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 #include "cache.h"
  14 #include "quote.h"
  15
  16 #include "builtin.h"
  17
  18 const char git_usage_string[] =
  19         "git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
  20
  21 static void prepend_to_path(const char *dir, int len)
  22 {
  23         const char *old_path = getenv("PATH");
  24         char *path;
  25         int path_len = len;
  26
  27         if (!old_path)
  28                 old_path = "/usr/local/bin:/usr/bin:/bin";
  29
  30         path_len = len + strlen(old_path) + 1;
  31
  32         path = malloc(path_len + 1);
  33
  34         memcpy(path, dir, len);
  35         path[len] = ':';
  36         memcpy(path + len + 1, old_path, path_len - len);
  37
  38         setenv("PATH", path, 1);
  39 }
  40
  41 static int handle_options(const char*** argv, int* argc)
  42 {
  43         int handled = 0;
  44
  45         while (*argc > 0) {
  46                 const char *cmd = (*argv)[0];
  47                 if (cmd[0] != '-')
  48                         break;
  49
  50                 /*
  51                  * For legacy reasons, the "version" and "help"
  52                  * commands can be written with "--" prepended
  53                  * to make them look like flags.
  54                  */
  55                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  56                         break;
  57
  58                 /*
  59                  * Check remaining flags.
  60                  */
  61                 if (!strncmp(cmd, "--exec-path", 11)) {
  62                         cmd += 11;
  63                         if (*cmd == '=')
  64                                 git_set_exec_path(cmd + 1);
  65                         else {
  66                                 puts(git_exec_path());
  67                                 exit(0);
  68                         }
  69                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  70                         setup_pager();
  71                 } else if (!strcmp(cmd, "--git-dir")) {
  72                         if (*argc < 1)
  73                                 return -1;
  74                         setenv("GIT_DIR", (*argv)[1], 1);
  75                         (*argv)++;
  76                         (*argc)--;
  77                 } else if (!strncmp(cmd, "--git-dir=", 10)) {
  78                         setenv("GIT_DIR", cmd + 10, 1);
  79                 } else if (!strcmp(cmd, "--bare")) {
  80                         static char git_dir[1024];
  81                         setenv("GIT_DIR", getcwd(git_dir, 1024), 1);
  82                 } else {
  83                         fprintf(stderr, "Unknown option: %s\n", cmd);
  84                         usage(git_usage_string);
  85                 }
  86
  87                 (*argv)++;
  88                 (*argc)--;
  89                 handled++;
  90         }
  91         return handled;
  92 }
  93
  94 static const char *alias_command;
  95 static char *alias_string = NULL;
  96
  97 static int git_alias_config(const char *var, const char *value)
  98 {
  99         if (!strncmp(var, "alias.", 6) && !strcmp(var + 6, alias_command)) {
 100                 alias_string = strdup(value);
 101         }
 102         return 0;
 103 }
 104
 105 static int split_cmdline(char *cmdline, const char ***argv)
 106 {
 107         int src, dst, count = 0, size = 16;
 108         char quoted = 0;
 109
 110         *argv = malloc(sizeof(char*) * size);
 111
 112         /* split alias_string */
 113         (*argv)[count++] = cmdline;
 114         for (src = dst = 0; cmdline[src];) {
 115                 char c = cmdline[src];
 116                 if (!quoted && isspace(c)) {
 117                         cmdline[dst++] = 0;
 118                         while (cmdline[++src]
 119                                         && isspace(cmdline[src]))
 120                                 ; /* skip */
 121                         if (count >= size) {
 122                                 size += 16;
 123                                 *argv = realloc(*argv, sizeof(char*) * size);
 124                         }
 125                         (*argv)[count++] = cmdline + dst;
 126                 } else if(!quoted && (c == '\'' || c == '"')) {
 127                         quoted = c;
 128                         src++;
 129                 } else if (c == quoted) {
 130                         quoted = 0;
 131                         src++;
 132                 } else {
 133                         if (c == '\\' && quoted != '\'') {
 134                                 src++;
 135                                 c = cmdline[src];
 136                                 if (!c) {
 137                                         free(*argv);
 138                                         *argv = NULL;
 139                                         return error("cmdline ends with \\");
 140                                 }
 141                         }
 142                         cmdline[dst++] = c;
 143                         src++;
