Merge branch 'maint' of git://repo.or.cz/git-gui into maint
[git] / config.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  * Copyright (C) Johannes Schindelin, 2005
6  *
7  */
8 #include "cache.h"
9 #include "exec_cmd.h"
10
11 #define MAXNAME (256)
12
13 static FILE *config_file;
14 static const char *config_file_name;
15 static int config_linenr;
16 static int config_file_eof;
17 static int zlib_compression_seen;
18
19 static int get_next_char(void)
20 {
21         int c;
22         FILE *f;
23
24         c = '\n';
25         if ((f = config_file) != NULL) {
26                 c = fgetc(f);
27                 if (c == '\r') {
28                         /* DOS like systems */
29                         c = fgetc(f);
30                         if (c != '\n') {
31                                 ungetc(c, f);
32                                 c = '\r';
33                         }
34                 }
35                 if (c == '\n')
36                         config_linenr++;
37                 if (c == EOF) {
38                         config_file_eof = 1;
39                         c = '\n';
40                 }
41         }
42         return c;
43 }
44
45 static char *parse_value(void)
46 {
47         static char value[1024];
48         int quote = 0, comment = 0, len = 0, space = 0;
49
50         for (;;) {
51                 int c = get_next_char();
52                 if (len >= sizeof(value))
53                         return NULL;
54                 if (c == '\n') {
55                         if (quote)
56                                 return NULL;
57                         value[len] = 0;
58                         return value;
59                 }
60                 if (comment)
61                         continue;
62                 if (isspace(c) && !quote) {
63                         space = 1;
64                         continue;
65                 }
66                 if (!quote) {
67                         if (c == ';' || c == '#') {
68                                 comment = 1;
69                                 continue;
70                         }
71                 }
72                 if (space) {
73                         if (len)
74                                 value[len++] = ' ';
75                         space = 0;
76                 }
77                 if (c == '\\') {
78                         c = get_next_char();
79                         switch (c) {
80                         case '\n':
81                                 continue;
82                         case 't':
83                                 c = '\t';
84                                 break;
85                         case 'b':
86                                 c = '\b';
87                                 break;
88                         case 'n':
89                                 c = '\n';
90                                 break;
91                         /* Some characters escape as themselves */
92                         case '\\': case '"':
93                                 break;
94                         /* Reject unknown escape sequences */
95                         default:
96                                 return NULL;
97                         }
98                         value[len++] = c;
99                         continue;
100                 }
101                 if (c == '"') {
102                         quote = 1-quote;
103                         continue;
104                 }
105                 value[len++] = c;
106         }
107 }
108
109 static inline int iskeychar(int c)
110 {
111         return isalnum(c) || c == '-';
112 }
113
114 static int get_value(config_fn_t fn, char *name, unsigned int len)
115 {
116         int c;
117         char *value;
118
119         /* Get the full name */
120         for (;;) {
121                 c = get_next_char();
122                 if (config_file_eof)
123                         break;
124                 if (!iskeychar(c))
125                         break;
126                 name[len++] = tolower(c);
127                 if (len >= MAXNAME)
128                         return -1;
129         }
130         name[len] = 0;
131         while (c == ' ' || c == '\t')
132                 c = get_next_char();
133
134         value = NULL;
135         if (c != '\n') {
136                 if (c != '=')
137                         return -1;
138                 value = parse_value();
139                 if (!value)
140                         return -1;
141         }
142         return fn(name, value);
143 }
144
145 static int get_extended_base_var(char *name, int baselen, int c)
146 {
147         do {
148                 if (c == '\n')
149                         return -1;
150                 c = get_next_char();
151         } while (isspace(c));
152
153         /* We require the format to be '[base "extension"]' */
154         if (c != '"')
155                 return -1;
156         name[baselen++] = '.';
157
158         for (;;) {
159                 int c = get_next_char();
160                 if (c == '\n')
161                         return -1;
162                 if (c == '"')
163                         break;
164                 if (c == '\\') {
165                         c = get_next_char();
166                         if (c == '\n')
167                                 return -1;
168                 }
169                 name[baselen++] = c;
170                 if (baselen > MAXNAME / 2)
171                         return -1;
172         }
173
174         /* Final ']' */
175         if (get_next_char() != ']')
176                 return -1;
177         return baselen;
178 }
179
180 static int get_base_var(char *name)
181 {
182         int baselen = 0;
183
184         for (;;) {
185                 int c = get_next_char();
186                 if (config_file_eof)
187                         return -1;
188                 if (c == ']')
189                         return baselen;
190                 if (isspace(c))
191                         return get_extended_base_var(name, baselen, c);
192                 if (!iskeychar(c) && c != '.')
