Merge branch 'maint'
[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         };
54         int i;
55
56         /* Turn "git cmd --help" into "git help cmd" */
57         if (argc > 1 && !strcmp(argv[1], "--help")) {
58                 argv[1] = argv[0];
59                 argv[0] = cmd = "help";
60         }
61
62         for (i = 0; i < ARRAY_SIZE(commands); i++) {
63                 struct cmd_struct *p = commands+i;
64                 if (strcmp(p->cmd, cmd))
65                         continue;
66                 exit(p->fn(argc, argv, envp));
67         }
68 }
69
70 int main(int argc, const char **argv, char **envp)
71 {
72         const char *cmd = argv[0];
73         char *slash = strrchr(cmd, '/');
74         char git_command[PATH_MAX + 1];
75         const char *exec_path = NULL;
76
77         /*
78          * Take the basename of argv[0] as the command
79          * name, and the dirname as the default exec_path
80          * if it's an absolute path and we don't have
81          * anything better.
82          */
83         if (slash) {
84                 *slash++ = 0;
85                 if (*cmd == '/')
86                         exec_path = cmd;
87                 cmd = slash;
88         }
89
90         /*
91          * "git-xxxx" is the same as "git xxxx", but we obviously:
92          *
93          *  - cannot take flags in between the "git" and the "xxxx".
94          *  - cannot execute it externally (since it would just do
95          *    the same thing over again)
96          *
97          * So we just directly call the internal command handler, and
98          * die if that one cannot handle it.
99          */
100         if (!strncmp(cmd, "git-", 4)) {
101                 cmd += 4;
102                 argv[0] = cmd;
103                 handle_internal_command(argc, argv, envp);
104                 die("cannot handle %s internally", cmd);
105         }
106
107         /* Default command: "help" */
108         cmd = "help";
109
110         /* Look for flags.. */
111         while (argc > 1) {
112                 cmd = *++argv;
113                 argc--;
114
115                 if (strncmp(cmd, "--", 2))
116                         break;
117
118                 cmd += 2;
119
120                 /*
121                  * For legacy reasons, the "version" and "help"
122                  * commands can be written with "--" prepended
123                  * to make them look like flags.
124                  */
125                 if (!strcmp(cmd, "help"))
126                         break;
127                 if (!strcmp(cmd, "version"))
128                         break;
129
130                 /*
131                  * Check remaining flags (which by now must be
132                  * "--exec-path", but maybe we will accept
133                  * other arguments some day)
134                  */
135                 if (!strncmp(cmd, "exec-path", 9)) {
136                         cmd += 9;
137                         if (*cmd == '=') {
138                                 git_set_exec_path(cmd + 1);
139                                 continue;
140                         }
141                         puts(git_exec_path());
142                         exit(0);
143                 }
144                 cmd_usage(0, NULL, NULL);
145         }
146         argv[0] = cmd;
147
148         /*
149          * We search for git commands in the following order:
150          *  - git_exec_path()
151          *  - the path of the "git" command if we could find it
152          *    in $0
153          *  - the regular PATH.
154          */
155         if (exec_path)
156                 prepend_to_path(exec_path, strlen(exec_path));
157         exec_path = git_exec_path();
158         prepend_to_path(exec_path, strlen(exec_path));
159
160         /* See if it's an internal command */
161         handle_internal_command(argc, argv, envp);
162
163         /* .. then try the external ones */
164         execv_git_cmd(argv);
165
166         if (errno == ENOENT)
167                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
168
169         fprintf(stderr, "Failed to run command '%s': %s\n",
170                 git_command, strerror(errno));
171
172         return 1;
173 }