argv created by handle_alias should be NULL terminated
[git/git.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 static void prepend_to_path(const char *dir, int len)
19 {
20 const char *old_path = getenv("PATH");
21 char *path;
22 int path_len = len;
23
24 if (!old_path)
25 old_path = "/usr/local/bin:/usr/bin:/bin";
26
27 path_len = len + strlen(old_path) + 1;
28
29 path = malloc(path_len + 1);
30
31 memcpy(path, dir, len);
32 path[len] = ':';
33 memcpy(path + len + 1, old_path, path_len - len);
34
35 setenv("PATH", path, 1);
36 }
37
38 static const char *alias_command;
39 static char *alias_string = NULL;
40
41 static int git_alias_config(const char *var, const char *value)
42 {
43 if (!strncmp(var, "alias.", 6) && !strcmp(var + 6, alias_command)) {
44 alias_string = strdup(value);
45 }
46 return 0;
47 }
48
49 static int split_cmdline(char *cmdline, const char ***argv)
50 {
51 int src, dst, count = 0, size = 16;
52 char quoted = 0;
53
54 *argv = malloc(sizeof(char*) * size);
55
56 /* split alias_string */
57 (*argv)[count++] = cmdline;
58 for (src = dst = 0; cmdline[src];) {
59 char c = cmdline[src];
60 if (!quoted && isspace(c)) {
61 cmdline[dst++] = 0;
62 while (cmdline[++src]
63 && isspace(cmdline[src]))
64 ; /* skip */
65 if (count >= size) {
66 size += 16;
67 *argv = realloc(*argv, sizeof(char*) * size);
68 }
69 (*argv)[count++] = cmdline + dst;
70 } else if(!quoted && (c == '\'' || c == '"')) {
71 quoted = c;
72 src++;
73 } else if (c == quoted) {
74 quoted = 0;
75 src++;
76 } else {
77 if (c == '\\' && quoted != '\'') {
78 src++;
79 c = cmdline[src];
80 if (!c) {
81 free(*argv);
82 *argv = NULL;
83 return error("cmdline ends with \\");
84 }
85 }
86 cmdline[dst++] = c;
87 src++;
88 }
89 }
90
91 cmdline[dst] = 0;
92
93 if (quoted) {
94 free(*argv);
95 *argv = NULL;
96 return error("unclosed quote");
97 }
98
99 return count;
100 }
101
102 static int handle_alias(int *argcp, const char ***argv)
103 {
104 int nongit = 0, ret = 0, saved_errno = errno;
105 const char *subdir;
106
107 subdir = setup_git_directory_gently(&nongit);
108 if (!nongit) {
109 int count;
110 const char** new_argv;
111
112 alias_command = (*argv)[0];
113 git_config(git_alias_config);
114 if (alias_string) {
115
116 count = split_cmdline(alias_string, &new_argv);
117
118 if (count < 1)
119 die("empty alias for %s", alias_command);
120
121 if (!strcmp(alias_command, new_argv[0]))
122 die("recursive alias: %s", alias_command);
123
124 if (getenv("GIT_TRACE")) {
125 int i;
126 fprintf(stderr, "trace: alias expansion: %s =>",
127 alias_command);
128 for (i = 0; i < count; ++i) {
129 fputc(' ', stderr);
130 sq_quote_print(stderr, new_argv[i]);
131 }
132 fputc('\n', stderr);
133 fflush(stderr);
134 }
135
136 new_argv = realloc(new_argv, sizeof(char*) *
137 (count + *argcp + 1));
138 /* insert after command name */
139 memcpy(new_argv + count, *argv + 1,
140 sizeof(char*) * *argcp);
141 new_argv[count+*argcp] = NULL;
142
143 *argv = new_argv;
144 *argcp += count - 1;
145
146 ret = 1;
147 }
148 }
149
150 if (subdir)
151 chdir(subdir);
152
153 errno = saved_errno;
154
155 return ret;
156 }
157
158 const char git_version_string[] = GIT_VERSION;
159
160 static void handle_internal_command(int argc, const char **argv, char **envp)
161 {
162 const char *cmd = argv[0];
163 static struct cmd_struct {
164 const char *cmd;
165 int (*fn)(int, const char **, char **);
166 } commands[] = {
167 { "version", cmd_version },
168 { "help", cmd_help },
169 { "log", cmd_log },
170 { "whatchanged", cmd_whatchanged },
171 { "show", cmd_show },
172 { "push", cmd_push },
173 { "format-patch", cmd_format_patch },
174 { "count-objects", cmd_count_objects },
175 { "diff", cmd_diff },
176 { "grep", cmd_grep },
177 { "rm", cmd_rm },
178 { "add", cmd_add },
179 { "rev-list", cmd_rev_list },
180 { "init-db", cmd_init_db },
181 { "get-tar-commit-id", cmd_get_tar_commit_id },
182 { "upload-tar", cmd_upload_tar },
183 { "check-ref-format", cmd_check_ref_format },
184 { "ls-files", cmd_ls_files },
185 { "ls-tree", cmd_ls_tree },
186 { "tar-tree", cmd_tar_tree },
187 { "read-tree", cmd_read_tree },
