Code

git-checkout: safety check for detached HEAD checks existing refs
[git.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"
10 #define MAXNAME (256)
12 static FILE *config_file;
13 static const char *config_file_name;
14 static int config_linenr;
15 static int get_next_char(void)
16 {
17         int c;
18         FILE *f;
20         c = '\n';
21         if ((f = config_file) != NULL) {
22                 c = fgetc(f);
23                 if (c == '\r') {
24                         /* DOS like systems */
25                         c = fgetc(f);
26                         if (c != '\n') {
27                                 ungetc(c, f);
28                                 c = '\r';
29                         }
30                 }
31                 if (c == '\n')
32                         config_linenr++;
33                 if (c == EOF) {
34                         config_file = NULL;
35                         c = '\n';
36                 }
37         }
38         return c;
39 }
41 static char *parse_value(void)
42 {
43         static char value[1024];
44         int quote = 0, comment = 0, len = 0, space = 0;
46         for (;;) {
47                 int c = get_next_char();
48                 if (len >= sizeof(value))
49                         return NULL;
50                 if (c == '\n') {
51                         if (quote)
52                                 return NULL;
53                         value[len] = 0;
54                         return value;
55                 }
56                 if (comment)
57                         continue;
58                 if (isspace(c) && !quote) {
59                         space = 1;
60                         continue;
61                 }
62                 if (!quote) {
63                         if (c == ';' || c == '#') {
64                                 comment = 1;
65                                 continue;
66                         }
67                 }
68                 if (space) {
69                         if (len)
70                                 value[len++] = ' ';
71                         space = 0;
72                 }
73                 if (c == '\\') {
74                         c = get_next_char();
75                         switch (c) {
76                         case '\n':
77                                 continue;
78                         case 't':
79                                 c = '\t';
80                                 break;
81                         case 'b':
82                                 c = '\b';
83                                 break;
84                         case 'n':
85                                 c = '\n';
86                                 break;
87                         /* Some characters escape as themselves */
88                         case '\\': case '"':
89                                 break;
90                         /* Reject unknown escape sequences */
91                         default:
92                                 return NULL;
93                         }
94                         value[len++] = c;
95                         continue;
96                 }
97                 if (c == '"') {
98                         quote = 1-quote;
99                         continue;
100                 }
101                 value[len++] = c;
102         }
105 static inline int iskeychar(int c)
107         return isalnum(c) || c == '-';
110 static int get_value(config_fn_t fn, char *name, unsigned int len)
112         int c;
113         char *value;
115         /* Get the full name */
116         for (;;) {
117                 c = get_next_char();
118                 if (c == EOF)
119                         break;
120                 if (!iskeychar(c))
121                         break;
122                 name[len++] = tolower(c);
123                 if (len >= MAXNAME)
124                         return -1;
125         }
126         name[len] = 0;
127         while (c == ' ' || c == '\t')
128                 c = get_next_char();
130         value = NULL;
131         if (c != '\n') {
132                 if (c != '=')
133                         return -1;
134                 value = parse_value();
135                 if (!value)
136                         return -1;
137         }
138         return fn(name, value);
141 static int get_extended_base_var(char *name, int baselen, int c)
143         do {
144                 if (c == '\n')
145                         return -1;
146                 c = get_next_char();
147         } while (isspace(c));
149         /* We require the format to be '[base "extension"]' */
150         if (c != '"')
151                 return -1;
152         name[baselen++] = '.';
154         for (;;) {
155                 int c = get_next_char();
156                 if (c == '\n')
157                         return -1;
158                 if (c == '"')
159                         break;
160                 if (c == '\\') {
161                         c = get_next_char();
162                         if (c == '\n')
163                                 return -1;
164                 }
165                 name[baselen++] = c;
166                 if (baselen > MAXNAME / 2)
167                         return -1;
168         }
170         /* Final ']' */
171         if (get_next_char() != ']')
172                 return -1;
173         return baselen;
176 static int get_base_var(char *name)
178         int baselen = 0;
180         for (;;) {
181                 int c = get_next_char();
182                 if (c == EOF)
183                         return -1;
184                 if (c == ']')
185                         return baselen;
186                 if (isspace(c))
187                         return get_extended_base_var(name, baselen, c);
188                 if (!iskeychar(c) && c != '.')
