git.c

   1 #include "builtin.h"
   2 #include "exec_cmd.h"
   3 #include "cache.h"
   4 #include "quote.h"
   5
   6 const char git_usage_string[] =
   7         "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate] [--bare] [--git-dir=GIT_DIR] [--help] COMMAND [ARGS]";
   8
   9 static void prepend_to_path(const char *dir, int len)
  10 {
  11         const char *old_path = getenv("PATH");
  12         char *path;
  13         int path_len = len;
  14
  15         if (!old_path)
  16                 old_path = "/usr/local/bin:/usr/bin:/bin";
  17
  18         path_len = len + strlen(old_path) + 1;
  19
  20         path = xmalloc(path_len + 1);
  21
  22         memcpy(path, dir, len);
  23         path[len] = ':';
  24         memcpy(path + len + 1, old_path, path_len - len);
  25
  26         setenv("PATH", path, 1);
  27
  28         free(path);
  29 }
  30
  31 static int handle_options(const char*** argv, int* argc)
  32 {
  33         int handled = 0;
  34
  35         while (*argc > 0) {
  36                 const char *cmd = (*argv)[0];
  37                 if (cmd[0] != '-')
  38                         break;
  39
  40                 /*
  41                  * For legacy reasons, the "version" and "help"
  42                  * commands can be written with "--" prepended
  43                  * to make them look like flags.
  44                  */
  45                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  46                         break;
  47
  48                 /*
  49                  * Check remaining flags.
  50                  */
  51                 if (!strncmp(cmd, "--exec-path", 11)) {
  52                         cmd += 11;
  53                         if (*cmd == '=')
  54                                 git_set_exec_path(cmd + 1);
  55                         else {
  56                                 puts(git_exec_path());
  57                                 exit(0);
  58                         }
  59                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  60                         setup_pager();
  61                 } else if (!strcmp(cmd, "--git-dir")) {
  62                         if (*argc < 1)
  63                                 return -1;
  64                         setenv("GIT_DIR", (*argv)[1], 1);
  65                         (*argv)++;
  66                         (*argc)--;
  67                 } else if (!strncmp(cmd, "--git-dir=", 10)) {
  68                         setenv("GIT_DIR", cmd + 10, 1);
  69                 } else if (!strcmp(cmd, "--bare")) {
  70                         static char git_dir[1024];
  71                         setenv("GIT_DIR", getcwd(git_dir, 1024), 1);
  72                 } else {
  73                         fprintf(stderr, "Unknown option: %s\n", cmd);
  74                         usage(git_usage_string);
  75                 }
  76
  77                 (*argv)++;
  78                 (*argc)--;
  79                 handled++;
  80         }
  81         return handled;
  82 }
  83
  84 static const char *alias_command;
  85 static char *alias_string;
  86
  87 static int git_alias_config(const char *var, const char *value)
  88 {
  89         if (!strncmp(var, "alias.", 6) && !strcmp(var + 6, alias_command)) {
  90                 alias_string = xstrdup(value);
  91         }
  92         return 0;
  93 }
  94
  95 static int split_cmdline(char *cmdline, const char ***argv)
  96 {
  97         int src, dst, count = 0, size = 16;
  98         char quoted = 0;
  99
 100         *argv = malloc(sizeof(char*) * size);
 101
 102         /* split alias_string */
 103         (*argv)[count++] = cmdline;
 104         for (src = dst = 0; cmdline[src];) {
 105                 char c = cmdline[src];
 106                 if (!quoted && isspace(c)) {
 107                         cmdline[dst++] = 0;
 108                         while (cmdline[++src]
 109                                         && isspace(cmdline[src]))
 110                                 ; /* skip */
 111                         if (count >= size) {
 112                                 size += 16;
 113                                 *argv = xrealloc(*argv, sizeof(char*) * size);
 114                         }
 115                         (*argv)[count++] = cmdline + dst;
 116                 } else if(!quoted && (c == '\'' || c == '"')) {
 117                         quoted = c;
 118                         src++;
 119                 } else if (c == quoted) {
 120                         quoted = 0;
 121                         src++;
 122                 } else {
 123                         if (c == '\\' && quoted != '\'') {
 124                                 src++;
 125                                 c = cmdline[src];
 126                                 if (!c) {
 127                                         free(*argv);
 128                                         *argv = NULL;
 129                                         return error("cmdline ends with \\");
 130                                 }
 131                         }
 132                         cmdline[dst++] = c;
 133                         src++;
