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