Merge branch 'jc/diff--cached'
[git] / git.c
1 #include <stdio.h>
2 #include <sys/types.h>
3 #include <sys/stat.h>
4 #include <dirent.h>
5 #include <unistd.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <errno.h>
9 #include <limits.h>
10 #include <stdarg.h>
11 #include "git-compat-util.h"
12 #include "exec_cmd.h"
13 #include "cache.h"
14 #include "quote.h"
15
16 #include "builtin.h"
17
18 const char git_usage_string[] =
19         "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate] [--bare] [--git-dir=GIT_DIR] [--help] COMMAND [ARGS]";
20
21 static void prepend_to_path(const char *dir, int len)
22 {
23         const char *old_path = getenv("PATH");
24         char *path;
25         int path_len = len;
26
27         if (!old_path)
28                 old_path = "/usr/local/bin:/usr/bin:/bin";
29
30         path_len = len + strlen(old_path) + 1;
31
32         path = xmalloc(path_len + 1);
33
34         memcpy(path, dir, len);
35         path[len] = ':';
36         memcpy(path + len + 1, old_path, path_len - len);
37
38         setenv("PATH", path, 1);
39
40         free(path);
41 }
42
43 static int handle_options(const char*** argv, int* argc)
44 {
45         int handled = 0;
46
47         while (*argc > 0) {
48                 const char *cmd = (*argv)[0];
49                 if (cmd[0] != '-')
50                         break;
51
52                 /*
53                  * For legacy reasons, the "version" and "help"
54                  * commands can be written with "--" prepended
55                  * to make them look like flags.
56                  */
57                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
58                         break;
59
60                 /*
61                  * Check remaining flags.
62                  */
63                 if (!strncmp(cmd, "--exec-path", 11)) {
64                         cmd += 11;
65                         if (*cmd == '=')
66                                 git_set_exec_path(cmd + 1);
67                         else {
68                                 puts(git_exec_path());
69                                 exit(0);
70                         }
71                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
72                         setup_pager();
73                 } else if (!strcmp(cmd, "--git-dir")) {
74                         if (*argc < 1)
75                                 return -1;
76                         setenv("GIT_DIR", (*argv)[1], 1);
77                         (*argv)++;
78                         (*argc)--;
79                 } else if (!strncmp(cmd, "--git-dir=", 10)) {
80                         setenv("GIT_DIR", cmd + 10, 1);
81                 } else if (!strcmp(cmd, "--bare")) {
82                         static char git_dir[1024];
83                         setenv("GIT_DIR", getcwd(git_dir, 1024), 1);
84                 } else {
85                         fprintf(stderr, "Unknown option: %s\n", cmd);
86                         usage(git_usage_string);
87                 }
88
89                 (*argv)++;
90                 (*argc)--;
91                 handled++;
92         }
93         return handled;
94 }
95
96 static const char *alias_command;
97 static char *alias_string;
98
99 static int git_alias_config(const char *var, const char *value)
100 {
101         if (!strncmp(var, "alias.", 6) && !strcmp(var + 6, alias_command)) {
102                 alias_string = xstrdup(value);
103         }
104         return 0;
105 }
106
107 static int split_cmdline(char *cmdline, const char ***argv)
108 {
109         int src, dst, count = 0, size = 16;
110         char quoted = 0;
111
112         *argv = malloc(sizeof(char*) * size);
113
114         /* split alias_string */
115         (*argv)[count++] = cmdline;
116         for (src = dst = 0; cmdline[src];) {
117                 char c = cmdline[src];
118                 if (!quoted && isspace(c)) {
119                         cmdline[dst++] = 0;
120                         while (cmdline[++src]
121                                         && isspace(cmdline[src]))
122                                 ; /* skip */
123                         if (count >= size) {
124                                 size += 16;
125                                 *argv = xrealloc(*argv, sizeof(char*) * size);
126                         }
127                         (*argv)[count++] = cmdline + dst;
128                 } else if(!quoted && (c == '\'' || c == '"')) {
129                         quoted = c;
130                         src++;
131                 } else if (c == quoted) {
132                         quoted = 0;
133                         src++;
134                 } else {
135                         if (c == '\\' && quoted != '\'') {
136                                 src++;
137                                 c = cmdline[src];
138                                 if (!c) {
139                                         free(*argv);
140                                         *argv = NULL;
141                                         return error("cmdline ends with \\");
