Andrew's git - gitweb.git/blob

   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
  16static 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
  35const char git_version_string[] = GIT_VERSION;
  36
  37static 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        };
  50        int i;
  51
  52        /* Turn "git cmd --help" into "git help cmd" */
  53        if (argc > 1 && !strcmp(argv[1], "--help")) {
  54                argv[1] = argv[0];
  55                argv[0] = cmd = "help";
  56        }
  57
  58        for (i = 0; i < ARRAY_SIZE(commands); i++) {
  59                struct cmd_struct *p = commands+i;
  60                if (strcmp(p->cmd, cmd))
  61                        continue;
  62                exit(p->fn(argc, argv, envp));
  63        }
  64}
  65
  66int main(int argc, const char **argv, char **envp)
  67{
  68        const char *cmd = argv[0];
  69        char *slash = strrchr(cmd, '/');
  70        char git_command[PATH_MAX + 1];
  71        const char *exec_path = NULL;
  72
  73        /*
  74         * Take the basename of argv[0] as the command
  75         * name, and the dirname as the default exec_path
  76         * if it's an absolute path and we don't have
  77         * anything better.
  78         */
  79        if (slash) {
  80                *slash++ = 0;
  81                if (*cmd == '/')
  82                        exec_path = cmd;
  83                cmd = slash;
  84        }
  85
  86        /*
  87         * "git-xxxx" is the same as "git xxxx", but we obviously:
  88         *
  89         *  - cannot take flags in between the "git" and the "xxxx".
  90         *  - cannot execute it externally (since it would just do
  91         *    the same thing over again)
  92         *
  93         * So we just directly call the internal command handler, and
  94         * die if that one cannot handle it.
  95         */
  96        if (!strncmp(cmd, "git-", 4)) {
  97                cmd += 4;
  98                argv[0] = cmd;
  99                handle_internal_command(argc, argv, envp);
 100                die("cannot handle %s internally", cmd);
 101        }
 102
 103        /* Default command: "help" */
 104        cmd = "help";
 105
 106        /* Look for flags.. */
 107        while (argc > 1) {
 108                cmd = *++argv;
 109                argc--;
 110
 111                if (strncmp(cmd, "--", 2))
 112                        break;
 113
 114                cmd += 2;
 115
 116                /*
 117                 * For legacy reasons, the "version" and "help"
 118                 * commands can be written with "--" prepended
 119                 * to make them look like flags.
 120                 */
 121                if (!strcmp(cmd, "help"))
 122                        break;
 123                if (!strcmp(cmd, "version"))
 124                        break;
 125
 126                /*
 127                 * Check remaining flags (which by now must be
 128                 * "--exec-path", but maybe we will accept
 129                 * other arguments some day)
 130                 */
 131                if (!strncmp(cmd, "exec-path", 9)) {
 132                        cmd += 9;
 133                        if (*cmd == '=') {
 134                                git_set_exec_path(cmd + 1);
 135                                continue;
 136                        }
 137                        puts(git_exec_path());
 138                        exit(0);
 139                }
 140                cmd_usage(0, NULL, NULL);
 141        }
 142        argv[0] = cmd;
 143
 144        /*
 145         * We search for git commands in the following order:
 146         *  - git_exec_path()
 147         *  - the path of the "git" command if we could find it
 148         *    in $0
 149         *  - the regular PATH.
 150         */
 151        if (exec_path)
 152                prepend_to_path(exec_path, strlen(exec_path));
 153        exec_path = git_exec_path();
 154        prepend_to_path(exec_path, strlen(exec_path));
 155
 156        /* See if it's an internal command */
 157        handle_internal_command(argc, argv, envp);
 158
 159        /* .. then try the external ones */
 160        execv_git_cmd(argv);
 161
 162        if (errno == ENOENT)
 163                cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
 164
 165        fprintf(stderr, "Failed to run command '%s': %s\n",
 166                git_command, strerror(errno));
 167
 168        return 1;
 169}