189                         return -1;
190                 if (baselen > MAXNAME / 2)
191                         return -1;
192                 name[baselen++] = tolower(c);
193         }
196 static int git_parse_file(config_fn_t fn)
198         int comment = 0;
199         int baselen = 0;
200         static char var[MAXNAME];
202         for (;;) {
203                 int c = get_next_char();
204                 if (c == '\n') {
205                         /* EOF? */
206                         if (!config_file)
207                                 return 0;
208                         comment = 0;
209                         continue;
210                 }
211                 if (comment || isspace(c))
212                         continue;
213                 if (c == '#' || c == ';') {
214                         comment = 1;
215                         continue;
216                 }
217                 if (c == '[') {
218                         baselen = get_base_var(var);
219                         if (baselen <= 0)
220                                 break;
221                         var[baselen++] = '.';
222                         var[baselen] = 0;
223                         continue;
224                 }
225                 if (!isalpha(c))
226                         break;
227                 var[baselen] = tolower(c);
228                 if (get_value(fn, var, baselen+1) < 0)
229                         break;
230         }
231         die("bad config file line %d in %s", config_linenr, config_file_name);
234 int git_config_int(const char *name, const char *value)
236         if (value && *value) {
237                 char *end;
238                 int val = strtol(value, &end, 0);
239                 if (!*end)
240                         return val;
241                 if (!strcasecmp(end, "k"))
242                         return val * 1024;
243                 if (!strcasecmp(end, "m"))
244                         return val * 1024 * 1024;
245                 if (!strcasecmp(end, "g"))
246                         return val * 1024 * 1024 * 1024;
247         }
248         die("bad config value for '%s' in %s", name, config_file_name);
251 int git_config_bool(const char *name, const char *value)
253         if (!value)
254                 return 1;
255         if (!*value)
256                 return 0;
257         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
258                 return 1;
259         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
260                 return 0;
261         return git_config_int(name, value) != 0;
264 int git_default_config(const char *var, const char *value)
266         /* This needs a better name */
267         if (!strcmp(var, "core.filemode")) {
268                 trust_executable_bit = git_config_bool(var, value);
269                 return 0;
270         }
272         if (!strcmp(var, "core.ignorestat")) {
273                 assume_unchanged = git_config_bool(var, value);
274                 return 0;
275         }
277         if (!strcmp(var, "core.prefersymlinkrefs")) {
278                 prefer_symlink_refs = git_config_bool(var, value);
279                 return 0;
280         }
282         if (!strcmp(var, "core.logallrefupdates")) {
283                 log_all_ref_updates = git_config_bool(var, value);
284                 return 0;
285         }
287         if (!strcmp(var, "core.warnambiguousrefs")) {
288                 warn_ambiguous_refs = git_config_bool(var, value);
289                 return 0;
290         }
292         if (!strcmp(var, "core.legacyheaders")) {
293                 use_legacy_headers = git_config_bool(var, value);
294                 return 0;
295         }
297         if (!strcmp(var, "core.compression")) {
298                 int level = git_config_int(var, value);
299                 if (level == -1)
300                         level = Z_DEFAULT_COMPRESSION;
301                 else if (level < 0 || level > Z_BEST_COMPRESSION)
302                         die("bad zlib compression level %d", level);
303                 zlib_compression_level = level;
304                 return 0;
305         }
307         if (!strcmp(var, "core.packedgitwindowsize")) {
308                 int pgsz = getpagesize();
309                 packed_git_window_size = git_config_int(var, value);
310                 packed_git_window_size /= pgsz;
311                 if (packed_git_window_size < 2)
312                         packed_git_window_size = 2;
313                 packed_git_window_size *= pgsz;
314                 return 0;
315         }
317         if (!strcmp(var, "core.packedgitlimit")) {
318                 packed_git_limit = git_config_int(var, value);