193                         return -1;
194                 if (baselen > MAXNAME / 2)
195                         return -1;
196                 name[baselen++] = tolower(c);
197         }
198 }
199
200 static int git_parse_file(config_fn_t fn)
201 {
202         int comment = 0;
203         int baselen = 0;
204         static char var[MAXNAME];
205
206         for (;;) {
207                 int c = get_next_char();
208                 if (c == '\n') {
209                         if (config_file_eof)
210                                 return 0;
211                         comment = 0;
212                         continue;
213                 }
214                 if (comment || isspace(c))
215                         continue;
216                 if (c == '#' || c == ';') {
217                         comment = 1;
218                         continue;
219                 }
220                 if (c == '[') {
221                         baselen = get_base_var(var);
222                         if (baselen <= 0)
223                                 break;
224                         var[baselen++] = '.';
225                         var[baselen] = 0;
226                         continue;
227                 }
228                 if (!isalpha(c))
229                         break;
230                 var[baselen] = tolower(c);
231                 if (get_value(fn, var, baselen+1) < 0)
232                         break;
233         }
234         die("bad config file line %d in %s", config_linenr, config_file_name);
235 }
236
237 static int parse_unit_factor(const char *end, unsigned long *val)
238 {
239         if (!*end)
240                 return 1;
241         else if (!strcasecmp(end, "k")) {
242                 *val *= 1024;
243                 return 1;
244         }
245         else if (!strcasecmp(end, "m")) {
246                 *val *= 1024 * 1024;
247                 return 1;
248         }
249         else if (!strcasecmp(end, "g")) {
250                 *val *= 1024 * 1024 * 1024;
251                 return 1;
252         }
253         return 0;
254 }
255
256 int git_parse_long(const char *value, long *ret)
257 {
258         if (value && *value) {
259                 char *end;
260                 long val = strtol(value, &end, 0);
261                 unsigned long factor = 1;
262                 if (!parse_unit_factor(end, &factor))
263                         return 0;
264                 *ret = val * factor;
265                 return 1;
266         }
267         return 0;
268 }
269
270 int git_parse_ulong(const char *value, unsigned long *ret)
271 {
272         if (value && *value) {
273                 char *end;
274                 unsigned long val = strtoul(value, &end, 0);
275                 if (!parse_unit_factor(end, &val))
276                         return 0;
277                 *ret = val;
278                 return 1;
279         }
280         return 0;
281 }
282
283 int git_config_int(const char *name, const char *value)
284 {
285         long ret;
286         if (!git_parse_long(value, &ret))
287                 die("bad config value for '%s' in %s", name, config_file_name);
288         return ret;
289 }
290
291 unsigned long git_config_ulong(const char *name, const char *value)
292 {
293         unsigned long ret;
294         if (!git_parse_ulong(value, &ret))
295                 die("bad config value for '%s' in %s", name, config_file_name);
296         return ret;
297 }
298
299 int git_config_bool(const char *name, const char *value)
300 {
301         if (!value)
302                 return 1;
303         if (!*value)
304                 return 0;
305         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
306                 return 1;
307         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
308                 return 0;
309         return git_config_int(name, value) != 0;
310 }
311
312 int git_config_string(const char **dest, const char *var, const char *value)
313 {
314         if (!value)
315                 return config_error_nonbool(var);
316         *dest = xstrdup(value);
317         return 0;
318 }
319
320 int git_default_config(const char *var, const char *value)
321 {
322         /* This needs a better name */
323         if (!strcmp(var, "core.filemode")) {
324                 trust_executable_bit = git_config_bool(var, value);
325                 return 0;
326         }
327
328         if (!strcmp(var, "core.quotepath")) {
329                 quote_path_fully = git_config_bool(var, value);
330                 return 0;
331         }
332
333         if (!strcmp(var, "core.symlinks")) {