 134                 }
 135         }
 136
 137         cmdline[dst] = 0;
 138
 139         if (quoted) {
 140                 free(*argv);
 141                 *argv = NULL;
 142                 return error("unclosed quote");
 143         }
 144
 145         return count;
 146 }
 147
 148 static int handle_alias(int *argcp, const char ***argv)
 149 {
 150         int nongit = 0, ret = 0, saved_errno = errno;
 151         const char *subdir;
 152         int count, option_count;
 153         const char** new_argv;
 154
 155         subdir = setup_git_directory_gently(&nongit);
 156
 157         alias_command = (*argv)[0];
 158         git_config(git_alias_config);
 159         if (alias_string) {
 160                 count = split_cmdline(alias_string, &new_argv);
 161                 option_count = handle_options(&new_argv, &count);
 162                 memmove(new_argv - option_count, new_argv,
 163                                 count * sizeof(char *));
 164                 new_argv -= option_count;
 165
 166                 if (count < 1)
 167                         die("empty alias for %s", alias_command);
 168
 169                 if (!strcmp(alias_command, new_argv[0]))
 170                         die("recursive alias: %s", alias_command);
 171
 172                 trace_argv_printf(new_argv, count,
 173                                   "trace: alias expansion: %s =>",
 174                                   alias_command);
 175
 176                 new_argv = xrealloc(new_argv, sizeof(char*) *
 177                                     (count + *argcp + 1));
 178                 /* insert after command name */
 179                 memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
 180                 new_argv[count+*argcp] = NULL;
 181
 182                 *argv = new_argv;
 183                 *argcp += count - 1;
 184
 185                 ret = 1;
 186         }
 187
 188         if (subdir)
 189                 chdir(subdir);
 190
 191         errno = saved_errno;
 192
 193         return ret;
 194 }
 195
 196 const char git_version_string[] = GIT_VERSION;
 197
 198 #define RUN_SETUP       (1<<0)
 199 #define USE_PAGER       (1<<1)
 200
 201 static void handle_internal_command(int argc, const char **argv, char **envp)
 202 {
 203         const char *cmd = argv[0];
 204         static struct cmd_struct {
 205                 const char *cmd;
 206                 int (*fn)(int, const char **, const char *);
 207                 int option;
 208         } commands[] = {
 209                 { "add", cmd_add, RUN_SETUP },
 210                 { "annotate", cmd_annotate, },
 211                 { "apply", cmd_apply },
 212                 { "archive", cmd_archive },
 213                 { "blame", cmd_blame, RUN_SETUP | USE_PAGER },
 214                 { "branch", cmd_branch, RUN_SETUP },
 215                 { "cat-file", cmd_cat_file, RUN_SETUP },
 216                 { "checkout-index", cmd_checkout_index, RUN_SETUP },
 217                 { "check-ref-format", cmd_check_ref_format },
 218                 { "cherry", cmd_cherry, RUN_SETUP },
 219                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
 220                 { "count-objects", cmd_count_objects, RUN_SETUP },
 221                 { "diff", cmd_diff, RUN_SETUP | USE_PAGER },
 222                 { "diff-files", cmd_diff_files, RUN_SETUP },
 223                 { "diff-index", cmd_diff_index, RUN_SETUP },
 224                 { "diff-stages", cmd_diff_stages, RUN_SETUP },
 225                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
 226                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 227                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 228                 { "format-patch", cmd_format_patch, RUN_SETUP },
 229                 { "get-tar-commit-id", cmd_get_tar_commit_id },
 230                 { "grep", cmd_grep, RUN_SETUP },
 231                 { "help", cmd_help },
 232                 { "init-db", cmd_init_db },
 233                 { "log", cmd_log, RUN_SETUP | USE_PAGER },
 234                 { "ls-files", cmd_ls_files, RUN_SETUP },
 235                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
 236                 { "mailinfo", cmd_mailinfo },
 237                 { "mailsplit", cmd_mailsplit },
 238                 { "merge-file", cmd_merge_file },
 239                 { "mv", cmd_mv, RUN_SETUP },
 240                 { "name-rev", cmd_name_rev, RUN_SETUP },
 241                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
 242                 { "pickaxe", cmd_blame, RUN_SETUP | USE_PAGER },
 243                 { "prune", cmd_prune, RUN_SETUP },
 244                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
 245                 { "push", cmd_push, RUN_SETUP },
 246                 { "read-tree", cmd_read_tree, RUN_SETUP },
 247                 { "repo-config", cmd_repo_config },
 248                 { "rev-list", cmd_rev_list, RUN_SETUP },
 249                 { "rev-parse", cmd_rev_parse, RUN_SETUP },
 250                 { "rm", cmd_rm, RUN_SETUP },
