Merge branch 'maint'
[gitweb.git] / git.c
diff --git a/git.c b/git.c
index 5e7da74b6800a4256f9bcb0d0add7560213271e1..993cd0d4904be11edb6234e47d10376733928740 100644 (file)
--- a/git.c
+++ b/git.c
@@ -10,6 +10,7 @@
 #include <stdarg.h>
 #include <sys/ioctl.h>
 #include "git-compat-util.h"
+#include "exec_cmd.h"
 
 #ifndef PATH_MAX
 # define PATH_MAX 4096
@@ -229,91 +230,141 @@ static void show_man_page(char *git_cmd)
        execlp("man", "man", page, NULL);
 }
 
-int main(int argc, char **argv, char **envp)
+static int cmd_version(int argc, char **argv, char **envp)
 {
-       char git_command[PATH_MAX + 1];
-       char wd[PATH_MAX + 1];
-       int i, len, show_help = 0;
-       char *exec_path = getenv("GIT_EXEC_PATH");
-
-       getcwd(wd, PATH_MAX);
+       printf("git version %s\n", GIT_VERSION);
+       return 0;
+}
 
-       if (!exec_path)
-               exec_path = GIT_EXEC_PATH;
+static int cmd_help(int argc, char **argv, char **envp)
+{
+       char *help_cmd = argv[1];
+       if (!help_cmd)
+               cmd_usage(git_exec_path(), NULL);
+       show_man_page(help_cmd);
+       return 0;
+}
 
-       for (i = 1; i < argc; i++) {
-               char *arg = argv[i];
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 
-               if (!strcmp(arg, "help")) {
-                       show_help = 1;
+static void handle_internal_command(int argc, char **argv, char **envp)
+{
+       const char *cmd = argv[0];
+       static struct cmd_struct {
+               const char *cmd;
+               int (*fn)(int, char **, char **);
+       } commands[] = {
+               { "version", cmd_version },
+               { "help", cmd_help },
+       };
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(commands); i++) {
+               struct cmd_struct *p = commands+i;
+               if (strcmp(p->cmd, cmd))
                        continue;
-               }
-
-               if (strncmp(arg, "--", 2))
-                       break;
+               exit(p->fn(argc, argv, envp));
+       }
+}
 
-               arg += 2;
+int main(int argc, char **argv, char **envp)
+{
+       char *cmd = argv[0];
+       char *slash = strrchr(cmd, '/');
+       char git_command[PATH_MAX + 1];
+       const char *exec_path = NULL;
+
+       /*
+        * Take the basename of argv[0] as the command
+        * name, and the dirname as the default exec_path
+        * if it's an absolute path and we don't have
+        * anything better.
+        */
+       if (slash) {
+               *slash++ = 0;
+               if (*cmd == '/')
+                       exec_path = cmd;
+               cmd = slash;
+       }
 
-               if (!strncmp(arg, "exec-path", 9)) {
-                       arg += 9;
-                       if (*arg == '=')
-                               exec_path = arg + 1;
-                       else {
-                               puts(exec_path);
-                               exit(0);
-                       }
-               }
-               else if (!strcmp(arg, "version")) {
-                       printf("git version %s\n", GIT_VERSION);
-                       exit(0);
-               }
-               else if (!strcmp(arg, "help"))
-                       show_help = 1;
-               else if (!show_help)
-                       cmd_usage(NULL, NULL);
+       /*
+        * "git-xxxx" is the same as "git xxxx", but we obviously:
+        *
+        *  - cannot take flags in between the "git" and the "xxxx".
+        *  - cannot execute it externally (since it would just do
+        *    the same thing over again)
+        *
+        * So we just directly call the internal command handler, and
+        * die if that one cannot handle it.
+        */
+       if (!strncmp(cmd, "git-", 4)) {
+               cmd += 4;
+               argv[0] = cmd;
+               handle_internal_command(argc, argv, envp);
+               die("cannot handle %s internally", cmd);
        }
 
-       if (i >= argc || show_help) {
-               if (i >= argc)
-                       cmd_usage(exec_path, NULL);
+       /* Default command: "help" */
+       cmd = "help";
 
-               show_man_page(argv[i]);
-       }
+       /* Look for flags.. */
+       while (argc > 1) {
+               cmd = *++argv;
+               argc--;
 
-       if (*exec_path != '/') {
-               if (!getcwd(git_command, sizeof(git_command))) {
-                       fprintf(stderr,
-                               "git: cannot determine current directory\n");
-                       exit(1);
-               }
-               len = strlen(git_command);
+               if (strncmp(cmd, "--", 2))
+                       break;
+
+               cmd += 2;
+
+               /*
+                * For legacy reasons, the "version" and "help"
+                * commands can be written with "--" prepended
+                * to make them look like flags.
+                */
+               if (!strcmp(cmd, "help"))
+                       break;
+               if (!strcmp(cmd, "version"))
+                       break;
 
-               /* Trivial cleanup */
-               while (!strncmp(exec_path, "./", 2)) {
-                       exec_path += 2;
-                       while (*exec_path == '/')
-                               exec_path++;
+               /*
+                * Check remaining flags (which by now must be
+                * "--exec-path", but maybe we will accept
+                * other arguments some day)
+                */
+               if (!strncmp(cmd, "exec-path", 9)) {
+                       cmd += 9;
+                       if (*cmd == '=') {
+                               git_set_exec_path(cmd + 1);
+                               continue;
+                       }
+                       puts(git_exec_path());
+                       exit(0);
                }
-               snprintf(git_command + len, sizeof(git_command) - len,
-                        "/%s", exec_path);
+               cmd_usage(NULL, NULL);
        }
-       else
-               strcpy(git_command, exec_path);
-       len = strlen(git_command);
-       prepend_to_path(git_command, len);
-
-       len += snprintf(git_command + len, sizeof(git_command) - len,
-                       "/git-%s", argv[i]);
-       if (sizeof(git_command) <= len) {
-               fprintf(stderr, "git: command name given is too long.\n");
-               exit(1);
-       }
-
-       /* execve() can only ever return if it fails */
-       execve(git_command, &argv[i], envp);
+       argv[0] = cmd;
+
+       /*
+        * We search for git commands in the following order:
+        *  - git_exec_path()
+        *  - the path of the "git" command if we could find it
+        *    in $0
+        *  - the regular PATH.
+        */
+       if (exec_path)
+               prepend_to_path(exec_path, strlen(exec_path));
+       exec_path = git_exec_path();
+       prepend_to_path(exec_path, strlen(exec_path));
+
+       /* See if it's an internal command */
+       handle_internal_command(argc, argv, envp);
+
+       /* .. then try the external ones */
+       execv_git_cmd(argv);
 
        if (errno == ENOENT)
-               cmd_usage(exec_path, "'%s' is not a git-command", argv[i]);
+               cmd_usage(exec_path, "'%s' is not a git-command", cmd);
 
        fprintf(stderr, "Failed to run command '%s': %s\n",
                git_command, strerror(errno));