319                 return 0;
320         }
322         if (!strcmp(var, "user.name")) {
323                 strlcpy(git_default_name, value, sizeof(git_default_name));
324                 return 0;
325         }
327         if (!strcmp(var, "user.email")) {
328                 strlcpy(git_default_email, value, sizeof(git_default_email));
329                 return 0;
330         }
332         if (!strcmp(var, "i18n.commitencoding")) {
333                 git_commit_encoding = strdup(value);
334                 return 0;
335         }
337         if (!strcmp(var, "i18n.logoutputencoding")) {
338                 git_log_output_encoding = strdup(value);
339                 return 0;
340         }
343         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
344                 pager_use_color = git_config_bool(var,value);
345                 return 0;
346         }
348         /* Add other config variables here and to Documentation/config.txt. */
349         return 0;
352 int git_config_from_file(config_fn_t fn, const char *filename)
354         int ret;
355         FILE *f = fopen(filename, "r");
357         ret = -1;
358         if (f) {
359                 config_file = f;
360                 config_file_name = filename;
361                 config_linenr = 1;
362                 ret = git_parse_file(fn);
363                 fclose(f);
364                 config_file_name = NULL;
365         }
366         return ret;
369 int git_config(config_fn_t fn)
371         int ret = 0;
372         char *repo_config = NULL;
373         const char *home = NULL, *filename;
375         /* $GIT_CONFIG makes git read _only_ the given config file,
376          * $GIT_CONFIG_LOCAL will make it process it in addition to the
377          * global config file, the same way it would the per-repository
378          * config file otherwise. */
379         filename = getenv(CONFIG_ENVIRONMENT);
380         if (!filename) {
381                 home = getenv("HOME");
382                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
383                 if (!filename)
384                         filename = repo_config = xstrdup(git_path("config"));
385         }
387         if (home) {
388                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
389                 if (!access(user_config, R_OK))
390                         ret = git_config_from_file(fn, user_config);
391                 free(user_config);
392         }
394         ret += git_config_from_file(fn, filename);
395         free(repo_config);
396         return ret;
399 /*
400  * Find all the stuff for git_config_set() below.
401  */
403 #define MAX_MATCHES 512
405 static struct {
406         int baselen;
407         char* key;
408         int do_not_match;
409         regex_t* value_regex;
410         int multi_replace;
411         off_t offset[MAX_MATCHES];
412         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
413         int seen;
414 } store;
416 static int matches(const char* key, const char* value)
418         return !strcmp(key, store.key) &&
419                 (store.value_regex == NULL ||
420                  (store.do_not_match ^
421                   !regexec(store.value_regex, value, 0, NULL, 0)));
424 static int store_aux(const char* key, const char* value)
426         switch (store.state) {
427         case KEY_SEEN:
428                 if (matches(key, value)) {
429                         if (store.seen == 1 && store.multi_replace == 0) {
430                                 fprintf(stderr,
431                                         "Warning: %s has multiple values\n",
432                                         key);
433                         } else if (store.seen >= MAX_MATCHES) {
434                                 fprintf(stderr, "Too many matches\n");
435                                 return 1;
436                         }
438                         store.offset[store.seen] = ftell(config_file);
439                         store.seen++;
440                 }
441                 break;
442         case SECTION_SEEN:
443                 if (strncmp(key, store.key, store.baselen+1)) {
444                         store.state = SECTION_END_SEEN;
445                         break;
446                 } else
447                         /* do not increment matches: this is no match */
448                         store.offset[store.seen] = ftell(config_file);
449                 /* fallthru */
450         case SECTION_END_SEEN:
451         case START:
452                 if (matches(key, value)) {
453                         store.offset[store.seen] = ftell(config_file);
454                         store.state = KEY_SEEN;