334                 has_symlinks = git_config_bool(var, value);
335                 return 0;
336         }
337
338         if (!strcmp(var, "core.bare")) {
339                 is_bare_repository_cfg = git_config_bool(var, value);
340                 return 0;
341         }
342
343         if (!strcmp(var, "core.ignorestat")) {
344                 assume_unchanged = git_config_bool(var, value);
345                 return 0;
346         }
347
348         if (!strcmp(var, "core.prefersymlinkrefs")) {
349                 prefer_symlink_refs = git_config_bool(var, value);
350                 return 0;
351         }
352
353         if (!strcmp(var, "core.logallrefupdates")) {
354                 log_all_ref_updates = git_config_bool(var, value);
355                 return 0;
356         }
357
358         if (!strcmp(var, "core.warnambiguousrefs")) {
359                 warn_ambiguous_refs = git_config_bool(var, value);
360                 return 0;
361         }
362
363         if (!strcmp(var, "core.loosecompression")) {
364                 int level = git_config_int(var, value);
365                 if (level == -1)
366                         level = Z_DEFAULT_COMPRESSION;
367                 else if (level < 0 || level > Z_BEST_COMPRESSION)
368                         die("bad zlib compression level %d", level);
369                 zlib_compression_level = level;
370                 zlib_compression_seen = 1;
371                 return 0;
372         }
373
374         if (!strcmp(var, "core.compression")) {
375                 int level = git_config_int(var, value);
376                 if (level == -1)
377                         level = Z_DEFAULT_COMPRESSION;
378                 else if (level < 0 || level > Z_BEST_COMPRESSION)
379                         die("bad zlib compression level %d", level);
380                 core_compression_level = level;
381                 core_compression_seen = 1;
382                 if (!zlib_compression_seen)
383                         zlib_compression_level = level;
384                 return 0;
385         }
386
387         if (!strcmp(var, "core.packedgitwindowsize")) {
388                 int pgsz_x2 = getpagesize() * 2;
389                 packed_git_window_size = git_config_int(var, value);
390
391                 /* This value must be multiple of (pagesize * 2) */
392                 packed_git_window_size /= pgsz_x2;
393                 if (packed_git_window_size < 1)
394                         packed_git_window_size = 1;
395                 packed_git_window_size *= pgsz_x2;
396                 return 0;
397         }
398
399         if (!strcmp(var, "core.packedgitlimit")) {
400                 packed_git_limit = git_config_int(var, value);
401                 return 0;
402         }
403
404         if (!strcmp(var, "core.deltabasecachelimit")) {
405                 delta_base_cache_limit = git_config_int(var, value);
406                 return 0;
407         }
408
409         if (!strcmp(var, "core.autocrlf")) {
410                 if (value && !strcasecmp(value, "input")) {
411                         auto_crlf = -1;
412                         return 0;
413                 }
414                 auto_crlf = git_config_bool(var, value);
415                 return 0;
416         }
417
418         if (!strcmp(var, "user.name")) {
419                 if (!value)
420                         return config_error_nonbool(var);
421                 strlcpy(git_default_name, value, sizeof(git_default_name));
422                 return 0;
423         }
424
425         if (!strcmp(var, "user.email")) {
426                 if (!value)
427                         return config_error_nonbool(var);
428                 strlcpy(git_default_email, value, sizeof(git_default_email));
429                 return 0;
430         }
431
432         if (!strcmp(var, "i18n.commitencoding"))
433                 return git_config_string(&git_commit_encoding, var, value);
434
435         if (!strcmp(var, "i18n.logoutputencoding"))
436                 return git_config_string(&git_log_output_encoding, var, value);
437
438         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
439                 pager_use_color = git_config_bool(var,value);
440                 return 0;
441         }
442
443         if (!strcmp(var, "core.pager"))
444                 return git_config_string(&pager_program, var, value);
445
446         if (!strcmp(var, "core.editor"))
447                 return git_config_string(&editor_program, var, value);
448
449         if (!strcmp(var, "core.excludesfile"))
450                 return git_config_string(&excludes_file, var, value);
451