142                                 }
143                         }
144                         cmdline[dst++] = c;
145                         src++;
146                 }
147         }
148
149         cmdline[dst] = 0;
150
151         if (quoted) {
152                 free(*argv);
153                 *argv = NULL;
154                 return error("unclosed quote");
155         }
156
157         return count;
158 }
159
160 static int handle_alias(int *argcp, const char ***argv)
161 {
162         int nongit = 0, ret = 0, saved_errno = errno;
163         const char *subdir;
164         int count, option_count;
165         const char** new_argv;
166
167         subdir = setup_git_directory_gently(&nongit);
168
169         alias_command = (*argv)[0];
170         git_config(git_alias_config);
171         if (alias_string) {
172                 count = split_cmdline(alias_string, &new_argv);
173                 option_count = handle_options(&new_argv, &count);
174                 memmove(new_argv - option_count, new_argv,
175                                 count * sizeof(char *));
176                 new_argv -= option_count;
177
178                 if (count < 1)
179                         die("empty alias for %s", alias_command);
180
181                 if (!strcmp(alias_command, new_argv[0]))
182                         die("recursive alias: %s", alias_command);
183
184                 trace_argv_printf(new_argv, count,
185                                   "trace: alias expansion: %s =>",
186                                   alias_command);
187
188                 new_argv = xrealloc(new_argv, sizeof(char*) *
189                                     (count + *argcp + 1));
190                 /* insert after command name */
191                 memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
192                 new_argv[count+*argcp] = NULL;
193
194                 *argv = new_argv;
195                 *argcp += count - 1;
196
197                 ret = 1;
198         }
199
200         if (subdir)
201                 chdir(subdir);
202
203         errno = saved_errno;
204
205         return ret;
206 }
207
208 const char git_version_string[] = GIT_VERSION;
209
210 #define RUN_SETUP       (1<<0)
211 #define USE_PAGER       (1<<1)
212
213 static void handle_internal_command(int argc, const char **argv, char **envp)
214 {
215         const char *cmd = argv[0];
216         static struct cmd_struct {
217                 const char *cmd;
218                 int (*fn)(int, const char **, const char *);
219                 int option;
220         } commands[] = {
221                 { "add", cmd_add, RUN_SETUP },
222                 { "annotate", cmd_annotate, },
223                 { "apply", cmd_apply },
224                 { "archive", cmd_archive },
225                 { "blame", cmd_blame, RUN_SETUP | USE_PAGER },
226                 { "branch", cmd_branch, RUN_SETUP },
227                 { "cat-file", cmd_cat_file, RUN_SETUP },
228                 { "checkout-index", cmd_checkout_index, RUN_SETUP },
229                 { "check-ref-format", cmd_check_ref_format },
230                 { "cherry", cmd_cherry, RUN_SETUP },
231                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
232                 { "count-objects", cmd_count_objects, RUN_SETUP },
233                 { "diff", cmd_diff, RUN_SETUP | USE_PAGER },
234                 { "diff-files", cmd_diff_files, RUN_SETUP },
235                 { "diff-index", cmd_diff_index, RUN_SETUP },
236                 { "diff-stages", cmd_diff_stages, RUN_SETUP },
237                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
238                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
239                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
240                 { "format-patch", cmd_format_patch, RUN_SETUP },
241                 { "get-tar-commit-id", cmd_get_tar_commit_id },
242                 { "grep", cmd_grep, RUN_SETUP },
243                 { "help", cmd_help },
244                 { "init-db", cmd_init_db },
245                 { "log", cmd_log, RUN_SETUP | USE_PAGER },
246                 { "ls-files", cmd_ls_files, RUN_SETUP },
247                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
248                 { "mailinfo", cmd_mailinfo },
249                 { "mailsplit", cmd_mailsplit },
250                 { "merge-file", cmd_merge_file },
251                 { "mv", cmd_mv, RUN_SETUP },
252                 { "name-rev", cmd_name_rev, RUN_SETUP },
253                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
254                 { "pickaxe", cmd_blame, RUN_SETUP | USE_PAGER },
255                 { "prune", cmd_prune, RUN_SETUP },
256                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
257                 { "push", cmd_push, RUN_SETUP },
258                 { "read-tree", cmd_read_tree, RUN_SETUP },
259                 { "repo-config", cmd_repo_config },
260                 { "rev-list", cmd_rev_list, RUN_SETUP },
261                 { "rev-parse", cmd_rev_parse, RUN_SETUP },