 251                 { "runstatus", cmd_runstatus, RUN_SETUP },
 252                 { "shortlog", cmd_shortlog, RUN_SETUP | USE_PAGER },
 253                 { "show-branch", cmd_show_branch, RUN_SETUP },
 254                 { "show", cmd_show, RUN_SETUP | USE_PAGER },
 255                 { "stripspace", cmd_stripspace },
 256                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 257                 { "tar-tree", cmd_tar_tree },
 258                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 259                 { "update-index", cmd_update_index, RUN_SETUP },
 260                 { "update-ref", cmd_update_ref, RUN_SETUP },
 261                 { "upload-archive", cmd_upload_archive },
 262                 { "version", cmd_version },
 263                 { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
 264                 { "write-tree", cmd_write_tree, RUN_SETUP },
 265                 { "verify-pack", cmd_verify_pack },
 266                 { "show-ref", cmd_show_ref, RUN_SETUP },
 267                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
 268         };
 269         int i;
 270
 271         /* Turn "git cmd --help" into "git help cmd" */
 272         if (argc > 1 && !strcmp(argv[1], "--help")) {
 273                 argv[1] = argv[0];
 274                 argv[0] = cmd = "help";
 275         }
 276
 277         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 278                 struct cmd_struct *p = commands+i;
 279                 const char *prefix;
 280                 if (strcmp(p->cmd, cmd))
 281                         continue;
 282
 283                 prefix = NULL;
 284                 if (p->option & RUN_SETUP)
 285                         prefix = setup_git_directory();
 286                 if (p->option & USE_PAGER)
 287                         setup_pager();
 288                 trace_argv_printf(argv, argc, "trace: built-in: git");
 289
 290                 exit(p->fn(argc, argv, prefix));
 291         }
 292 }
 293
 294 int main(int argc, const char **argv, char **envp)
 295 {
 296         const char *cmd = argv[0] ? argv[0] : "git-help";
 297         char *slash = strrchr(cmd, '/');
 298         const char *exec_path = NULL;
 299         int done_alias = 0;
 300
 301         /*
 302          * Take the basename of argv[0] as the command
 303          * name, and the dirname as the default exec_path
 304          * if it's an absolute path and we don't have
 305          * anything better.
 306          */
 307         if (slash) {
 308                 *slash++ = 0;
 309                 if (*cmd == '/')
 310                         exec_path = cmd;
 311                 cmd = slash;
 312         }
 313
 314         /*
 315          * "git-xxxx" is the same as "git xxxx", but we obviously:
 316          *
 317          *  - cannot take flags in between the "git" and the "xxxx".
 318          *  - cannot execute it externally (since it would just do
 319          *    the same thing over again)
 320          *
 321          * So we just directly call the internal command handler, and
 322          * die if that one cannot handle it.
 323          */
 324         if (!strncmp(cmd, "git-", 4)) {
 325                 cmd += 4;
 326                 argv[0] = cmd;
 327                 handle_internal_command(argc, argv, envp);
 328                 die("cannot handle %s internally", cmd);
 329         }
 330
 331         /* Look for flags.. */
 332         argv++;
 333         argc--;
 334         handle_options(&argv, &argc);
 335         if (argc > 0) {
 336                 if (!strncmp(argv[0], "--", 2))
 337                         argv[0] += 2;
 338         } else {
 339                 /* Default command: "help" */
 340                 argv[0] = "help";
 341                 argc = 1;
 342         }
 343         cmd = argv[0];
 344
 345         /*
 346          * We search for git commands in the following order:
 347          *  - git_exec_path()
 348          *  - the path of the "git" command if we could find it
 349          *    in $0
 350          *  - the regular PATH.
 351          */
 352         if (exec_path)
 353                 prepend_to_path(exec_path, strlen(exec_path));
 354         exec_path = git_exec_path();
 355         prepend_to_path(exec_path, strlen(exec_path));
 356
 357         while (1) {
 358                 /* See if it's an internal command */
 359                 handle_internal_command(argc, argv, envp);
 360
 361                 /* .. then try the external ones */
 362                 execv_git_cmd(argv);
 363
 364                 /* It could be an alias -- this works around the insanity
 365                  * of overriding "git log" with "git show" by having
 366                  * alias.log = show
 367                  */
 368                 if (done_alias || !handle_alias(&argc, &argv))
 369                         break;
 370                 done_alias = 1;
 371         }
 372
 373         if (errno == ENOENT)
 374                 help_unknown_cmd(cmd);
 375
 376         fprintf(stderr, "Failed to run command '%s': %s\n",
 377                 cmd, strerror(errno));
 378
 379         return 1;
 380 }