455                         store.seen++;
456                 } else {
457                         if (strrchr(key, '.') - key == store.baselen &&
458                               !strncmp(key, store.key, store.baselen)) {
459                                         store.state = SECTION_SEEN;
460                                         store.offset[store.seen] = ftell(config_file);
461                         }
462                 }
463         }
464         return 0;
467 static void store_write_section(int fd, const char* key)
469         const char *dot = strchr(key, '.');
470         int len1 = store.baselen, len2 = -1;
472         dot = strchr(key, '.');
473         if (dot) {
474                 int dotlen = dot - key;
475                 if (dotlen < len1) {
476                         len2 = len1 - dotlen - 1;
477                         len1 = dotlen;
478                 }
479         }
481         write(fd, "[", 1);
482         write(fd, key, len1);
483         if (len2 >= 0) {
484                 write(fd, " \"", 2);
485                 while (--len2 >= 0) {
486                         unsigned char c = *++dot;
487                         if (c == '"')
488                                 write(fd, "\\", 1);
489                         write(fd, &c, 1);
490                 }
491                 write(fd, "\"", 1);
492         }
493         write(fd, "]\n", 2);
496 static void store_write_pair(int fd, const char* key, const char* value)
498         int i;
500         write(fd, "\t", 1);
501         write(fd, key+store.baselen+1,
502                 strlen(key+store.baselen+1));
503         write(fd, " = ", 3);
504         for (i = 0; value[i]; i++)
505                 switch (value[i]) {
506                 case '\n': write(fd, "\\n", 2); break;
507                 case '\t': write(fd, "\\t", 2); break;
508                 case '"': case '\\': write(fd, "\\", 1);
509                 default: write(fd, value+i, 1);
510         }
511         write(fd, "\n", 1);
514 static int find_beginning_of_line(const char* contents, int size,
515         int offset_, int* found_bracket)
517         int equal_offset = size, bracket_offset = size;
518         int offset;
520         for (offset = offset_-2; offset > 0 
521                         && contents[offset] != '\n'; offset--)
522                 switch (contents[offset]) {
523                         case '=': equal_offset = offset; break;
524                         case ']': bracket_offset = offset; break;
525                 }
526         if (bracket_offset < equal_offset) {
527                 *found_bracket = 1;
528                 offset = bracket_offset+1;
529         } else
530                 offset++;
532         return offset;
535 int git_config_set(const char* key, const char* value)
537         return git_config_set_multivar(key, value, NULL, 0);
540 /*
541  * If value==NULL, unset in (remove from) config,
542  * if value_regex!=NULL, disregard key/value pairs where value does not match.
543  * if multi_replace==0, nothing, or only one matching key/value is replaced,
544  *     else all matching key/values (regardless how many) are removed,
545  *     before the new pair is written.
546  *
547  * Returns 0 on success.
548  *
549  * This function does this:
550  *
551  * - it locks the config file by creating ".git/config.lock"
552  *
553  * - it then parses the config using store_aux() as validator to find
554  *   the position on the key/value pair to replace. If it is to be unset,
555  *   it must be found exactly once.
556  *
557  * - the config file is mmap()ed and the part before the match (if any) is
558  *   written to the lock file, then the changed part and the rest.
559  *
560  * - the config file is removed and the lock file rename()d to it.
561  *
562  */
563 int git_config_set_multivar(const char* key, const char* value,
564         const char* value_regex, int multi_replace)
566         int i, dot;
567         int fd = -1, in_fd;
568         int ret;
569         char* config_filename;
570         char* lock_file;
571         const char* last_dot = strrchr(key, '.');
573         config_filename = getenv(CONFIG_ENVIRONMENT);
574         if (!config_filename) {
575                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
576                 if (!config_filename)
577                         config_filename  = git_path("config");
578         }
579         config_filename = xstrdup(config_filename);
580         lock_file = xstrdup(mkpath("%s.lock", config_filename));
582         /*
583          * Since "key" actually contains the section name and the real
584          * key name separated by a dot, we have to know where the dot is.