 144                 }
 145         }
 146
 147         cmdline[dst] = 0;
 148
 149         if (quoted) {
 150                 free(*argv);
 151                 *argv = NULL;
 152                 return error("unclosed quote");
 153         }
 154
 155         return count;
 156 }
 157
 158 static int handle_alias(int *argcp, const char ***argv)
 159 {
 160         int nongit = 0, ret = 0, saved_errno = errno;
 161         const char *subdir;
 162         int count, option_count;
 163         const char** new_argv;
 164
 165         subdir = setup_git_directory_gently(&nongit);
 166
 167         alias_command = (*argv)[0];
 168         git_config(git_alias_config);
 169         if (alias_string) {
 170                 count = split_cmdline(alias_string, &new_argv);
 171                 option_count = handle_options(&new_argv, &count);
 172                 memmove(new_argv - option_count, new_argv,
 173                                 count * sizeof(char *));
 174                 new_argv -= option_count;
 175
 176                 if (count < 1)
 177                         die("empty alias for %s", alias_command);
 178
 179                 if (!strcmp(alias_command, new_argv[0]))
 180                         die("recursive alias: %s", alias_command);
 181
 182                 if (getenv("GIT_TRACE")) {
 183                         int i;
 184                         fprintf(stderr, "trace: alias expansion: %s =>",
 185                                 alias_command);
 186                         for (i = 0; i < count; ++i) {
 187                                 fputc(' ', stderr);
 188                                 sq_quote_print(stderr, new_argv[i]);
 189                         }
 190                         fputc('\n', stderr);
 191                         fflush(stderr);
 192                 }
 193
 194                 new_argv = realloc(new_argv, sizeof(char*) *
 195                                    (count + *argcp + 1));
 196                 /* insert after command name */
 197                 memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
 198                 new_argv[count+*argcp] = NULL;
 199
 200                 *argv = new_argv;
 201                 *argcp += count - 1;
 202
 203                 ret = 1;
 204         }
 205
 206         if (subdir)
 207                 chdir(subdir);
 208
 209         errno = saved_errno;
 210
 211         return ret;
 212 }
 213
 214 const char git_version_string[] = GIT_VERSION;
 215
 216 #define RUN_SETUP       (1<<0)
 217 #define USE_PAGER       (1<<1)
 218
 219 static void handle_internal_command(int argc, const char **argv, char **envp)
 220 {
 221         const char *cmd = argv[0];
 222         static struct cmd_struct {
 223                 const char *cmd;
 224                 int (*fn)(int, const char **, const char *);
 225                 int option;
 226         } commands[] = {
 227                 { "add", cmd_add, RUN_SETUP },
 228                 { "apply", cmd_apply },
 229                 { "cat-file", cmd_cat_file, RUN_SETUP },
 230                 { "checkout-index", cmd_checkout_index, RUN_SETUP },
 231                 { "check-ref-format", cmd_check_ref_format },
 232                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
 233                 { "count-objects", cmd_count_objects },
 234                 { "diff", cmd_diff, RUN_SETUP },
 235                 { "diff-files", cmd_diff_files, RUN_SETUP },
 236                 { "diff-index", cmd_diff_index, RUN_SETUP },
 237                 { "diff-stages", cmd_diff_stages, RUN_SETUP },
 238                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
 239                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 240                 { "format-patch", cmd_format_patch, RUN_SETUP },
 241                 { "get-tar-commit-id", cmd_get_tar_commit_id },
 242                 { "grep", cmd_grep, RUN_SETUP },
 243                 { "help", cmd_help },
 244                 { "init-db", cmd_init_db },
 245                 { "log", cmd_log, RUN_SETUP | USE_PAGER },
 246                 { "ls-files", cmd_ls_files, RUN_SETUP },
 247                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
 248                 { "mailinfo", cmd_mailinfo },
 249                 { "mailsplit", cmd_mailsplit },
 250                 { "mv", cmd_mv, RUN_SETUP },
 251                 { "name-rev", cmd_name_rev, RUN_SETUP },
 252                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
 253                 { "prune", cmd_prune, RUN_SETUP },
 254                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
 255                 { "push", cmd_push },
 256                 { "read-tree", cmd_read_tree, RUN_SETUP },
 257                 { "repo-config", cmd_repo_config },
 258                 { "rev-list", cmd_rev_list, RUN_SETUP },
 259                 { "rev-parse", cmd_rev_parse, RUN_SETUP },
 260                 { "rm", cmd_rm, RUN_SETUP },
 261                 { "show-branch", cmd_show_branch, RUN_SETUP },
 262                 { "show", cmd_show, RUN_SETUP | USE_PAGER },
