 | { |
| 236 | register int i; |
| 237 | int file, chars_read; |
| 238 | char *buffer, *filename; |
| 239 | struct stat finfo; |
| 240 | size_t file_size; |
| 241 | |
| 242 | buffer = (char *)NULL; |
| 243 | filename = history_filename (fname); |
| 244 | file = open (filename, O_RDONLY|O_BINARY, 0666); |
| 245 | |
| 246 | #ifdef __MSDOS__ |
| 247 | /* MSDOS doesn't allow leading dots in file names. Try again |
| 248 | with the dot replaced by an underscore. */ |
| 249 | if (file < 0 && !fname) |
| 250 | { |
| 251 | filename[strlen (filename) - 8] = '_'; |
| 252 | file = open (filename, O_RDONLY|O_BINARY, 0666); |
| 253 | } |
| 254 | #endif |
| 255 | |
| 256 | if (file == -1 || fstat (file, &finfo) == -1) |
| 257 | goto truncate_exit; |
| 258 | |
| 259 | file_size = (size_t)finfo.st_size; |
| 260 | |
| 261 | /* check for overflow on very large files */ |
| 262 | if (file_size != finfo.st_size || file_size + 1 < file_size) |
| 263 | { |
| 264 | close (file); |
| 265 | #if defined (EFBIG) |
| 266 | errno = EFBIG; |
| 267 | #endif |
| 268 | goto truncate_exit; |
| 269 | } |
| 270 | |
| 271 | buffer = xmalloc (file_size + 1); |
| 272 | chars_read = read (file, buffer, file_size); |
| 273 | close (file); |
| 274 | |
| 275 | if (chars_read <= 0) |
| 276 | goto truncate_exit; |
| 277 | |
| 278 | /* Count backwards from the end of buffer until we have passed |
| 279 | LINES lines. */ |
| 280 | for (i = chars_read - 1; lines && i; i--) |
| 281 | { |
| 282 | if (buffer[i] == '\n') |
| 283 | lines--; |
| 284 | } |
| 285 | |
| 286 | /* If this is the first line, then the file contains exactly the |
| 287 | number of lines we want to truncate to, so we don't need to do |
| 288 | anything. It's the first line if we don't find a newline between |
| 289 | the current value of i and 0. Otherwise, write from the start of |
| 290 | this line until the end of the buffer. */ |
| 291 | for ( ; i; i--) |
| 292 | if (buffer[i] == '\n') |
| 293 | { |
| 294 | i++; |
| 295 | break; |
| 296 | } |
| 297 | |
| 298 | /* Write only if there are more lines in the file than we want to |
| 299 | truncate to. */ |
| 300 | if (i && ((file = open (filename, O_WRONLY|O_TRUNC|O_BINARY, 0600)) != -1)) |
| 301 | { |
| 302 | write (file, buffer + i, file_size - i); |
| 303 | |
| 304 | #if defined (__BEOS__) |
| 305 | /* BeOS ignores O_TRUNC. */ |
| 306 | ftruncate (file, file_size - i); |
| 307 | #endif |
| 308 | |
| 309 | close (file); |
| 310 | } |
| 311 | |
| 312 | truncate_exit: |
| 313 | |
| 314 | FREE (buffer); |
| 315 | |
| 316 | free (filename); |
| 317 | return 0; |
| 318 | } |
| 319 | |
| 320 | /* Workhorse function for writing history. Writes NELEMENT entries |
| 321 | from the history list to FILENAME. OVERWRITE is non-zero if you |
| 322 | wish to replace FILENAME with the entries. */ |
| 323 | static int |
| 324 | history_do_write (filename, nelements, overwrite) |
| 325 | char *filename; |
| 326 | int nelements, overwrite; |
| 327 | { |
| 328 | register int i; |
| 329 | char *output; |
| 330 | int file, mode; |
| 331 | |
| 332 | mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY; |
| 333 | output = history_filename (filename); |
| 334 | |
| 335 | if ((file = open (output, mode, 0600)) == -1) |
| 336 | { |
| 337 | #ifdef __MSDOS__ |
| 338 | /* MSDOS doesn't allow leading dots in file names. If this is |
| 339 | the default file name, try again with the dot replaced by an |
| 340 | underscore. */ |
| 341 | if (!filename) |
| 342 | { |
| 343 | output[strlen (output) - 8] = '_'; |
| 344 | if ((file = open (output, mode, 0600)) == -1) |
| 345 | { |
| 346 | FREE (output); |
| 347 | return (errno); |
| 348 | } |
| 349 | } |
| 350 | #else |
| 351 | FREE (output); |
| 352 | return (errno); |
| 353 | #endif |
| 354 | } |
| 355 | |
| 356 | if (nelements > history_length) |
| 357 | nelements = history_length; |
| 358 | |
| 359 | /* Build a buffer of all the lines to write, and write them in one syscall. |
| 360 | Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */ |
| 361 | { |
| 362 | HIST_ENTRY **the_history; /* local */ |
| 363 | register int j; |
| 364 | int buffer_size; |
| 365 | char *buffer; |
| 366 | |
| 367 | the_history = history_list (); |
| 368 | /* Calculate the total number of bytes to write. */ |
| 369 | for (buffer_size = 0, i = history_length - nelements; i < history_length; i++) |
| 370 | buffer_size += 1 + strlen (the_history[i]->line); |
| 371 | |
| 372 | /* Allocate the buffer, and fill it. */ |
| 373 | buffer = xmalloc (buffer_size); |
| 374 | |
| 375 | for (j = 0, i = history_length - nelements; i < history_length; i++) |
| 376 | { |
| 377 | strcpy (buffer + j, the_history[i]->line); |
| 378 | j += strlen (the_history[i]->line); |
| 379 | buffer[j++] = '\n'; |
| 380 | } |
| 381 | |
| 382 | write (file, buffer, buffer_size); |
| 383 | free (buffer); |
| 384 | } |
| 385 | |
| 386 | close (file); |
| 387 | |
| 388 | FREE (output); |
| 389 | |
| 390 | return (0); |
| 391 | } |
| 392 | |
| 393 | /* Append NELEMENT entries to FILENAME. The entries appended are from |
| 394 | the end of the list minus NELEMENTs up to the end of the list. */ |
| 395 | int |
| 396 | append_history (nelements, filename) |
| 397 | int nelements; |
| 398 | char *filename; |
| 399 | { |
| 400 | return (history_do_write (filename, nelements, HISTORY_APPEND)); |
| 401 | } |
| 402 | |
| 403 | /* Overwrite FILENAME with the current history. If FILENAME is NULL, |
| 404 | then write the history list to ~/.history. Values returned |
| 405 | are as in read_history ().*/ |
| 406 | int |
| 407 | write_history (filename) |
| 408 | char *filename; |
| 409 | { |
| 410 | return (history_do_write (filename, history_length, HISTORY_OVERWRITE)); |
| 411 | } |