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