Builtin git-read-tree.
[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         };
61         int i;
62
63         /* Turn "git cmd --help" into "git help cmd" */
64         if (argc > 1 && !strcmp(argv[1], "--help")) {
65                 argv[1] = argv[0];
66                 argv[0] = cmd = "help";
67         }
68
69         for (i = 0; i < ARRAY_SIZE(commands); i++) {
70                 struct cmd_struct *p = commands+i;
71                 if (strcmp(p->cmd, cmd))
72                         continue;
73                 exit(p->fn(argc, argv, envp));
74         }
75 }
76
77 int main(int argc, const char **argv, char **envp)
78 {
79         const char *cmd = argv[0];
80         char *slash = strrchr(cmd, '/');
81         char git_command[PATH_MAX + 1];
82         const char *exec_path = NULL;
83
84         /*
85          * Take the basename of argv[0] as the command
86          * name, and the dirname as the default exec_path
87          * if it's an absolute path and we don't have
88          * anything better.
89          */
90         if (slash) {
91                 *slash++ = 0;
92                 if (*cmd == '/')
93                         exec_path = cmd;
94                 cmd = slash;
95         }
96
97         /*
98          * "git-xxxx" is the same as "git xxxx", but we obviously:
99          *
100          *  - cannot take flags in between the "git" and the "xxxx".
101          *  - cannot execute it externally (since it would just do
102          *    the same thing over again)
103          *
104          * So we just directly call the internal command handler, and
105          * die if that one cannot handle it.
106          */
107         if (!strncmp(cmd, "git-", 4)) {
108                 cmd += 4;
109                 argv[0] = cmd;
110                 handle_internal_command(argc, argv, envp);
111                 die("cannot handle %s internally", cmd);
112         }
113
114         /* Default command: "help" */
115         cmd = "help";
116
117         /* Look for flags.. */
118         while (argc > 1) {
119                 cmd = *++argv;
120                 argc--;
121
122                 if (strncmp(cmd, "--", 2))
123                         break;
124
125                 cmd += 2;
126
127                 /*
128                  * For legacy reasons, the "version" and "help"
129                  * commands can be written with "--" prepended
130                  * to make them look like flags.
131                  */
132                 if (!strcmp(cmd, "help"))
133                         break;
134                 if (!strcmp(cmd, "version"))
135                         break;
136
137                 /*
138                  * Check remaining flags (which by now must be
139                  * "--exec-path", but maybe we will accept
140                  * other arguments some day)
141                  */
142                 if (!strncmp(cmd, "exec-path", 9)) {
143                         cmd += 9;
144                         if (*cmd == '=') {
145                                 git_set_exec_path(cmd + 1);
146                                 continue;
147                         }
148                         puts(git_exec_path());
149                         exit(0);
150                 }
151                 cmd_usage(0, NULL, NULL);
152         }
153         argv[0] = cmd;
154
155         /*
156          * We search for git commands in the following order:
157          *  - git_exec_path()
158          *  - the path of the "git" command if we could find it
159          *    in $0
160          *  - the regular PATH.
161          */
162         if (exec_path)
163                 prepend_to_path(exec_path, strlen(exec_path));
164         exec_path = git_exec_path();
165         prepend_to_path(exec_path, strlen(exec_path));
166
167         /* See if it's an internal command */
168         handle_internal_command(argc, argv, envp);
169
170         /* .. then try the external ones */
171         execv_git_cmd(argv);
172
173         if (errno == ENOENT)
174                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
175
176         fprintf(stderr, "Failed to run command '%s': %s\n",
177                 git_command, strerror(errno));
178
179         return 1;
180 }