188 { "commit-tree", cmd_commit_tree },
189 { "apply", cmd_apply },
190 { "show-branch", cmd_show_branch },
191 { "diff-files", cmd_diff_files },
192 { "diff-index", cmd_diff_index },
193 { "diff-stages", cmd_diff_stages },
194 { "diff-tree", cmd_diff_tree },
195 { "cat-file", cmd_cat_file },
196 { "rev-parse", cmd_rev_parse },
197 { "write-tree", cmd_write_tree },
198 { "mailsplit", cmd_mailsplit },
199 { "mailinfo", cmd_mailinfo },
200 { "stripspace", cmd_stripspace },
201 { "update-index", cmd_update_index },
202 { "update-ref", cmd_update_ref },
203 { "fmt-merge-msg", cmd_fmt_merge_msg },
204 { "prune", cmd_prune },
205 };
206 int i;
207
208 /* Turn "git cmd --help" into "git help cmd" */
209 if (argc > 1 && !strcmp(argv[1], "--help")) {
210 argv[1] = argv[0];
211 argv[0] = cmd = "help";
212 }
213
214 for (i = 0; i < ARRAY_SIZE(commands); i++) {
215 struct cmd_struct *p = commands+i;
216 if (strcmp(p->cmd, cmd))
217 continue;
218
219 if (getenv("GIT_TRACE")) {
220 int i;
221 fprintf(stderr, "trace: built-in: git");
222 for (i = 0; i < argc; ++i) {
223 fputc(' ', stderr);
224 sq_quote_print(stderr, argv[i]);
225 }
226 putc('\n', stderr);
227 fflush(stderr);
228 }
229
230 exit(p->fn(argc, argv, envp));
231 }
232 }
233
234 int main(int argc, const char **argv, char **envp)
235 {
236 const char *cmd = argv[0];
237 char *slash = strrchr(cmd, '/');
238 const char *exec_path = NULL;
239 int done_alias = 0;
240
241 /*
242 * Take the basename of argv[0] as the command
243 * name, and the dirname as the default exec_path
244 * if it's an absolute path and we don't have
245 * anything better.
246 */
247 if (slash) {
248 *slash++ = 0;
249 if (*cmd == '/')
250 exec_path = cmd;
251 cmd = slash;
252 }
253
254 /*
255 * "git-xxxx" is the same as "git xxxx", but we obviously:
256 *
257 * - cannot take flags in between the "git" and the "xxxx".
258 * - cannot execute it externally (since it would just do
259 * the same thing over again)
260 *
261 * So we just directly call the internal command handler, and
262 * die if that one cannot handle it.
263 */
264 if (!strncmp(cmd, "git-", 4)) {
265 cmd += 4;
266 argv[0] = cmd;
267 handle_internal_command(argc, argv, envp);
268 die("cannot handle %s internally", cmd);
269 }
270
271 /* Default command: "help" */
272 cmd = "help";
273
274 /* Look for flags.. */
275 while (argc > 1) {
276 cmd = *++argv;
277 argc--;
278
279 if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
280 setup_pager();
281 continue;
282 }
283
284 if (strncmp(cmd, "--", 2))
285 break;
286
287 cmd += 2;
288
289 /*
290 * For legacy reasons, the "version" and "help"
291 * commands can be written with "--" prepended
292 * to make them look like flags.
293 */
294 if (!strcmp(cmd, "help"))
295 break;
296 if (!strcmp(cmd, "version"))
297 break;
298
299 /*
300 * Check remaining flags (which by now must be
301 * "--exec-path", but maybe we will accept
302 * other arguments some day)
303 */
304 if (!strncmp(cmd, "exec-path", 9)) {
305 cmd += 9;
306 if (*cmd == '=') {
307 git_set_exec_path(cmd + 1);
308 continue;
309 }
310 puts(git_exec_path());
311 exit(0);
312 }
313 cmd_usage(0, NULL, NULL);
314 }
315 argv[0] = cmd;
316
317 /*
318 * We search for git commands in the following order:
319 * - git_exec_path()
320 * - the path of the "git" command if we could find it
321 * in $0
322 * - the regular PATH.
323 */
324 if (exec_path)
325 prepend_to_path(exec_path, strlen(exec_path));
326 exec_path = git_exec_path();
327 prepend_to_path(exec_path, strlen(exec_path));
328
329 while (1) {
330 /* See if it's an internal command */
331 handle_internal_command(argc, argv, envp);
332
333 /* .. then try the external ones */
334 execv_git_cmd(argv);
335
336 /* It could be an alias -- this works around the insanity
337 * of overriding "git log" with "git show" by having
338 * alias.log = show
339 */
340 if (done_alias || !handle_alias(&argc, &argv))
341 break;
342 done_alias = 1;
343 }
344
345 if (errno == ENOENT)
346 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
347
348 fprintf(stderr, "Failed to run command '%s': %s\n",
349 cmd, strerror(errno));
350
351 return 1;
352 }