submodules: ensure clean environment when operating in a submodule
[git] / git.c
1 #include "builtin.h"
2 #include "exec_cmd.h"
3 #include "cache.h"
4 #include "quote.h"
5 #include "run-command.h"
6
7 const char git_usage_string[] =
8         "git [--version] [--exec-path[=GIT_EXEC_PATH]] [--html-path]\n"
9         "           [-p|--paginate|--no-pager] [--no-replace-objects]\n"
10         "           [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE]\n"
11         "           [--help] COMMAND [ARGS]";
12
13 const char git_more_info_string[] =
14         "See 'git help COMMAND' for more information on a specific command.";
15
16 static int use_pager = -1;
17 struct pager_config {
18         const char *cmd;
19         int val;
20 };
21
22 static int pager_command_config(const char *var, const char *value, void *data)
23 {
24         struct pager_config *c = data;
25         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
26                 c->val = git_config_bool(var, value);
27         return 0;
28 }
29
30 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
31 int check_pager_config(const char *cmd)
32 {
33         struct pager_config c;
34         c.cmd = cmd;
35         c.val = -1;
36         git_config(pager_command_config, &c);
37         return c.val;
38 }
39
40 static void commit_pager_choice(void) {
41         switch (use_pager) {
42         case 0:
43                 setenv("GIT_PAGER", "cat", 1);
44                 break;
45         case 1:
46                 setup_pager();
47                 break;
48         default:
49                 break;
50         }
51 }
52
53 static int handle_options(const char ***argv, int *argc, int *envchanged)
54 {
55         int handled = 0;
56
57         while (*argc > 0) {
58                 const char *cmd = (*argv)[0];
59                 if (cmd[0] != '-')
60                         break;
61
62                 /*
63                  * For legacy reasons, the "version" and "help"
64                  * commands can be written with "--" prepended
65                  * to make them look like flags.
66                  */
67                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
68                         break;
69
70                 /*
71                  * Check remaining flags.
72                  */
73                 if (!prefixcmp(cmd, "--exec-path")) {
74                         cmd += 11;
75                         if (*cmd == '=')
76                                 git_set_argv_exec_path(cmd + 1);
77                         else {
78                                 puts(git_exec_path());
79                                 exit(0);
80                         }
81                 } else if (!strcmp(cmd, "--html-path")) {
82                         puts(system_path(GIT_HTML_PATH));
83                         exit(0);
84                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
85                         use_pager = 1;
86                 } else if (!strcmp(cmd, "--no-pager")) {
87                         use_pager = 0;
88                         if (envchanged)
89                                 *envchanged = 1;
90                 } else if (!strcmp(cmd, "--no-replace-objects")) {
91                         read_replace_refs = 0;
92                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
93                         if (envchanged)
94                                 *envchanged = 1;
95                 } else if (!strcmp(cmd, "--git-dir")) {
96                         if (*argc < 2) {
97                                 fprintf(stderr, "No directory given for --git-dir.\n" );
98                                 usage(git_usage_string);
99                         }
100                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
101                         if (envchanged)
102                                 *envchanged = 1;
103                         (*argv)++;
104                         (*argc)--;
105                         handled++;
106                 } else if (!prefixcmp(cmd, "--git-dir=")) {
107                         setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
108                         if (envchanged)
109                                 *envchanged = 1;
110                 } else if (!strcmp(cmd, "--work-tree")) {
111                         if (*argc < 2) {
112                                 fprintf(stderr, "No directory given for --work-tree.\n" );
113                                 usage(git_usage_string);
114                         }
115                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
116                         if (envchanged)
117                                 *envchanged = 1;
118                         (*argv)++;
119                         (*argc)--;
120                 } else if (!prefixcmp(cmd, "--work-tree=")) {
121                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
122                         if (envchanged)
123                                 *envchanged = 1;
124                 } else if (!strcmp(cmd, "--bare")) {
125                         static char git_dir[PATH_MAX+1];
126                         is_bare_repository_cfg = 1;
127                         setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
128                         if (envchanged)
129                                 *envchanged = 1;
130                 } else {
131                         fprintf(stderr, "Unknown option: %s\n", cmd);
132                         usage(git_usage_string);
133                 }
134
135                 (*argv)++;
136                 (*argc)--;
137                 handled++;
138         }
139         return handled;
140 }
141
142 static int handle_alias(int *argcp, const char ***argv)
143 {
144         int envchanged = 0, ret = 0, saved_errno = errno;
145         const char *subdir;
146         int count, option_count;
147         const char **new_argv;
148         const char *alias_command;
149         char *alias_string;
150         int unused_nongit;
151
152         subdir = setup_git_directory_gently(&unused_nongit);
153
154         alias_command = (*argv)[0];
155         alias_string = alias_lookup(alias_command);
156         if (alias_string) {
157                 if (alias_string[0] == '!') {
158                         if (*argcp > 1) {
159                                 struct strbuf buf;
160
161                                 strbuf_init(&buf, PATH_MAX);
