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d60d9f65 SS |
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 | if ((file < 0) || (fstat (file, &finfo) == -1)) | |
144 | goto error_and_exit; | |
145 | ||
146 | file_size = (size_t)finfo.st_size; | |
147 | ||
148 | /* check for overflow on very large files */ | |
149 | if (file_size != finfo.st_size || file_size + 1 < file_size) | |
150 | { | |
151 | #if defined (EFBIG) | |
152 | errno = EFBIG; | |
153 | #endif | |
154 | goto error_and_exit; | |
155 | } | |
156 | ||
157 | buffer = xmalloc (file_size + 1); | |
c862e87b | 158 | #if 0 |
d60d9f65 | 159 | if (read (file, buffer, file_size) != file_size) |
c862e87b JM |
160 | #else |
161 | if (read (file, buffer, file_size) < 0) | |
162 | #endif | |
d60d9f65 SS |
163 | { |
164 | error_and_exit: | |
165 | if (file >= 0) | |
166 | close (file); | |
167 | ||
168 | FREE (input); | |
169 | FREE (buffer); | |
170 | ||
171 | return (errno); | |
172 | } | |
173 | ||
174 | close (file); | |
175 | ||
176 | /* Set TO to larger than end of file if negative. */ | |
177 | if (to < 0) | |
178 | to = file_size; | |
179 | ||
180 | /* Start at beginning of file, work to end. */ | |
181 | line_start = line_end = current_line = 0; | |
182 | ||
183 | /* Skip lines until we are at FROM. */ | |
184 | while (line_start < file_size && current_line < from) | |
185 | { | |
186 | for (line_end = line_start; line_end < file_size; line_end++) | |
187 | if (buffer[line_end] == '\n') | |
188 | { | |
189 | current_line++; | |
190 | line_start = line_end + 1; | |
191 | if (current_line == from) | |
192 | break; | |
193 | } | |
194 | } | |
195 | ||
196 | /* If there are lines left to gobble, then gobble them now. */ | |
197 | for (line_end = line_start; line_end < file_size; line_end++) | |
198 | if (buffer[line_end] == '\n') | |
199 | { | |
200 | buffer[line_end] = '\0'; | |
201 | ||
202 | if (buffer[line_start]) | |
203 | add_history (buffer + line_start); | |
204 | ||
205 | current_line++; | |
206 | ||
207 | if (current_line >= to) | |
208 | break; | |
209 | ||
210 | line_start = line_end + 1; | |
211 | } | |
212 | ||
213 | FREE (input); | |
214 | FREE (buffer); | |
215 | ||
216 | return (0); | |
217 | } | |
218 | ||
219 | /* Truncate the history file FNAME, leaving only LINES trailing lines. | |
220 | If FNAME is NULL, then use ~/.history. */ | |
221 | int | |
222 | history_truncate_file (fname, lines) | |
223 | char *fname; | |
c862e87b | 224 | int lines; |
d60d9f65 SS |
225 | { |
226 | register int i; | |
227 | int file, chars_read; | |
228 | char *buffer, *filename; | |
229 | struct stat finfo; | |
230 | size_t file_size; | |
231 | ||
232 | buffer = (char *)NULL; | |
233 | filename = history_filename (fname); | |
234 | file = open (filename, O_RDONLY|O_BINARY, 0666); | |
235 | ||
236 | if (file == -1 || fstat (file, &finfo) == -1) | |
237 | goto truncate_exit; | |
238 | ||
239 | file_size = (size_t)finfo.st_size; | |
240 | ||
241 | /* check for overflow on very large files */ | |
242 | if (file_size != finfo.st_size || file_size + 1 < file_size) | |
243 | { | |
244 | close (file); | |
245 | #if defined (EFBIG) | |
246 | errno = EFBIG; | |
247 | #endif | |
248 | goto truncate_exit; | |
249 | } | |
250 | ||
251 | buffer = xmalloc (file_size + 1); | |
252 | chars_read = read (file, buffer, file_size); | |
253 | close (file); | |
254 | ||
255 | if (chars_read <= 0) | |
256 | goto truncate_exit; | |
257 | ||
258 | /* Count backwards from the end of buffer until we have passed | |
259 | LINES lines. */ | |
260 | for (i = chars_read - 1; lines && i; i--) | |
261 | { | |
262 | if (buffer[i] == '\n') | |
263 | lines--; | |
264 | } | |
265 | ||