452         if (!strcmp(var, "core.whitespace")) {
453                 if (!value)
454                         return config_error_nonbool(var);
455                 whitespace_rule_cfg = parse_whitespace_rule(value);
456                 return 0;
457         }
458
459         /* Add other config variables here and to Documentation/config.txt. */
460         return 0;
461 }
462
463 int git_config_from_file(config_fn_t fn, const char *filename)
464 {
465         int ret;
466         FILE *f = fopen(filename, "r");
467
468         ret = -1;
469         if (f) {
470                 config_file = f;
471                 config_file_name = filename;
472                 config_linenr = 1;
473                 config_file_eof = 0;
474                 ret = git_parse_file(fn);
475                 fclose(f);
476                 config_file_name = NULL;
477         }
478         return ret;
479 }
480
481 const char *git_etc_gitconfig(void)
482 {
483         static const char *system_wide;
484         if (!system_wide) {
485                 system_wide = ETC_GITCONFIG;
486                 if (!is_absolute_path(system_wide)) {
487                         /* interpret path relative to exec-dir */
488                         const char *exec_path = git_exec_path();
489                         system_wide = prefix_path(exec_path, strlen(exec_path),
490                                                 system_wide);
491                 }
492         }
493         return system_wide;
494 }
495
496 int git_config(config_fn_t fn)
497 {
498         int ret = 0;
499         char *repo_config = NULL;
500         const char *home = NULL, *filename;
501
502         /* $GIT_CONFIG makes git read _only_ the given config file,
503          * $GIT_CONFIG_LOCAL will make it process it in addition to the
504          * global config file, the same way it would the per-repository
505          * config file otherwise. */
506         filename = getenv(CONFIG_ENVIRONMENT);
507         if (!filename) {
508                 if (!access(git_etc_gitconfig(), R_OK))
509                         ret += git_config_from_file(fn, git_etc_gitconfig());
510                 home = getenv("HOME");
511                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
512                 if (!filename)
513                         filename = repo_config = xstrdup(git_path("config"));
514         }
515
516         if (home) {
517                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
518                 if (!access(user_config, R_OK))
519                         ret = git_config_from_file(fn, user_config);
520                 free(user_config);
521         }
522
523         ret += git_config_from_file(fn, filename);
524         free(repo_config);
525         return ret;
526 }
527
528 /*
529  * Find all the stuff for git_config_set() below.
530  */
531
532 #define MAX_MATCHES 512
533
534 static struct {
535         int baselen;
536         char* key;
537         int do_not_match;
538         regex_t* value_regex;
539         int multi_replace;
540         size_t offset[MAX_MATCHES];
541         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
542         int seen;
543 } store;
544
545 static int matches(const char* key, const char* value)
546 {
547         return !strcmp(key, store.key) &&
548                 (store.value_regex == NULL ||
549                  (store.do_not_match ^
550                   !regexec(store.value_regex, value, 0, NULL, 0)));
551 }
552
553 static int store_aux(const char* key, const char* value)
554 {
555         const char *ep;
556         size_t section_len;
557
558         switch (store.state) {
559         case KEY_SEEN:
560                 if (matches(key, value)) {
561                         if (store.seen == 1 && store.multi_replace == 0) {
562                                 fprintf(stderr,
563                                         "Warning: %s has multiple values\n",
564                                         key);
565                         } else if (store.seen >= MAX_MATCHES) {
566                                 fprintf(stderr, "Too many matches\n");
567                                 return 1;
568                         }
569
570                         store.offset[store.seen] = ftell(config_file);
571                         store.seen++;
572                 }
573                 break;
574         case SECTION_SEEN:
575                 /*
576                  * What we are looking for is in store.key (both
577                  * section and var), and its section part is baselen
578                  * long.  We found key (again, both section and var).
