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