585          */
587         if (last_dot == NULL) {
588                 fprintf(stderr, "key does not contain a section: %s\n", key);
589                 ret = 2;
590                 goto out_free;
591         }
592         store.baselen = last_dot - key;
594         store.multi_replace = multi_replace;
596         /*
597          * Validate the key and while at it, lower case it for matching.
598          */
599         store.key = xmalloc(strlen(key) + 1);
600         dot = 0;
601         for (i = 0; key[i]; i++) {
602                 unsigned char c = key[i];
603                 if (c == '.')
604                         dot = 1;
605                 /* Leave the extended basename untouched.. */
606                 if (!dot || i > store.baselen) {
607                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
608                                 fprintf(stderr, "invalid key: %s\n", key);
609                                 free(store.key);
610                                 ret = 1;
611                                 goto out_free;
612                         }
613                         c = tolower(c);
614                 }
615                 store.key[i] = c;
616         }
617         store.key[i] = 0;
619         /*
620          * The lock_file serves a purpose in addition to locking: the new
621          * contents of .git/config will be written into it.
622          */
623         fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
624         if (fd < 0 || adjust_shared_perm(lock_file)) {
625                 fprintf(stderr, "could not lock config file\n");
626                 free(store.key);
627                 ret = -1;
628                 goto out_free;
629         }
631         /*
632          * If .git/config does not exist yet, write a minimal version.
633          */
634         in_fd = open(config_filename, O_RDONLY);
635         if ( in_fd < 0 ) {
636                 free(store.key);
638                 if ( ENOENT != errno ) {
639                         error("opening %s: %s", config_filename,
640                               strerror(errno));
641                         ret = 3; /* same as "invalid config file" */
642                         goto out_free;
643                 }
644                 /* if nothing to unset, error out */
645                 if (value == NULL) {
646                         ret = 5;
647                         goto out_free;
648                 }
650                 store.key = (char*)key;
651                 store_write_section(fd, key);
652                 store_write_pair(fd, key, value);
653         } else{
654                 struct stat st;
655                 char* contents;
656                 int i, copy_begin, copy_end, new_line = 0;
658                 if (value_regex == NULL)
659                         store.value_regex = NULL;
660                 else {
661                         if (value_regex[0] == '!') {
662                                 store.do_not_match = 1;
663                                 value_regex++;
664                         } else
665                                 store.do_not_match = 0;
667                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
668                         if (regcomp(store.value_regex, value_regex,
669                                         REG_EXTENDED)) {
670                                 fprintf(stderr, "Invalid pattern: %s\n",
671                                         value_regex);
672                                 free(store.value_regex);
673                                 ret = 6;
674                                 goto out_free;
675                         }
676                 }
678                 store.offset[0] = 0;
679                 store.state = START;
680                 store.seen = 0;
682                 /*
683                  * After this, store.offset will contain the *end* offset
684                  * of the last match, or remain at 0 if no match was found.
685                  * As a side effect, we make sure to transform only a valid
686                  * existing config file.
