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         };
50         int i;
51
52         /* Turn "git cmd --help" into "git help cmd" */
53         if (argc > 1 && !strcmp(argv[1], "--help")) {
54                 argv[1] = argv[0];
55                 argv[0] = cmd = "help";
56         }
57
58         for (i = 0; i < ARRAY_SIZE(commands); i++) {
59                 struct cmd_struct *p = commands+i;
60                 if (strcmp(p->cmd, cmd))
61                         continue;
62                 exit(p->fn(argc, argv, envp));
63         }
64 }
65
66 int main(int argc, const char **argv, char **envp)
67 {
68         const char *cmd = argv[0];
69         char *slash = strrchr(cmd, '/');
70         char git_command[PATH_MAX + 1];
71         const char *exec_path = NULL;
72
73         /*
74          * Take the basename of argv[0] as the command
75          * name, and the dirname as the default exec_path
76          * if it's an absolute path and we don't have
77          * anything better.
78          */
79         if (slash) {
80                 *slash++ = 0;
81                 if (*cmd == '/')
82                         exec_path = cmd;
83                 cmd = slash;
84         }
85
86         /*
87          * "git-xxxx" is the same as "git xxxx", but we obviously:
88          *
89          *  - cannot take flags in between the "git" and the "xxxx".
90          *  - cannot execute it externally (since it would just do
91          *    the same thing over again)
92          *
93          * So we just directly call the internal command handler, and
94          * die if that one cannot handle it.
95          */
96         if (!strncmp(cmd, "git-", 4)) {
97                 cmd += 4;
98                 argv[0] = cmd;
99                 handle_internal_command(argc, argv, envp);
100                 die("cannot handle %s internally", cmd);
101         }
102
103         /* Default command: "help" */
104         cmd = "help";
105
106         /* Look for flags.. */
107         while (argc > 1) {
108                 cmd = *++argv;
109                 argc--;
110
111                 if (strncmp(cmd, "--", 2))
112                         break;
113
114                 cmd += 2;
115
116                 /*
117                  * For legacy reasons, the "version" and "help"
118                  * commands can be written with "--" prepended
119                  * to make them look like flags.
120                  */
121                 if (!strcmp(cmd, "help"))
122                         break;
123                 if (!strcmp(cmd, "version"))
124                         break;
125
126                 /*
127                  * Check remaining flags (which by now must be
128                  * "--exec-path", but maybe we will accept
129                  * other arguments some day)
130                  */
131                 if (!strncmp(cmd, "exec-path", 9)) {
132                         cmd += 9;
133                         if (*cmd == '=') {
134                                 git_set_exec_path(cmd + 1);
135                                 continue;
136                         }
137                         puts(git_exec_path());
138                         exit(0);
139                 }
140                 cmd_usage(0, NULL, NULL);
141         }
142         argv[0] = cmd;
143
144         /*
145          * We search for git commands in the following order:
146          *  - git_exec_path()
147          *  - the path of the "git" command if we could find it
148          *    in $0
149          *  - the regular PATH.
150          */
151         if (exec_path)
152                 prepend_to_path(exec_path, strlen(exec_path));
153         exec_path = git_exec_path();
154         prepend_to_path(exec_path, strlen(exec_path));
155
156         /* See if it's an internal command */
157         handle_internal_command(argc, argv, envp);
158
159         /* .. then try the external ones */
160         execv_git_cmd(argv);
161
162         if (errno == ENOENT)
163                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
164
165         fprintf(stderr, "Failed to run command '%s': %s\n",
166                 git_command, strerror(errno));
167
168         return 1;
169 }