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