Builtin git-init-db
[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         };
57         int i;
58
59         /* Turn "git cmd --help" into "git help cmd" */
60         if (argc > 1 && !strcmp(argv[1], "--help")) {
61                 argv[1] = argv[0];
62                 argv[0] = cmd = "help";
63         }
64
65         for (i = 0; i < ARRAY_SIZE(commands); i++) {
66                 struct cmd_struct *p = commands+i;
67                 if (strcmp(p->cmd, cmd))
68                         continue;
69                 exit(p->fn(argc, argv, envp));
70         }
71 }
72
73 int main(int argc, const char **argv, char **envp)
74 {
75         const char *cmd = argv[0];
76         char *slash = strrchr(cmd, '/');
77         char git_command[PATH_MAX + 1];
78         const char *exec_path = NULL;
79
80         /*
81          * Take the basename of argv[0] as the command
82          * name, and the dirname as the default exec_path
83          * if it's an absolute path and we don't have
84          * anything better.
85          */
86         if (slash) {
87                 *slash++ = 0;
88                 if (*cmd == '/')
89                         exec_path = cmd;
90                 cmd = slash;
91         }
92
93         /*
94          * "git-xxxx" is the same as "git xxxx", but we obviously:
95          *
96          *  - cannot take flags in between the "git" and the "xxxx".
97          *  - cannot execute it externally (since it would just do
98          *    the same thing over again)
99          *
100          * So we just directly call the internal command handler, and
101          * die if that one cannot handle it.
102          */
103         if (!strncmp(cmd, "git-", 4)) {
104                 cmd += 4;
105                 argv[0] = cmd;
106                 handle_internal_command(argc, argv, envp);
107                 die("cannot handle %s internally", cmd);
108         }
109
110         /* Default command: "help" */
111         cmd = "help";
112
113         /* Look for flags.. */
114         while (argc > 1) {
115                 cmd = *++argv;
116                 argc--;
117
118                 if (strncmp(cmd, "--", 2))
119                         break;
120
121                 cmd += 2;
122
123                 /*
124                  * For legacy reasons, the "version" and "help"
125                  * commands can be written with "--" prepended
126                  * to make them look like flags.
127                  */
128                 if (!strcmp(cmd, "help"))
129                         break;
130                 if (!strcmp(cmd, "version"))
131                         break;
132
133                 /*
134                  * Check remaining flags (which by now must be
135                  * "--exec-path", but maybe we will accept
136                  * other arguments some day)
137                  */
138                 if (!strncmp(cmd, "exec-path", 9)) {
139                         cmd += 9;
140                         if (*cmd == '=') {
141                                 git_set_exec_path(cmd + 1);
142                                 continue;
143                         }
144                         puts(git_exec_path());
145                         exit(0);
146                 }
147                 cmd_usage(0, NULL, NULL);
148         }
149         argv[0] = cmd;
150
151         /*
152          * We search for git commands in the following order:
153          *  - git_exec_path()
154          *  - the path of the "git" command if we could find it
155          *    in $0
156          *  - the regular PATH.
157          */
158         if (exec_path)
159                 prepend_to_path(exec_path, strlen(exec_path));
160         exec_path = git_exec_path();
161         prepend_to_path(exec_path, strlen(exec_path));
162
163         /* See if it's an internal command */
164         handle_internal_command(argc, argv, envp);
165
166         /* .. then try the external ones */
167         execv_git_cmd(argv);
168
169         if (errno == ENOENT)
170                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
171
172         fprintf(stderr, "Failed to run command '%s': %s\n",
173                 git_command, strerror(errno));
174
175         return 1;
176 }