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