266 | /* If this is the first line, then the file contains exactly the | |
267 | number of lines we want to truncate to, so we don't need to do | |
268 | anything. It's the first line if we don't find a newline between | |
269 | the current value of i and 0. Otherwise, write from the start of | |
270 | this line until the end of the buffer. */ | |
271 | for ( ; i; i--) | |
272 | if (buffer[i] == '\n') | |
273 | { | |
274 | i++; | |
275 | break; | |
276 | } | |
277 | ||
278 | /* Write only if there are more lines in the file than we want to | |
279 | truncate to. */ | |
280 | if (i && ((file = open (filename, O_WRONLY|O_TRUNC|O_BINARY, 0600)) != -1)) | |
281 | { | |
282 | write (file, buffer + i, file_size - i); | |
c862e87b JM |
283 | |
284 | #if defined (__BEOS__) | |
285 | /* BeOS ignores O_TRUNC. */ | |
286 | ftruncate (file, file_size - i); | |
287 | #endif | |
288 | ||
d60d9f65 SS |
289 | close (file); |
290 | } | |
291 | ||
292 | truncate_exit: | |
293 | ||
294 | FREE (buffer); | |
295 | ||
296 | free (filename); | |
297 | return 0; | |
298 | } | |
299 | ||
300 | /* Workhorse function for writing history. Writes NELEMENT entries | |
301 | from the history list to FILENAME. OVERWRITE is non-zero if you | |
302 | wish to replace FILENAME with the entries. */ | |
303 | static int | |
304 | history_do_write (filename, nelements, overwrite) | |
305 | char *filename; | |
306 | int nelements, overwrite; | |
307 | { | |
308 | register int i; | |
309 | char *output; | |
310 | int file, mode; | |
311 | ||
312 | mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY; | |
313 | output = history_filename (filename); | |
314 | ||
315 | if ((file = open (output, mode, 0600)) == -1) | |
316 | { | |
317 | FREE (output); | |
318 | return (errno); | |
319 | } | |
320 | ||
321 | if (nelements > history_length) | |
322 | nelements = history_length; | |
323 | ||
324 | /* Build a buffer of all the lines to write, and write them in one syscall. | |
325 | Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */ | |
326 | { | |
327 | HIST_ENTRY **the_history; /* local */ | |
328 | register int j; | |
329 | int buffer_size; | |
330 | char *buffer; | |
331 | ||
332 | the_history = history_list (); | |
333 | /* Calculate the total number of bytes to write. */ | |
334 | for (buffer_size = 0, i = history_length - nelements; i < history_length; i++) | |
335 | buffer_size += 1 + strlen (the_history[i]->line); | |
336 | ||
337 | /* Allocate the buffer, and fill it. */ | |
338 | buffer = xmalloc (buffer_size); | |
339 | ||
340 | for (j = 0, i = history_length - nelements; i < history_length; i++) | |
341 | { | |
342 | strcpy (buffer + j, the_history[i]->line); | |
343 | j += strlen (the_history[i]->line); | |
344 | buffer[j++] = '\n'; | |
345 | } | |
346 | ||
347 | write (file, buffer, buffer_size); | |
348 | free (buffer); | |
349 | } | |
350 | ||
351 | close (file); | |
352 | ||
353 | FREE (output); | |
354 | ||
355 | return (0); | |
356 | } | |
357 | ||
358 | /* Append NELEMENT entries to FILENAME. The entries appended are from | |
359 | the end of the list minus NELEMENTs up to the end of the list. */ | |
360 | int | |
361 | append_history (nelements, filename) | |
362 | int nelements; | |
363 | char *filename; | |
364 | { | |
365 | return (history_do_write (filename, nelements, HISTORY_APPEND)); | |
366 | } | |
367 | ||
368 | /* Overwrite FILENAME with the current history. If FILENAME is NULL, | |
369 | then write the history list to ~/.history. Values returned | |
370 | are as in read_history ().*/ | |
371 | int | |
372 | write_history (filename) | |
373 | char *filename; | |
374 | { | |
375 | return (history_do_write (filename, history_length, HISTORY_OVERWRITE)); | |
376 | } |