162                                 strbuf_addstr(&buf, alias_string);
163                                 sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
164                                 free(alias_string);
165                                 alias_string = buf.buf;
166                         }
167                         trace_printf("trace: alias to shell cmd: %s => %s\n",
168                                      alias_command, alias_string + 1);
169                         ret = system(alias_string + 1);
170                         if (ret >= 0 && WIFEXITED(ret) &&
171                             WEXITSTATUS(ret) != 127)
172                                 exit(WEXITSTATUS(ret));
173                         die("Failed to run '%s' when expanding alias '%s'",
174                             alias_string + 1, alias_command);
175                 }
176                 count = split_cmdline(alias_string, &new_argv);
177                 if (count < 0)
178                         die("Bad alias.%s string", alias_command);
179                 option_count = handle_options(&new_argv, &count, &envchanged);
180                 if (envchanged)
181                         die("alias '%s' changes environment variables\n"
182                                  "You can use '!git' in the alias to do this.",
183                                  alias_command);
184                 memmove(new_argv - option_count, new_argv,
185                                 count * sizeof(char *));
186                 new_argv -= option_count;
187
188                 if (count < 1)
189                         die("empty alias for %s", alias_command);
190
191                 if (!strcmp(alias_command, new_argv[0]))
192                         die("recursive alias: %s", alias_command);
193
194                 trace_argv_printf(new_argv,
195                                   "trace: alias expansion: %s =>",
196                                   alias_command);
197
198                 new_argv = xrealloc(new_argv, sizeof(char *) *
199                                     (count + *argcp));
200                 /* insert after command name */
201                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
202
203                 *argv = new_argv;
204                 *argcp += count - 1;
205
206                 ret = 1;
207         }
208
209         if (subdir && chdir(subdir))
210                 die_errno("Cannot change to '%s'", subdir);
211
212         errno = saved_errno;
213
214         return ret;
215 }
216
217 const char git_version_string[] = GIT_VERSION;
218
219 #define RUN_SETUP       (1<<0)
220 #define USE_PAGER       (1<<1)
221 /*
222  * require working tree to be present -- anything uses this needs
223  * RUN_SETUP for reading from the configuration file.
224  */
225 #define NEED_WORK_TREE  (1<<2)
226
227 struct cmd_struct {
228         const char *cmd;
229         int (*fn)(int, const char **, const char *);
230         int option;
231 };
232
233 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
234 {
235         int status, help;
236         struct stat st;
237         const char *prefix;
238
239         prefix = NULL;
240         help = argc == 2 && !strcmp(argv[1], "-h");
241         if (!help) {
242                 if (p->option & RUN_SETUP)
243                         prefix = setup_git_directory();
244
245                 if (use_pager == -1 && p->option & RUN_SETUP)
246                         use_pager = check_pager_config(p->cmd);
247                 if (use_pager == -1 && p->option & USE_PAGER)
248                         use_pager = 1;
249         }
250         commit_pager_choice();
251
252         if (!help && p->option & NEED_WORK_TREE)
253                 setup_work_tree();
254
255         trace_argv_printf(argv, "trace: built-in: git");
256
257         status = p->fn(argc, argv, prefix);
258         if (status)
259                 return status;
260
261         /* Somebody closed stdout? */
262         if (fstat(fileno(stdout), &st))
263                 return 0;
264         /* Ignore write errors for pipes and sockets.. */
265         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
266                 return 0;
267
268         /* Check for ENOSPC and EIO errors.. */
269         if (fflush(stdout))
270                 die_errno("write failure on standard output");
271         if (ferror(stdout))
272                 die("unknown write failure on standard output");
273         if (fclose(stdout))
274                 die_errno("close failed on standard output");
275         return 0;
276 }
277
278 static void handle_internal_command(int argc, const char **argv)
279 {
280         const char *cmd = argv[0];
281         static struct cmd_struct commands[] = {
282                 { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
283                 { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
284                 { "annotate", cmd_annotate, RUN_SETUP },
285                 { "apply", cmd_apply },
286                 { "archive", cmd_archive },
287                 { "bisect--helper", cmd_bisect__helper, RUN_SETUP | NEED_WORK_TREE },
288                 { "blame", cmd_blame, RUN_SETUP },
289                 { "branch", cmd_branch, RUN_SETUP },
290                 { "bundle", cmd_bundle },
291                 { "cat-file", cmd_cat_file, RUN_SETUP },
292                 { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
293                 { "checkout-index", cmd_checkout_index,
294                         RUN_SETUP | NEED_WORK_TREE},
295                 { "check-ref-format", cmd_check_ref_format },
296                 { "check-attr", cmd_check_attr, RUN_SETUP },
297                 { "cherry", cmd_cherry, RUN_SETUP },
298                 { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
299                 { "clone", cmd_clone },
300                 { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
301                 { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
302                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
303                 { "config", cmd_config },
304                 { "count-objects", cmd_count_objects, RUN_SETUP },
305                 { "describe", cmd_describe, RUN_SETUP },
306                 { "diff", cmd_diff },
307                 { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