579                  * We would want to know if this key is in the same
580                  * section as what we are looking for.  We already
581                  * know we are in the same section as what should
582                  * hold store.key.
583                  */
584                 ep = strrchr(key, '.');
585                 section_len = ep - key;
586
587                 if ((section_len != store.baselen) ||
588                     memcmp(key, store.key, section_len+1)) {
589                         store.state = SECTION_END_SEEN;
590                         break;
591                 }
592
593                 /*
594                  * Do not increment matches: this is no match, but we
595                  * just made sure we are in the desired section.
596                  */
597                 store.offset[store.seen] = ftell(config_file);
598                 /* fallthru */
599         case SECTION_END_SEEN:
600         case START:
601                 if (matches(key, value)) {
602                         store.offset[store.seen] = ftell(config_file);
603                         store.state = KEY_SEEN;
604                         store.seen++;
605                 } else {
606                         if (strrchr(key, '.') - key == store.baselen &&
607                               !strncmp(key, store.key, store.baselen)) {
608                                         store.state = SECTION_SEEN;
609                                         store.offset[store.seen] = ftell(config_file);
610                         }
611                 }
612         }
613         return 0;
614 }
615
616 static int write_error(void)
617 {
618         fprintf(stderr, "Failed to write new configuration file\n");
619
620         /* Same error code as "failed to rename". */
621         return 4;
622 }
623
624 static int store_write_section(int fd, const char* key)
625 {
626         const char *dot;
627         int i, success;
628         struct strbuf sb;
629
630         strbuf_init(&sb, 0);
631         dot = memchr(key, '.', store.baselen);
632         if (dot) {
633                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
634                 for (i = dot - key + 1; i < store.baselen; i++) {
635                         if (key[i] == '"')
636                                 strbuf_addch(&sb, '\\');
637                         strbuf_addch(&sb, key[i]);
638                 }
639                 strbuf_addstr(&sb, "\"]\n");
640         } else {
641                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
642         }
643
644         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
645         strbuf_release(&sb);
646
647         return success;
648 }
649
650 static int store_write_pair(int fd, const char* key, const char* value)
651 {
652         int i, success;
653         int length = strlen(key + store.baselen + 1);
654         const char *quote = "";
655         struct strbuf sb;
656
657         /*
658          * Check to see if the value needs to be surrounded with a dq pair.
659          * Note that problematic characters are always backslash-quoted; this
660          * check is about not losing leading or trailing SP and strings that
661          * follow beginning-of-comment characters (i.e. ';' and '#') by the
662          * configuration parser.
663          */
664         if (value[0] == ' ')
665                 quote = "\"";
666         for (i = 0; value[i]; i++)
667                 if (value[i] == ';' || value[i] == '#')
668                         quote = "\"";
669         if (i && value[i - 1] == ' ')
670                 quote = "\"";
671
672         strbuf_init(&sb, 0);
673         strbuf_addf(&sb, "\t%.*s = %s",
674                     length, key + store.baselen + 1, quote);
675
676         for (i = 0; value[i]; i++)
677                 switch (value[i]) {
678                 case '\n':
679                         strbuf_addstr(&sb, "\\n");
680                         break;
681                 case '\t':
682                         strbuf_addstr(&sb, "\\t");
683                         break;
684                 case '"':
685                 case '\\':
686                         strbuf_addch(&sb, '\\');
687                 default:
688                         strbuf_addch(&sb, value[i]);
689                         break;
690                 }
691         strbuf_addf(&sb, "%s\n", quote);
692
693         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
694         strbuf_release(&sb);
695
696         return success;
697 }
698
699 static ssize_t find_beginning_of_line(const char* contents, size_t size,
700         size_t offset_, int* found_bracket)
701 {
702         size_t equal_offset = size, bracket_offset = size;
703         ssize_t offset;
704
705 contline:
706         for (offset = offset_-2; offset > 0
707                         && contents[offset] != '\n'; offset--)
708                 switch (contents[offset]) {
709                         case '=': equal_offset = offset; break;
710                         case ']': bracket_offset = offset; break;
711                 }
712         if (offset > 0 && contents[offset-1] == '\\') {
713                 offset_ = offset;
714                 goto contline;
715         }
716         if (bracket_offset < equal_offset) {
717                 *found_bracket = 1;
718                 offset = bracket_offset+1;
719         } else
720                 offset++;
721
722         return offset;
723 }
724
725 int git_config_set(const char* key, const char* value)
726 {
727         return git_config_set_multivar(key, value, NULL, 0);
728 }
729
730 /*
731  * If value==NULL, unset in (remove from) config,
732  * if value_regex!=NULL, disregard key/value pairs where value does not match.
