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                { "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
  70int 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}