308                 { "diff-index", cmd_diff_index, RUN_SETUP },
309                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
310                 { "fast-export", cmd_fast_export, RUN_SETUP },
311                 { "fetch", cmd_fetch, RUN_SETUP },
312                 { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
313                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
314                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
315                 { "format-patch", cmd_format_patch, RUN_SETUP },
316                 { "fsck", cmd_fsck, RUN_SETUP },
317                 { "fsck-objects", cmd_fsck, RUN_SETUP },
318                 { "gc", cmd_gc, RUN_SETUP },
319                 { "get-tar-commit-id", cmd_get_tar_commit_id },
320                 { "grep", cmd_grep, USE_PAGER },
321                 { "hash-object", cmd_hash_object },
322                 { "help", cmd_help },
323                 { "index-pack", cmd_index_pack },
324                 { "init", cmd_init_db },
325                 { "init-db", cmd_init_db },
326                 { "log", cmd_log, RUN_SETUP | USE_PAGER },
327                 { "ls-files", cmd_ls_files, RUN_SETUP },
328                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
329                 { "ls-remote", cmd_ls_remote },
330                 { "mailinfo", cmd_mailinfo },
331                 { "mailsplit", cmd_mailsplit },
332                 { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
333                 { "merge-base", cmd_merge_base, RUN_SETUP },
334                 { "merge-file", cmd_merge_file },
335                 { "merge-index", cmd_merge_index, RUN_SETUP },
336                 { "merge-ours", cmd_merge_ours, RUN_SETUP },
337                 { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
338                 { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
339                 { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
340                 { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
341                 { "merge-tree", cmd_merge_tree, RUN_SETUP },
342                 { "mktag", cmd_mktag, RUN_SETUP },
343                 { "mktree", cmd_mktree, RUN_SETUP },
344                 { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
345                 { "name-rev", cmd_name_rev, RUN_SETUP },
346                 { "notes", cmd_notes, RUN_SETUP },
347                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
348                 { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
349                 { "patch-id", cmd_patch_id },
350                 { "peek-remote", cmd_ls_remote },
351                 { "pickaxe", cmd_blame, RUN_SETUP },
352                 { "prune", cmd_prune, RUN_SETUP },
353                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
354                 { "push", cmd_push, RUN_SETUP },
355                 { "read-tree", cmd_read_tree, RUN_SETUP },
356                 { "receive-pack", cmd_receive_pack },
357                 { "reflog", cmd_reflog, RUN_SETUP },
358                 { "remote", cmd_remote, RUN_SETUP },
359                 { "replace", cmd_replace, RUN_SETUP },
360                 { "repo-config", cmd_config },
361                 { "rerere", cmd_rerere, RUN_SETUP },
362                 { "reset", cmd_reset, RUN_SETUP },
363                 { "rev-list", cmd_rev_list, RUN_SETUP },
364                 { "rev-parse", cmd_rev_parse },
365                 { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
366                 { "rm", cmd_rm, RUN_SETUP },
367                 { "send-pack", cmd_send_pack, RUN_SETUP },
368                 { "shortlog", cmd_shortlog, USE_PAGER },
369                 { "show-branch", cmd_show_branch, RUN_SETUP },
370                 { "show", cmd_show, RUN_SETUP | USE_PAGER },
371                 { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
372                 { "stripspace", cmd_stripspace },
373                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
374                 { "tag", cmd_tag, RUN_SETUP },
375                 { "tar-tree", cmd_tar_tree },
376                 { "unpack-file", cmd_unpack_file, RUN_SETUP },
377                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
378                 { "update-index", cmd_update_index, RUN_SETUP },
379                 { "update-ref", cmd_update_ref, RUN_SETUP },
380                 { "update-server-info", cmd_update_server_info, RUN_SETUP },
381                 { "upload-archive", cmd_upload_archive },
382                 { "var", cmd_var },
383                 { "verify-tag", cmd_verify_tag, RUN_SETUP },
384                 { "version", cmd_version },
385                 { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
386                 { "write-tree", cmd_write_tree, RUN_SETUP },
387                 { "verify-pack", cmd_verify_pack },
388                 { "show-ref", cmd_show_ref, RUN_SETUP },
389                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
390         };
391         int i;
392         static const char ext[] = STRIP_EXTENSION;
393
394         if (sizeof(ext) > 1) {
395                 i = strlen(argv[0]) - strlen(ext);
396                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
397                         char *argv0 = xstrdup(argv[0]);
398                         argv[0] = cmd = argv0;
399                         argv0[i] = '\0';
400                 }
401         }
402
403         /* Turn "git cmd --help" into "git help cmd" */
404         if (argc > 1 && !strcmp(argv[1], "--help")) {
405                 argv[1] = argv[0];
406                 argv[0] = cmd = "help";
407         }
408
409         for (i = 0; i < ARRAY_SIZE(commands); i++) {
410                 struct cmd_struct *p = commands+i;
411                 if (strcmp(p->cmd, cmd))
412                         continue;
413                 exit(run_builtin(p, argc, argv));
414         }
415 }
416
417 static void execv_dashed_external(const char **argv)
418 {
419         struct strbuf cmd = STRBUF_INIT;
420         const char *tmp;
421         int status;
422
423         strbuf_addf(&cmd, "git-%s", argv[0]);
424
425         /*
426          * argv[0] must be the git command, but the argv array
427          * belongs to the caller, and may be reused in
428          * subsequent loop iterations. Save argv[0] and
429          * restore it on error.