733  * if multi_replace==0, nothing, or only one matching key/value is replaced,
734  *     else all matching key/values (regardless how many) are removed,
735  *     before the new pair is written.
736  *
737  * Returns 0 on success.
738  *
739  * This function does this:
740  *
741  * - it locks the config file by creating ".git/config.lock"
742  *
743  * - it then parses the config using store_aux() as validator to find
744  *   the position on the key/value pair to replace. If it is to be unset,
745  *   it must be found exactly once.
746  *
747  * - the config file is mmap()ed and the part before the match (if any) is
748  *   written to the lock file, then the changed part and the rest.
749  *
750  * - the config file is removed and the lock file rename()d to it.
751  *
752  */
753 int git_config_set_multivar(const char* key, const char* value,
754         const char* value_regex, int multi_replace)
755 {
756         int i, dot;
757         int fd = -1, in_fd;
758         int ret;
759         char* config_filename;
760         struct lock_file *lock = NULL;
761         const char* last_dot = strrchr(key, '.');
762
763         config_filename = getenv(CONFIG_ENVIRONMENT);
764         if (!config_filename) {
765                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
766                 if (!config_filename)
767                         config_filename  = git_path("config");
768         }
769         config_filename = xstrdup(config_filename);
770
771         /*
772          * Since "key" actually contains the section name and the real
773          * key name separated by a dot, we have to know where the dot is.
774          */
775
776         if (last_dot == NULL) {
777                 fprintf(stderr, "key does not contain a section: %s\n", key);
778                 ret = 2;
779                 goto out_free;
780         }
781         store.baselen = last_dot - key;
782
783         store.multi_replace = multi_replace;
784
785         /*
786          * Validate the key and while at it, lower case it for matching.
787          */
788         store.key = xmalloc(strlen(key) + 1);
789         dot = 0;
790         for (i = 0; key[i]; i++) {
791                 unsigned char c = key[i];
792                 if (c == '.')
793                         dot = 1;
794                 /* Leave the extended basename untouched.. */
795                 if (!dot || i > store.baselen) {
796                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
797                                 fprintf(stderr, "invalid key: %s\n", key);
798                                 free(store.key);
799                                 ret = 1;
800                                 goto out_free;
801                         }
802                         c = tolower(c);
803                 } else if (c == '\n') {
804                         fprintf(stderr, "invalid key (newline): %s\n", key);
805                         free(store.key);
806                         ret = 1;
807                         goto out_free;
808                 }
809                 store.key[i] = c;
810         }
811         store.key[i] = 0;
812
813         /*
814          * The lock serves a purpose in addition to locking: the new
815          * contents of .git/config will be written into it.
816          */
817         lock = xcalloc(sizeof(struct lock_file), 1);
818         fd = hold_lock_file_for_update(lock, config_filename, 0);
819         if (fd < 0) {
820                 fprintf(stderr, "could not lock config file\n");
821                 free(store.key);
822                 ret = -1;
823                 goto out_free;
824         }
825
826         /*
827          * If .git/config does not exist yet, write a minimal version.