687                  */
688                 if (git_config_from_file(store_aux, config_filename)) {
689                         fprintf(stderr, "invalid config file\n");
690                         free(store.key);
691                         if (store.value_regex != NULL) {
692                                 regfree(store.value_regex);
693                                 free(store.value_regex);
694                         }
695                         ret = 3;
696                         goto out_free;
697                 }
699                 free(store.key);
700                 if (store.value_regex != NULL) {
701                         regfree(store.value_regex);
702                         free(store.value_regex);
703                 }
705                 /* if nothing to unset, or too many matches, error out */
706                 if ((store.seen == 0 && value == NULL) ||
707                                 (store.seen > 1 && multi_replace == 0)) {
708                         ret = 5;
709                         goto out_free;
710                 }
712                 fstat(in_fd, &st);
713                 contents = xmmap(NULL, st.st_size, PROT_READ,
714                         MAP_PRIVATE, in_fd, 0);
715                 close(in_fd);
717                 if (store.seen == 0)
718                         store.seen = 1;
720                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
721                         if (store.offset[i] == 0) {
722                                 store.offset[i] = copy_end = st.st_size;
723                         } else if (store.state != KEY_SEEN) {
724                                 copy_end = store.offset[i];
725                         } else
726                                 copy_end = find_beginning_of_line(
727                                         contents, st.st_size,
728                                         store.offset[i]-2, &new_line);
730                         /* write the first part of the config */
731                         if (copy_end > copy_begin) {
732                                 write(fd, contents + copy_begin,
733                                 copy_end - copy_begin);
734                                 if (new_line)
735                                         write(fd, "\n", 1);
736                         }
737                         copy_begin = store.offset[i];
738                 }
740                 /* write the pair (value == NULL means unset) */
741                 if (value != NULL) {
742                         if (store.state == START)
743                                 store_write_section(fd, key);
744                         store_write_pair(fd, key, value);
745                 }
747                 /* write the rest of the config */
748                 if (copy_begin < st.st_size)
749                         write(fd, contents + copy_begin,
750                                 st.st_size - copy_begin);
752                 munmap(contents, st.st_size);
753                 unlink(config_filename);
754         }
756         if (rename(lock_file, config_filename) < 0) {
757                 fprintf(stderr, "Could not rename the lock file?\n");
758                 ret = 4;
759                 goto out_free;
760         }
762         ret = 0;
764 out_free:
765         if (0 <= fd)
766                 close(fd);
767         free(config_filename);
768         if (lock_file) {
769                 unlink(lock_file);
770                 free(lock_file);
771         }
772         return ret;
775 int git_config_rename_section(const char *old_name, const char *new_name)
777         int ret = 0;
778         char *config_filename;
779         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
780         int out_fd;
781         char buf[1024];
783         config_filename = getenv(CONFIG_ENVIRONMENT);
784         if (!config_filename) {
785                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
786                 if (!config_filename)
787                         config_filename  = git_path("config");
788         }
789         config_filename = xstrdup(config_filename);
790         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
791         if (out_fd < 0) {
792                 ret = error("Could not lock config file!");
793                 goto out;
794         }
796         if (!(config_file = fopen(config_filename, "rb"))) {
797                 ret = error("Could not open config file!");
798                 goto out;
799         }
801         while (fgets(buf, sizeof(buf), config_file)) {
802                 int i;
803                 for (i = 0; buf[i] && isspace(buf[i]); i++)
804                         ; /* do nothing */
805                 if (buf[i] == '[') {
806                         /* it's a section */
807                         int j = 0, dot = 0;
808                         for (i++; buf[i] && buf[i] != ']'; i++) {
809                                 if (!dot && isspace(buf[i])) {
810                                         dot = 1;
811                                         if (old_name[j++] != '.')
812                                                 break;
813                                         for (i++; isspace(buf[i]); i++)
814                                                 ; /* do nothing */
815                                         if (buf[i] != '"')
816                                                 break;
817                                         continue;
818                                 }
819                                 if (buf[i] == '\\' && dot)
820                                         i++;
821                                 else if (buf[i] == '"' && dot) {
822                                         for (i++; isspace(buf[i]); i++)
823                                                 ; /* do_nothing */
824                                         break;
825                                 }
826                                 if (buf[i] != old_name[j++])
827                                         break;
828                         }
829                         if (buf[i] == ']') {
830                                 /* old_name matches */
831                                 ret++;
832                                 store.baselen = strlen(new_name);
833                                 store_write_section(out_fd, new_name);
834                                 continue;
835                         }
836                 }
837                 write(out_fd, buf, strlen(buf));
838         }
839         fclose(config_file);
840         if (close(out_fd) || commit_lock_file(lock) < 0)
841                 ret = error("Cannot commit config file!");
842  out:
843         free(config_filename);
844         return ret;