 263                 { "stripspace", cmd_stripspace },
 264                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 265                 { "tar-tree", cmd_tar_tree, RUN_SETUP },
 266                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 267                 { "update-index", cmd_update_index, RUN_SETUP },
 268                 { "update-ref", cmd_update_ref, RUN_SETUP },
 269                 { "upload-tar", cmd_upload_tar },
 270                 { "version", cmd_version },
 271                 { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
 272                 { "write-tree", cmd_write_tree, RUN_SETUP },
 273         };
 274         int i;
 275
 276         /* Turn "git cmd --help" into "git help cmd" */
 277         if (argc > 1 && !strcmp(argv[1], "--help")) {
 278                 argv[1] = argv[0];
 279                 argv[0] = cmd = "help";
 280         }
 281
 282         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 283                 struct cmd_struct *p = commands+i;
 284                 const char *prefix;
 285                 if (strcmp(p->cmd, cmd))
 286                         continue;
 287
 288                 prefix = NULL;
 289                 if (p->option & RUN_SETUP)
 290                         prefix = setup_git_directory();
 291                 if (p->option & USE_PAGER)
 292                         setup_pager();
 293                 if (getenv("GIT_TRACE")) {
 294                         int i;
 295                         fprintf(stderr, "trace: built-in: git");
 296                         for (i = 0; i < argc; ++i) {
 297                                 fputc(' ', stderr);
 298                                 sq_quote_print(stderr, argv[i]);
 299                         }
 300                         putc('\n', stderr);
 301                         fflush(stderr);
 302                 }
 303
 304                 exit(p->fn(argc, argv, prefix));
 305         }
 306 }
 307
 308 int main(int argc, const char **argv, char **envp)
 309 {
 310         const char *cmd = argv[0];
 311         char *slash = strrchr(cmd, '/');
 312         const char *exec_path = NULL;
 313         int done_alias = 0;
 314
 315         /*
 316          * Take the basename of argv[0] as the command
 317          * name, and the dirname as the default exec_path
 318          * if it's an absolute path and we don't have
 319          * anything better.
 320          */
 321         if (slash) {
 322                 *slash++ = 0;
 323                 if (*cmd == '/')
 324                         exec_path = cmd;
 325                 cmd = slash;
 326         }
 327
 328         /*
 329          * "git-xxxx" is the same as "git xxxx", but we obviously:
 330          *
 331          *  - cannot take flags in between the "git" and the "xxxx".
 332          *  - cannot execute it externally (since it would just do
 333          *    the same thing over again)
 334          *
 335          * So we just directly call the internal command handler, and
 336          * die if that one cannot handle it.
 337          */
 338         if (!strncmp(cmd, "git-", 4)) {
 339                 cmd += 4;
 340                 argv[0] = cmd;
 341                 handle_internal_command(argc, argv, envp);
 342                 die("cannot handle %s internally", cmd);
 343         }
 344
 345         /* Look for flags.. */
 346         argv++;
 347         argc--;
 348         handle_options(&argv, &argc);
 349         if (argc > 0) {
 350                 if (!strncmp(argv[0], "--", 2))
 351                         argv[0] += 2;
 352         } else {
 353                 /* Default command: "help" */
 354                 argv[0] = "help";
 355                 argc = 1;
 356         }
 357         cmd = argv[0];
 358
 359         /*
 360          * We search for git commands in the following order:
 361          *  - git_exec_path()
 362          *  - the path of the "git" command if we could find it
 363          *    in $0
 364          *  - the regular PATH.
 365          */
 366         if (exec_path)
 367                 prepend_to_path(exec_path, strlen(exec_path));
 368         exec_path = git_exec_path();
 369         prepend_to_path(exec_path, strlen(exec_path));
 370
 371         while (1) {
 372                 /* See if it's an internal command */
 373                 handle_internal_command(argc, argv, envp);
 374
 375                 /* .. then try the external ones */
 376                 execv_git_cmd(argv);
 377
 378                 /* It could be an alias -- this works around the insanity
 379                  * of overriding "git log" with "git show" by having
 380                  * alias.log = show
 381                  */
 382                 if (done_alias || !handle_alias(&argc, &argv))
 383                         break;
 384                 done_alias = 1;
 385         }
 386
 387         if (errno == ENOENT)
 388                 help_unknown_cmd(cmd);
 389
 390         fprintf(stderr, "Failed to run command '%s': %s\n",
 391                 cmd, strerror(errno));
 392
 393         return 1;
 394 }