Merge branch 'jc/fmt-patch'
[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                 { "format-patch", cmd_format_patch },
51                 { "count-objects", cmd_count_objects },
52                 { "diff", cmd_diff },
53                 { "grep", cmd_grep },
54                 { "rm", cmd_rm },
55                 { "add", cmd_add },
56                 { "rev-list", cmd_rev_list },
57                 { "init-db", cmd_init_db },
58                 { "tar-tree", cmd_tar_tree },
59                 { "upload-tar", cmd_upload_tar },
60                 { "check-ref-format", cmd_check_ref_format },
61                 { "ls-files", cmd_ls_files },
62                 { "ls-tree", cmd_ls_tree },
63                 { "tar-tree", cmd_tar_tree },
64                 { "read-tree", cmd_read_tree },
65                 { "commit-tree", cmd_commit_tree },
66                 { "apply", cmd_apply },
67                 { "show-branch", cmd_show_branch },
68                 { "diff-files", cmd_diff_files },
69                 { "diff-index", cmd_diff_index },
70                 { "diff-stages", cmd_diff_stages },
71                 { "diff-tree", cmd_diff_tree },
72                 { "cat-file", cmd_cat_file },
73                 { "rev-parse", cmd_rev_parse }
74         };
75         int i;
76
77         /* Turn "git cmd --help" into "git help cmd" */
78         if (argc > 1 && !strcmp(argv[1], "--help")) {
79                 argv[1] = argv[0];
80                 argv[0] = cmd = "help";
81         }
82
83         for (i = 0; i < ARRAY_SIZE(commands); i++) {
84                 struct cmd_struct *p = commands+i;
85                 if (strcmp(p->cmd, cmd))
86                         continue;
87                 exit(p->fn(argc, argv, envp));
88         }
89 }
90
91 int main(int argc, const char **argv, char **envp)
92 {
93         const char *cmd = argv[0];
94         char *slash = strrchr(cmd, '/');
95         char git_command[PATH_MAX + 1];
96         const char *exec_path = NULL;
97
98         /*
99          * Take the basename of argv[0] as the command
100          * name, and the dirname as the default exec_path
101          * if it's an absolute path and we don't have
102          * anything better.
103          */
104         if (slash) {
105                 *slash++ = 0;
106                 if (*cmd == '/')
107                         exec_path = cmd;
108                 cmd = slash;
109         }
110
111         /*
112          * "git-xxxx" is the same as "git xxxx", but we obviously:
113          *
114          *  - cannot take flags in between the "git" and the "xxxx".
115          *  - cannot execute it externally (since it would just do
116          *    the same thing over again)
117          *
118          * So we just directly call the internal command handler, and
119          * die if that one cannot handle it.
120          */
121         if (!strncmp(cmd, "git-", 4)) {
122                 cmd += 4;
123                 argv[0] = cmd;
124                 handle_internal_command(argc, argv, envp);
125                 die("cannot handle %s internally", cmd);
126         }
127
128         /* Default command: "help" */
129         cmd = "help";
130
131         /* Look for flags.. */
132         while (argc > 1) {
133                 cmd = *++argv;
134                 argc--;
135
136                 if (strncmp(cmd, "--", 2))
137                         break;
138
139                 cmd += 2;
140
141                 /*
142                  * For legacy reasons, the "version" and "help"
143                  * commands can be written with "--" prepended
144                  * to make them look like flags.
145                  */
146                 if (!strcmp(cmd, "help"))
147                         break;
148                 if (!strcmp(cmd, "version"))
149                         break;
150
151                 /*
152                  * Check remaining flags (which by now must be
153                  * "--exec-path", but maybe we will accept
154                  * other arguments some day)
155                  */
156                 if (!strncmp(cmd, "exec-path", 9)) {
157                         cmd += 9;
158                         if (*cmd == '=') {
159                                 git_set_exec_path(cmd + 1);
160                                 continue;
161                         }
162                         puts(git_exec_path());
163                         exit(0);
164                 }
165                 cmd_usage(0, NULL, NULL);
166         }
167         argv[0] = cmd;
168
169         /*
170          * We search for git commands in the following order:
171          *  - git_exec_path()
172          *  - the path of the "git" command if we could find it
173          *    in $0
174          *  - the regular PATH.
175          */
176         if (exec_path)
177                 prepend_to_path(exec_path, strlen(exec_path));
178         exec_path = git_exec_path();
179         prepend_to_path(exec_path, strlen(exec_path));
180
181         /* See if it's an internal command */
182         handle_internal_command(argc, argv, envp);
183
184         /* .. then try the external ones */
185         execv_git_cmd(argv);
186
187         if (errno == ENOENT)
188                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
189
190         fprintf(stderr, "Failed to run command '%s': %s\n",
191                 git_command, strerror(errno));
192
193         return 1;
194 }