builtin-grep: do not use setup_revisions()
[git.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                 { "grep", cmd_grep },
50         };
51         int i;
52
53         /* Turn "git cmd --help" into "git help cmd" */
54         if (argc > 1 && !strcmp(argv[1], "--help")) {
55                 argv[1] = argv[0];
56                 argv[0] = cmd = "help";
57         }
58
59         for (i = 0; i < ARRAY_SIZE(commands); i++) {
60                 struct cmd_struct *p = commands+i;
61                 if (strcmp(p->cmd, cmd))
62                         continue;
63                 exit(p->fn(argc, argv, envp));
64         }
65 }
66
67 int main(int argc, const char **argv, char **envp)
68 {
69         const char *cmd = argv[0];
70         char *slash = strrchr(cmd, '/');
71         char git_command[PATH_MAX + 1];
72         const char *exec_path = NULL;
73
74         /*
75          * Take the basename of argv[0] as the command
76          * name, and the dirname as the default exec_path
77          * if it's an absolute path and we don't have
78          * anything better.
79          */
80         if (slash) {
81                 *slash++ = 0;
82                 if (*cmd == '/')
83                         exec_path = cmd;
84                 cmd = slash;
85         }
86
87         /*
88          * "git-xxxx" is the same as "git xxxx", but we obviously:
89          *
90          *  - cannot take flags in between the "git" and the "xxxx".
91          *  - cannot execute it externally (since it would just do
92          *    the same thing over again)
93          *
94          * So we just directly call the internal command handler, and
95          * die if that one cannot handle it.
96          */
97         if (!strncmp(cmd, "git-", 4)) {
98                 cmd += 4;
99                 argv[0] = cmd;
100                 handle_internal_command(argc, argv, envp);
101                 die("cannot handle %s internally", cmd);
102         }
103
104         /* Default command: "help" */
105         cmd = "help";
106
107         /* Look for flags.. */
108         while (argc > 1) {
109                 cmd = *++argv;
110                 argc--;
111
112                 if (strncmp(cmd, "--", 2))
113                         break;
114
115                 cmd += 2;
116
117                 /*
118                  * For legacy reasons, the "version" and "help"
119                  * commands can be written with "--" prepended
120                  * to make them look like flags.
121                  */
122                 if (!strcmp(cmd, "help"))
123                         break;
124                 if (!strcmp(cmd, "version"))
125                         break;
126
127                 /*
128                  * Check remaining flags (which by now must be
129                  * "--exec-path", but maybe we will accept
130                  * other arguments some day)
131                  */
132                 if (!strncmp(cmd, "exec-path", 9)) {
133                         cmd += 9;
134                         if (*cmd == '=') {
135                                 git_set_exec_path(cmd + 1);
136                                 continue;
137                         }
138                         puts(git_exec_path());
139                         exit(0);
140                 }
141                 cmd_usage(0, NULL, NULL);
142         }
143         argv[0] = cmd;
144
145         /*
146          * We search for git commands in the following order:
147          *  - git_exec_path()
148          *  - the path of the "git" command if we could find it
149          *    in $0
150          *  - the regular PATH.
151          */
152         if (exec_path)
153                 prepend_to_path(exec_path, strlen(exec_path));
154         exec_path = git_exec_path();
155         prepend_to_path(exec_path, strlen(exec_path));
156
157         /* See if it's an internal command */
158         handle_internal_command(argc, argv, envp);
159
160         /* .. then try the external ones */
161         execv_git_cmd(argv);
162
163         if (errno == ENOENT)
164                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
165
166         fprintf(stderr, "Failed to run command '%s': %s\n",
167                 git_command, strerror(errno));
168
169         return 1;
170 }