Builtin git-commit-tree.
[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
14 #include "builtin.h"
15
16 static void prepend_to_path(const char *dir, int len)
17 {
18         char *path, *old_path = getenv("PATH");
19         int path_len = len;
20
21         if (!old_path)
22                 old_path = "/usr/local/bin:/usr/bin:/bin";
23
24         path_len = len + strlen(old_path) + 1;
25
26         path = malloc(path_len + 1);
27
28         memcpy(path, dir, len);
29         path[len] = ':';
30         memcpy(path + len + 1, old_path, path_len - len);
31
32         setenv("PATH", path, 1);
33 }
34
35 const char git_version_string[] = GIT_VERSION;
36
37 static void handle_internal_command(int argc, const char **argv, char **envp)
38 {
39         const char *cmd = argv[0];
40         static struct cmd_struct {
41                 const char *cmd;
42                 int (*fn)(int, const char **, char **);
43         } commands[] = {
44                 { "version", cmd_version },
45                 { "help", cmd_help },
46                 { "log", cmd_log },
47                 { "whatchanged", cmd_whatchanged },
48                 { "show", cmd_show },
49                 { "push", cmd_push },
50                 { "count-objects", cmd_count_objects },
51                 { "diff", cmd_diff },
52                 { "grep", cmd_grep },
53                 { "rev-list", cmd_rev_list },
54                 { "init-db", cmd_init_db },
55                 { "check-ref-format", cmd_check_ref_format },
56                 { "ls-files", cmd_ls_files },
57                 { "ls-tree", cmd_ls_tree },
58                 { "tar-tree", cmd_tar_tree },
59                 { "read-tree", cmd_read_tree },
60                 { "commit-tree", cmd_commit_tree }
61         };
62         int i;
63
64         /* Turn "git cmd --help" into "git help cmd" */
65         if (argc > 1 && !strcmp(argv[1], "--help")) {
66                 argv[1] = argv[0];
67                 argv[0] = cmd = "help";
68         }
69
70         for (i = 0; i < ARRAY_SIZE(commands); i++) {
71                 struct cmd_struct *p = commands+i;
72                 if (strcmp(p->cmd, cmd))
73                         continue;
74                 exit(p->fn(argc, argv, envp));
75         }
76 }
77
78 int main(int argc, const char **argv, char **envp)
79 {
80         const char *cmd = argv[0];
81         char *slash = strrchr(cmd, '/');
82         char git_command[PATH_MAX + 1];
83         const char *exec_path = NULL;
84
85         /*
86          * Take the basename of argv[0] as the command
87          * name, and the dirname as the default exec_path
88          * if it's an absolute path and we don't have
89          * anything better.
90          */
91         if (slash) {
92                 *slash++ = 0;
93                 if (*cmd == '/')
94                         exec_path = cmd;
95                 cmd = slash;
96         }
97
98         /*
99          * "git-xxxx" is the same as "git xxxx", but we obviously:
100          *
101          *  - cannot take flags in between the "git" and the "xxxx".
102          *  - cannot execute it externally (since it would just do
103          *    the same thing over again)
104          *
105          * So we just directly call the internal command handler, and
106          * die if that one cannot handle it.
107          */
108         if (!strncmp(cmd, "git-", 4)) {
109                 cmd += 4;
110                 argv[0] = cmd;
111                 handle_internal_command(argc, argv, envp);
112                 die("cannot handle %s internally", cmd);
113         }
114
115         /* Default command: "help" */
116         cmd = "help";
117
118         /* Look for flags.. */
119         while (argc > 1) {
120                 cmd = *++argv;
121                 argc--;
122
123                 if (strncmp(cmd, "--", 2))
124                         break;
125
126                 cmd += 2;
127
128                 /*
129                  * For legacy reasons, the "version" and "help"
130                  * commands can be written with "--" prepended
131                  * to make them look like flags.
132                  */
133                 if (!strcmp(cmd, "help"))
134                         break;
135                 if (!strcmp(cmd, "version"))
136                         break;
137
138                 /*
139                  * Check remaining flags (which by now must be
140                  * "--exec-path", but maybe we will accept
141                  * other arguments some day)
142                  */
143                 if (!strncmp(cmd, "exec-path", 9)) {
144                         cmd += 9;
145                         if (*cmd == '=') {
146                                 git_set_exec_path(cmd + 1);
147                                 continue;
148                         }
149                         puts(git_exec_path());
150                         exit(0);
151                 }
152                 cmd_usage(0, NULL, NULL);
153         }
154         argv[0] = cmd;
155
156         /*
157          * We search for git commands in the following order:
158          *  - git_exec_path()
159          *  - the path of the "git" command if we could find it
160          *    in $0
161          *  - the regular PATH.
162          */
163         if (exec_path)
164                 prepend_to_path(exec_path, strlen(exec_path));
165         exec_path = git_exec_path();
166         prepend_to_path(exec_path, strlen(exec_path));
167
168         /* See if it's an internal command */
169         handle_internal_command(argc, argv, envp);
170
171         /* .. then try the external ones */
172         execv_git_cmd(argv);
173
174         if (errno == ENOENT)
175                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
176
177         fprintf(stderr, "Failed to run command '%s': %s\n",
178                 git_command, strerror(errno));
179
180         return 1;
181 }