262                 { "rm", cmd_rm, RUN_SETUP },
263                 { "runstatus", cmd_runstatus, RUN_SETUP },
264                 { "shortlog", cmd_shortlog, RUN_SETUP | USE_PAGER },
265                 { "show-branch", cmd_show_branch, RUN_SETUP },
266                 { "show", cmd_show, RUN_SETUP | USE_PAGER },
267                 { "stripspace", cmd_stripspace },
268                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
269                 { "tar-tree", cmd_tar_tree },
270                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
271                 { "update-index", cmd_update_index, RUN_SETUP },
272                 { "update-ref", cmd_update_ref, RUN_SETUP },
273                 { "upload-archive", cmd_upload_archive },
274                 { "version", cmd_version },
275                 { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
276                 { "write-tree", cmd_write_tree, RUN_SETUP },
277                 { "verify-pack", cmd_verify_pack },
278                 { "show-ref", cmd_show_ref, RUN_SETUP },
279                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
280         };
281         int i;
282
283         /* Turn "git cmd --help" into "git help cmd" */
284         if (argc > 1 && !strcmp(argv[1], "--help")) {
285                 argv[1] = argv[0];
286                 argv[0] = cmd = "help";
287         }
288
289         for (i = 0; i < ARRAY_SIZE(commands); i++) {
290                 struct cmd_struct *p = commands+i;
291                 const char *prefix;
292                 if (strcmp(p->cmd, cmd))
293                         continue;
294
295                 prefix = NULL;
296                 if (p->option & RUN_SETUP)
297                         prefix = setup_git_directory();
298                 if (p->option & USE_PAGER)
299                         setup_pager();
300                 trace_argv_printf(argv, argc, "trace: built-in: git");
301
302                 exit(p->fn(argc, argv, prefix));
303         }
304 }
305
306 int main(int argc, const char **argv, char **envp)
307 {
308         const char *cmd = argv[0] ? argv[0] : "git-help";
309         char *slash = strrchr(cmd, '/');
310         const char *exec_path = NULL;
311         int done_alias = 0;
312
313         /*
314          * Take the basename of argv[0] as the command
315          * name, and the dirname as the default exec_path
316          * if it's an absolute path and we don't have
317          * anything better.
318          */
319         if (slash) {
320                 *slash++ = 0;
321                 if (*cmd == '/')
322                         exec_path = cmd;
323                 cmd = slash;
324         }
325
326         /*
327          * "git-xxxx" is the same as "git xxxx", but we obviously:
328          *
329          *  - cannot take flags in between the "git" and the "xxxx".
330          *  - cannot execute it externally (since it would just do
331          *    the same thing over again)
332          *
333          * So we just directly call the internal command handler, and
334          * die if that one cannot handle it.
335          */
336         if (!strncmp(cmd, "git-", 4)) {
337                 cmd += 4;
338                 argv[0] = cmd;
339                 handle_internal_command(argc, argv, envp);
340                 die("cannot handle %s internally", cmd);
341         }
342
343         /* Look for flags.. */
344         argv++;
345         argc--;
346         handle_options(&argv, &argc);
347         if (argc > 0) {
348                 if (!strncmp(argv[0], "--", 2))
349                         argv[0] += 2;
350         } else {
351                 /* Default command: "help" */
352                 argv[0] = "help";
353                 argc = 1;
354         }
355         cmd = argv[0];
356
357         /*
358          * We search for git commands in the following order:
359          *  - git_exec_path()
360          *  - the path of the "git" command if we could find it
361          *    in $0
362          *  - the regular PATH.
363          */
364         if (exec_path)
365                 prepend_to_path(exec_path, strlen(exec_path));
366         exec_path = git_exec_path();
367         prepend_to_path(exec_path, strlen(exec_path));
368
369         while (1) {
370                 /* See if it's an internal command */
371                 handle_internal_command(argc, argv, envp);
372
373                 /* .. then try the external ones */
374                 execv_git_cmd(argv);
375
376                 /* It could be an alias -- this works around the insanity
377                  * of overriding "git log" with "git show" by having
378                  * alias.log = show
379                  */
380                 if (done_alias || !handle_alias(&argc, &argv))
381                         break;
382                 done_alias = 1;
383         }
384
385         if (errno == ENOENT)
386                 help_unknown_cmd(cmd);
387
388         fprintf(stderr, "Failed to run command '%s': %s\n",
389                 cmd, strerror(errno));
390
391         return 1;
392 }