Merge branch 'rs/diff'
[git] / git.c
1 #include "builtin.h"
2 #include "exec_cmd.h"
3 #include "cache.h"
4 #include "quote.h"
5
6 const char git_usage_string[] =
7         "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
8
9 static void prepend_to_path(const char *dir, int len)
10 {
11         const char *old_path = getenv("PATH");
12         char *path;
13         int path_len = len;
14
15         if (!old_path)
16                 old_path = "/usr/local/bin:/usr/bin:/bin";
17
18         path_len = len + strlen(old_path) + 1;
19
20         path = xmalloc(path_len + 1);
21
22         memcpy(path, dir, len);
23         path[len] = ':';
24         memcpy(path + len + 1, old_path, path_len - len);
25
26         setenv("PATH", path, 1);
27
28         free(path);
29 }
30
31 static int handle_options(const char*** argv, int* argc, int* envchanged)
32 {
33         int handled = 0;
34
35         while (*argc > 0) {
36                 const char *cmd = (*argv)[0];
37                 if (cmd[0] != '-')
38                         break;
39
40                 /*
41                  * For legacy reasons, the "version" and "help"
42                  * commands can be written with "--" prepended
43                  * to make them look like flags.
44                  */
45                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
46                         break;
47
48                 /*
49                  * Check remaining flags.
50                  */
51                 if (!prefixcmp(cmd, "--exec-path")) {
52                         cmd += 11;
53                         if (*cmd == '=')
54                                 git_set_exec_path(cmd + 1);
55                         else {
56                                 puts(git_exec_path());
57                                 exit(0);
58                         }
59                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
60                         setup_pager();
61                 } else if (!strcmp(cmd, "--git-dir")) {
62                         if (*argc < 2) {
63                                 fprintf(stderr, "No directory given for --git-dir.\n" );
64                                 usage(git_usage_string);
65                         }
66                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
67                         if (envchanged)
68                                 *envchanged = 1;
69                         (*argv)++;
70                         (*argc)--;
71                         handled++;
72                 } else if (!prefixcmp(cmd, "--git-dir=")) {
73                         setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
74                         if (envchanged)
75                                 *envchanged = 1;
76                 } else if (!strcmp(cmd, "--work-tree")) {
77                         if (*argc < 2) {
78                                 fprintf(stderr, "No directory given for --work-tree.\n" );
79                                 usage(git_usage_string);
80                         }
81                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
82                         if (envchanged)
83                                 *envchanged = 1;
84                         (*argv)++;
85                         (*argc)--;
86                 } else if (!prefixcmp(cmd, "--work-tree=")) {
87                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
88                         if (envchanged)
89                                 *envchanged = 1;
90                 } else if (!strcmp(cmd, "--bare")) {
91                         static char git_dir[PATH_MAX+1];
92                         setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 1);
93                         if (envchanged)
94                                 *envchanged = 1;
95                 } else {
96                         fprintf(stderr, "Unknown option: %s\n", cmd);
97                         usage(git_usage_string);
98                 }
99
100                 (*argv)++;
101                 (*argc)--;
102                 handled++;
103         }
104         return handled;
105 }
106
107 static const char *alias_command;
108 static char *alias_string;
109
110 static int git_alias_config(const char *var, const char *value)
111 {
112         if (!prefixcmp(var, "alias.") && !strcmp(var + 6, alias_command)) {
113                 alias_string = xstrdup(value);
114         }
115         return 0;
116 }
117
118 static int split_cmdline(char *cmdline, const char ***argv)
119 {
120         int src, dst, count = 0, size = 16;
121         char quoted = 0;
122
123         *argv = xmalloc(sizeof(char*) * size);
124