430          */
431         tmp = argv[0];
432         argv[0] = cmd.buf;
433
434         trace_argv_printf(argv, "trace: exec:");
435
436         /*
437          * if we fail because the command is not found, it is
438          * OK to return. Otherwise, we just pass along the status code.
439          */
440         status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
441         if (status >= 0 || errno != ENOENT)
442                 exit(status);
443
444         argv[0] = tmp;
445
446         strbuf_release(&cmd);
447 }
448
449 static int run_argv(int *argcp, const char ***argv)
450 {
451         int done_alias = 0;
452
453         while (1) {
454                 /* See if it's an internal command */
455                 handle_internal_command(*argcp, *argv);
456
457                 /* .. then try the external ones */
458                 execv_dashed_external(*argv);
459
460                 /* It could be an alias -- this works around the insanity
461                  * of overriding "git log" with "git show" by having
462                  * alias.log = show
463                  */
464                 if (done_alias || !handle_alias(argcp, argv))
465                         break;
466                 done_alias = 1;
467         }
468
469         return done_alias;
470 }
471
472
473 int main(int argc, const char **argv)
474 {
475         const char *cmd;
476
477         cmd = git_extract_argv0_path(argv[0]);
478         if (!cmd)
479                 cmd = "git-help";
480
481         /*
482          * "git-xxxx" is the same as "git xxxx", but we obviously:
483          *
484          *  - cannot take flags in between the "git" and the "xxxx".
485          *  - cannot execute it externally (since it would just do
486          *    the same thing over again)
487          *
488          * So we just directly call the internal command handler, and
489          * die if that one cannot handle it.
490          */
491         if (!prefixcmp(cmd, "git-")) {
492                 cmd += 4;
493                 argv[0] = cmd;
494                 handle_internal_command(argc, argv);
495                 die("cannot handle %s internally", cmd);
496         }
497
498         /* Look for flags.. */
499         argv++;
500         argc--;
501         handle_options(&argv, &argc, NULL);
502         commit_pager_choice();
503         if (argc > 0) {
504                 if (!prefixcmp(argv[0], "--"))
505                         argv[0] += 2;
506         } else {
507                 /* The user didn't specify a command; give them help */
508                 printf("usage: %s\n\n", git_usage_string);
509                 list_common_cmds_help();
510                 printf("\n%s\n", git_more_info_string);
511                 exit(1);
512         }
513         cmd = argv[0];
514
515         /*
516          * We use PATH to find git commands, but we prepend some higher
517          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
518          * environment, and the $(gitexecdir) from the Makefile at build
519          * time.
520          */
521         setup_path();
522
523         while (1) {
524                 static int done_help = 0;
525                 static int was_alias = 0;
526                 was_alias = run_argv(&argc, &argv);
527                 if (errno != ENOENT)
528                         break;
529                 if (was_alias) {
530                         fprintf(stderr, "Expansion of alias '%s' failed; "
531                                 "'%s' is not a git command\n",
532                                 cmd, argv[0]);
533                         exit(1);
534                 }
535                 if (!done_help) {
536                         cmd = argv[0] = help_unknown_cmd(cmd);
537                         done_help = 1;
538                 } else
539                         break;
540         }
541
542         fprintf(stderr, "Failed to run command '%s': %s\n",
543                 cmd, strerror(errno));
544
545         return 1;
546 }