828          */
829         in_fd = open(config_filename, O_RDONLY);
830         if ( in_fd < 0 ) {
831                 free(store.key);
832
833                 if ( ENOENT != errno ) {
834                         error("opening %s: %s", config_filename,
835                               strerror(errno));
836                         ret = 3; /* same as "invalid config file" */
837                         goto out_free;
838                 }
839                 /* if nothing to unset, error out */
840                 if (value == NULL) {
841                         ret = 5;
842                         goto out_free;
843                 }
844
845                 store.key = (char*)key;
846                 if (!store_write_section(fd, key) ||
847                     !store_write_pair(fd, key, value))
848                         goto write_err_out;
849         } else {
850                 struct stat st;
851                 char* contents;
852                 size_t contents_sz, copy_begin, copy_end;
853                 int i, new_line = 0;
854
855                 if (value_regex == NULL)
856                         store.value_regex = NULL;
857                 else {
858                         if (value_regex[0] == '!') {
859                                 store.do_not_match = 1;
860                                 value_regex++;
861                         } else
862                                 store.do_not_match = 0;
863
864                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
865                         if (regcomp(store.value_regex, value_regex,
866                                         REG_EXTENDED)) {
867                                 fprintf(stderr, "Invalid pattern: %s\n",
868                                         value_regex);
869                                 free(store.value_regex);
870                                 ret = 6;
871                                 goto out_free;
872                         }
873                 }
874
875                 store.offset[0] = 0;
876                 store.state = START;
877                 store.seen = 0;
878
879                 /*
880                  * After this, store.offset will contain the *end* offset
881                  * of the last match, or remain at 0 if no match was found.
882                  * As a side effect, we make sure to transform only a valid
883                  * existing config file.
884                  */
885                 if (git_config_from_file(store_aux, config_filename)) {
886                         fprintf(stderr, "invalid config file\n");
887                         free(store.key);
888                         if (store.value_regex != NULL) {
889                                 regfree(store.value_regex);
890                                 free(store.value_regex);
891                         }
892                         ret = 3;
893                         goto out_free;
894                 }
895
896                 free(store.key);
897                 if (store.value_regex != NULL) {
898                         regfree(store.value_regex);
899                         free(store.value_regex);
900                 }
901
902                 /* if nothing to unset, or too many matches, error out */
903                 if ((store.seen == 0 && value == NULL) ||
904                                 (store.seen > 1 && multi_replace == 0)) {
905                         ret = 5;
906                         goto out_free;
907                 }
908
909                 fstat(in_fd, &st);
910                 contents_sz = xsize_t(st.st_size);
911                 contents = xmmap(NULL, contents_sz, PROT_READ,
912                         MAP_PRIVATE, in_fd, 0);
913                 close(in_fd);
914
915                 if (store.seen == 0)
916                         store.seen = 1;
917
918                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
919                         if (store.offset[i] == 0) {
920                                 store.offset[i] = copy_end = contents_sz;
921                         } else if (store.state != KEY_SEEN) {
922                                 copy_end = store.offset[i];
923                         } else
924                                 copy_end = find_beginning_of_line(
925                                         contents, contents_sz,
926                                         store.offset[i]-2, &new_line);
927
928                         if (copy_end > 0 && contents[copy_end-1] != '\n')
929                                 new_line = 1;
930
931                         /* write the first part of the config */
932                         if (copy_end > copy_begin) {
933                                 if (write_in_full(fd, contents + copy_begin,
934                                                   copy_end - copy_begin) <
935                                     copy_end - copy_begin)
936                                         goto write_err_out;
937                                 if (new_line &&
938                                     write_in_full(fd, "\n", 1) != 1)
939                                         goto write_err_out;
940                         }
941                         copy_begin = store.offset[i];
942                 }
943
944                 /* write the pair (value == NULL means unset) */
945                 if (value != NULL) {
946                         if (store.state == START) {
947                                 if (!store_write_section(fd, key))
948                                         goto write_err_out;
949                         }
950                         if (!store_write_pair(fd, key, value))
951                                 goto write_err_out;
952                 }
953
954                 /* write the rest of the config */
955                 if (copy_begin < contents_sz)
956                         if (write_in_full(fd, contents + copy_begin,
957                                           contents_sz - copy_begin) <
958                             contents_sz - copy_begin)
959                                 goto write_err_out;
960
961                 munmap(contents, contents_sz);
962         }
963
964         if (commit_lock_file(lock) < 0) {
965                 fprintf(stderr, "Cannot commit config file!\n");
966                 ret = 4;
967                 goto out_free;
968         }
969
970         /*
971          * lock is committed, so don't try to roll it back below.