125         /* split alias_string */
126         (*argv)[count++] = cmdline;
127         for (src = dst = 0; cmdline[src];) {
128                 char c = cmdline[src];
129                 if (!quoted && isspace(c)) {
130                         cmdline[dst++] = 0;
131                         while (cmdline[++src]
132                                         && isspace(cmdline[src]))
133                                 ; /* skip */
134                         if (count >= size) {
135                                 size += 16;
136                                 *argv = xrealloc(*argv, sizeof(char*) * size);
137                         }
138                         (*argv)[count++] = cmdline + dst;
139                 } else if(!quoted && (c == '\'' || c == '"')) {
140                         quoted = c;
141                         src++;
142                 } else if (c == quoted) {
143                         quoted = 0;
144                         src++;
145                 } else {
146                         if (c == '\\' && quoted != '\'') {
147                                 src++;
148                                 c = cmdline[src];
149                                 if (!c) {
150                                         free(*argv);
151                                         *argv = NULL;
152                                         return error("cmdline ends with \\");
153                                 }
154                         }
155                         cmdline[dst++] = c;
156                         src++;
157                 }
158         }
159
160         cmdline[dst] = 0;
161
162         if (quoted) {
163                 free(*argv);
164                 *argv = NULL;
165                 return error("unclosed quote");
166         }
167
168         return count;
169 }
170
171 static int handle_alias(int *argcp, const char ***argv)
172 {
173         int nongit = 0, envchanged = 0, ret = 0, saved_errno = errno;
174         const char *subdir;
175         int count, option_count;
176         const char** new_argv;
177
178         subdir = setup_git_directory_gently(&nongit);
179
180         alias_command = (*argv)[0];
181         git_config(git_alias_config);
182         if (alias_string) {
183                 if (alias_string[0] == '!') {
184                         trace_printf("trace: alias to shell cmd: %s => %s\n",
185                                      alias_command, alias_string + 1);
186                         ret = system(alias_string + 1);
187                         if (ret >= 0 && WIFEXITED(ret) &&
188                             WEXITSTATUS(ret) != 127)
189                                 exit(WEXITSTATUS(ret));
190                         die("Failed to run '%s' when expanding alias '%s'\n",
191                             alias_string + 1, alias_command);
192                 }
193                 count = split_cmdline(alias_string, &new_argv);
194                 option_count = handle_options(&new_argv, &count, &envchanged);
195                 if (envchanged)
196                         die("alias '%s' changes environment variables\n"
197                                  "You can use '!git' in the alias to do this.",
198                                  alias_command);
199                 memmove(new_argv - option_count, new_argv,
200                                 count * sizeof(char *));
201                 new_argv -= option_count;
202
203                 if (count < 1)
204                         die("empty alias for %s", alias_command);
205
206                 if (!strcmp(alias_command, new_argv[0]))
207                         die("recursive alias: %s", alias_command);
208
209                 trace_argv_printf(new_argv, count,
210                                   "trace: alias expansion: %s =>",
211                                   alias_command);
212
213                 new_argv = xrealloc(new_argv, sizeof(char*) *
214                                     (count + *argcp + 1));
215                 /* insert after command name */
216                 memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
217                 new_argv[count+*argcp] = NULL;
218
219                 *argv = new_argv;
220                 *argcp += count - 1;
221
222                 ret = 1;
223         }
224
225         if (subdir)
226                 chdir(subdir);
227
228         errno = saved_errno;
229
230         return ret;
231 }
232
233 const char git_version_string[] = GIT_VERSION;
234
235 #define RUN_SETUP       (1<<0)
236 #define USE_PAGER       (1<<1)
237 /*
238  * require working tree to be present -- anything uses this needs
239  * RUN_SETUP for reading from the configuration file.
240  */
241 #define NEED_WORK_TREE  (1<<2)
242
243 struct cmd_struct {
244         const char *cmd;
245         int (*fn)(int, const char **, const char *);
246         int option;
247 };
248
249 static int run_command(struct cmd_struct *p, int argc, const char **argv)
250 {
251         int status;
252         struct stat st;
253         const char *prefix;
254
255         prefix = NULL;
256         if (p->option & RUN_SETUP)
257                 prefix = setup_git_directory();
258         if (p->option & USE_PAGER)
259                 setup_pager();
260         if ((p->option & NEED_WORK_TREE) &&
261             (!is_inside_work_tree() || is_inside_git_dir()))
262                 die("%s must be run in a work tree", p->cmd);
263         trace_argv_printf(argv, argc, "trace: built-in: git");
264
265         status = p->fn(argc, argv, prefix);
266         if (status)
267                 return status;
268
269         /* Somebody closed stdout? */
270         if (fstat(fileno(stdout), &st))
271                 return 0;
272         /* Ignore write errors for pipes and sockets.. */
273         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
274                 return 0;
275
276         /* Check for ENOSPC and EIO errors.. */
277         if (fflush(stdout))
278                 die("write failure on standard output: %s", strerror(errno));
279         if (ferror(stdout))
280                 die("unknown write failure on standard output");
281         if (fclose(stdout))
282                 die("close failed on standard output: %s", strerror(errno));
283         return 0;
284 }
285
286 static void handle_internal_command(int argc, const char **argv)
287 {
288         const char *cmd = argv[0];
289         static struct cmd_struct commands[] = {
290                 { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
291                 { "annotate", cmd_annotate, RUN_SETUP | USE_PAGER },
292                 { "apply", cmd_apply },
293                 { "archive", cmd_archive },
294                 { "blame", cmd_blame, RUN_SETUP },
295                 { "branch", cmd_branch, RUN_SETUP },
296                 { "bundle", cmd_bundle },
297                 { "cat-file", cmd_cat_file, RUN_SETUP },
298                 { "checkout-index", cmd_checkout_index, RUN_SETUP },
299                 { "check-ref-format", cmd_check_ref_format },
300                 { "check-attr", cmd_check_attr, RUN_SETUP | NEED_WORK_TREE },
301                 { "cherry", cmd_cherry, RUN_SETUP },
302                 { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
303                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
304                 { "config", cmd_config },
305                 { "count-objects", cmd_count_objects, RUN_SETUP },
306                 { "describe", cmd_describe, RUN_SETUP },
307                 { "diff", cmd_diff, USE_PAGER },
308                 { "diff-files", cmd_diff_files },
309                 { "diff-index", cmd_diff_index, RUN_SETUP },
310                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
311                 { "fetch--tool", cmd_fetch__tool, RUN_SETUP },
312                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
313                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
314                 { "format-patch", cmd_format_patch, RUN_SETUP },
315                 { "fsck", cmd_fsck, RUN_SETUP },
316                 { "fsck-objects", cmd_fsck, RUN_SETUP },
317                 { "gc", cmd_gc, RUN_SETUP },
318                 { "get-tar-commit-id", cmd_get_tar_commit_id },
319                 { "grep", cmd_grep, RUN_SETUP | USE_PAGER },
320                 { "help", cmd_help },
321                 { "init", cmd_init_db },
322                 { "init-db", cmd_init_db },
323                 { "log", cmd_log, RUN_SETUP | USE_PAGER },
324                 { "ls-files", cmd_ls_files, RUN_SETUP },
325                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
326                 { "mailinfo", cmd_mailinfo },
327                 { "mailsplit", cmd_mailsplit },
328                 { "merge-base", cmd_merge_base, RUN_SETUP },
329                 { "merge-file", cmd_merge_file },
330                 { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
331                 { "name-rev", cmd_name_rev, RUN_SETUP },
332                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
333                 { "pickaxe", cmd_blame, RUN_SETUP | USE_PAGER },
334                 { "prune", cmd_prune, RUN_SETUP },
335                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
336                 { "push", cmd_push, RUN_SETUP },
337                 { "read-tree", cmd_read_tree, RUN_SETUP },
338                 { "reflog", cmd_reflog, RUN_SETUP },
339                 { "repo-config", cmd_config },
340                 { "rerere", cmd_rerere, RUN_SETUP },
341                 { "rev-list", cmd_rev_list, RUN_SETUP },
342                 { "rev-parse", cmd_rev_parse, RUN_SETUP },
343                 { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