972          * NOTE: Since lockfile.c keeps a linked list of all created
973          * lock_file structures, it isn't safe to free(lock).  It's
974          * better to just leave it hanging around.
975          */
976         lock = NULL;
977         ret = 0;
978
979 out_free:
980         if (lock)
981                 rollback_lock_file(lock);
982         free(config_filename);
983         return ret;
984
985 write_err_out:
986         ret = write_error();
987         goto out_free;
988
989 }
990
991 static int section_name_match (const char *buf, const char *name)
992 {
993         int i = 0, j = 0, dot = 0;
994         for (; buf[i] && buf[i] != ']'; i++) {
995                 if (!dot && isspace(buf[i])) {
996                         dot = 1;
997                         if (name[j++] != '.')
998                                 break;
999                         for (i++; isspace(buf[i]); i++)
1000                                 ; /* do nothing */
1001                         if (buf[i] != '"')
1002                                 break;
1003                         continue;
1004                 }
1005                 if (buf[i] == '\\' && dot)
1006                         i++;
1007                 else if (buf[i] == '"' && dot) {
1008                         for (i++; isspace(buf[i]); i++)
1009                                 ; /* do_nothing */
1010                         break;
1011                 }
1012                 if (buf[i] != name[j++])
1013                         break;
1014         }
1015         return (buf[i] == ']' && name[j] == 0);
1016 }
1017
1018 /* if new_name == NULL, the section is removed instead */
1019 int git_config_rename_section(const char *old_name, const char *new_name)
1020 {
1021         int ret = 0, remove = 0;
1022         char *config_filename;
1023         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1024         int out_fd;
1025         char buf[1024];
1026
1027         config_filename = getenv(CONFIG_ENVIRONMENT);
1028         if (!config_filename) {
1029                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1030                 if (!config_filename)
1031                         config_filename  = git_path("config");
1032         }
1033         config_filename = xstrdup(config_filename);
1034         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1035         if (out_fd < 0) {
1036                 ret = error("Could not lock config file!");
1037                 goto out;
1038         }
1039
1040         if (!(config_file = fopen(config_filename, "rb"))) {
1041                 /* no config file means nothing to rename, no error */
1042                 goto unlock_and_out;
1043         }
1044
1045         while (fgets(buf, sizeof(buf), config_file)) {
1046                 int i;
1047                 int length;
1048                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1049                         ; /* do nothing */
1050                 if (buf[i] == '[') {
1051                         /* it's a section */
1052                         if (section_name_match (&buf[i+1], old_name)) {
1053                                 ret++;
1054                                 if (new_name == NULL) {
1055                                         remove = 1;
1056                                         continue;
1057                                 }
1058                                 store.baselen = strlen(new_name);
1059                                 if (!store_write_section(out_fd, new_name)) {
1060                                         ret = write_error();
1061                                         goto out;
1062                                 }
1063                                 continue;
1064                         }
1065                         remove = 0;
1066                 }
1067                 if (remove)
1068                         continue;
1069                 length = strlen(buf);
1070                 if (write_in_full(out_fd, buf, length) != length) {
1071                         ret = write_error();
1072                         goto out;
1073                 }
1074         }
1075         fclose(config_file);
1076  unlock_and_out:
1077         if (commit_lock_file(lock) < 0)
1078                         ret = error("Cannot commit config file!");
1079  out:
1080         free(config_filename);
1081         return ret;
1082 }
1083
1084 /*
1085  * Call this to report error for your variable that should not
1086  * get a boolean value (i.e. "[my] var" means "true").
1087  */
1088 int config_error_nonbool(const char *var)
1089 {
1090         return error("Missing value for '%s'", var);
1091 }