344                 { "rm", cmd_rm, RUN_SETUP | NEED_WORK_TREE },
345                 { "runstatus", cmd_runstatus, RUN_SETUP | NEED_WORK_TREE },
346                 { "shortlog", cmd_shortlog, RUN_SETUP | USE_PAGER },
347                 { "show-branch", cmd_show_branch, RUN_SETUP },
348                 { "show", cmd_show, RUN_SETUP | USE_PAGER },
349                 { "stripspace", cmd_stripspace },
350                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
351                 { "tar-tree", cmd_tar_tree },
352                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
353                 { "update-index", cmd_update_index, RUN_SETUP },
354                 { "update-ref", cmd_update_ref, RUN_SETUP },
355                 { "upload-archive", cmd_upload_archive },
356                 { "version", cmd_version },
357                 { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
358                 { "write-tree", cmd_write_tree, RUN_SETUP },
359                 { "verify-pack", cmd_verify_pack },
360                 { "show-ref", cmd_show_ref, RUN_SETUP },
361                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
362         };
363         int i;
364
365         /* Turn "git cmd --help" into "git help cmd" */
366         if (argc > 1 && !strcmp(argv[1], "--help")) {
367                 argv[1] = argv[0];
368                 argv[0] = cmd = "help";
369         }
370
371         for (i = 0; i < ARRAY_SIZE(commands); i++) {
372                 struct cmd_struct *p = commands+i;
373                 if (strcmp(p->cmd, cmd))
374                         continue;
375                 exit(run_command(p, argc, argv));
376         }
377 }
378
379 int main(int argc, const char **argv)
380 {
381         const char *cmd = argv[0] ? argv[0] : "git-help";
382         char *slash = strrchr(cmd, '/');
383         const char *exec_path = NULL;
384         int done_alias = 0;
385
386         /*
387          * Take the basename of argv[0] as the command
388          * name, and the dirname as the default exec_path
389          * if it's an absolute path and we don't have
390          * anything better.
391          */
392         if (slash) {
393                 *slash++ = 0;
394                 if (*cmd == '/')
395                         exec_path = cmd;
396                 cmd = slash;
397         }
398
399         /*
400          * "git-xxxx" is the same as "git xxxx", but we obviously:
401          *
402          *  - cannot take flags in between the "git" and the "xxxx".
403          *  - cannot execute it externally (since it would just do
404          *    the same thing over again)
405          *
406          * So we just directly call the internal command handler, and
407          * die if that one cannot handle it.
408          */
409         if (!prefixcmp(cmd, "git-")) {
410                 cmd += 4;
411                 argv[0] = cmd;
412                 handle_internal_command(argc, argv);
413                 die("cannot handle %s internally", cmd);
414         }
415
416         /* Look for flags.. */
417         argv++;
418         argc--;
419         handle_options(&argv, &argc, NULL);
420         if (argc > 0) {
421                 if (!prefixcmp(argv[0], "--"))
422                         argv[0] += 2;
423         } else {
424                 /* Default command: "help" */
425                 argv[0] = "help";
426                 argc = 1;
427         }
428         cmd = argv[0];
429
430         /*
431          * We search for git commands in the following order:
432          *  - git_exec_path()
433          *  - the path of the "git" command if we could find it
434          *    in $0
435          *  - the regular PATH.
436          */
437         if (exec_path)
438                 prepend_to_path(exec_path, strlen(exec_path));
439         exec_path = git_exec_path();
440         prepend_to_path(exec_path, strlen(exec_path));
441
442         while (1) {
443                 /* See if it's an internal command */
444                 handle_internal_command(argc, argv);
445
446                 /* .. then try the external ones */
447                 execv_git_cmd(argv);
448
449                 /* It could be an alias -- this works around the insanity
450                  * of overriding "git log" with "git show" by having
451                  * alias.log = show
452                  */
453                 if (done_alias || !handle_alias(&argc, &argv))
454                         break;
455                 done_alias = 1;
456         }
457
458         if (errno == ENOENT) {
459                 if (done_alias) {
460                         fprintf(stderr, "Expansion of alias '%s' failed; "
461                                 "'%s' is not a git-command\n",
462                                 cmd, argv[0]);
463                         exit(1);
464                 }
465                 help_unknown_cmd(cmd);
466         }
467
468         fprintf(stderr, "Failed to run command '%s': %s\n",
469                 cmd, strerror(errno));
470
471         return 1;
472 }