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
  15 #include "builtin.h"
  16
  17 static void prepend_to_path(const char *dir, int len)
  18 {
  19         const char *old_path = getenv("PATH");
  20         char *path;
  21         int path_len = len;
  22
  23         if (!old_path)
  24                 old_path = "/usr/local/bin:/usr/bin:/bin";
  25
  26         path_len = len + strlen(old_path) + 1;
  27
  28         path = malloc(path_len + 1);
  29
  30         memcpy(path, dir, len);
  31         path[len] = ':';
  32         memcpy(path + len + 1, old_path, path_len - len);
  33
  34         setenv("PATH", path, 1);
  35 }
  36
  37 static const char *alias_command;
  38 static char *alias_string = NULL;
  39
  40 static int git_alias_config(const char *var, const char *value)
  41 {
  42         if (!strncmp(var, "alias.", 6) && !strcmp(var + 6, alias_command)) {
  43                 alias_string = strdup(value);
  44         }
  45         return 0;
  46 }
  47
  48 static int split_cmdline(char *cmdline, const char ***argv)
  49 {
  50         int src, dst, count = 0, size = 16;
  51         char quoted = 0;
  52
  53         *argv = malloc(sizeof(char*) * size);
  54
  55         /* split alias_string */
  56         (*argv)[count++] = cmdline;
  57         for (src = dst = 0; cmdline[src];) {
  58                 char c = cmdline[src];
  59                 if (!quoted && isspace(c)) {
  60                         cmdline[dst++] = 0;
  61                         while (cmdline[++src]
  62                                         && isspace(cmdline[src]))
  63                                 ; /* skip */
  64                         if (count >= size) {
  65                                 size += 16;
  66                                 *argv = realloc(*argv, sizeof(char*) * size);
  67                         }
  68                         (*argv)[count++] = cmdline + dst;
  69                 } else if(!quoted && (c == '\'' || c == '"')) {
  70                         quoted = c;
  71                         src++;
  72                 } else if (c == quoted) {
  73                         quoted = 0;
  74                         src++;
  75                 } else {
  76                         if (c == '\\' && quoted != '\'') {
  77                                 src++;
  78                                 c = cmdline[src];
  79                                 if (!c) {
  80                                         free(*argv);
  81                                         *argv = NULL;
  82                                         return error("cmdline ends with \\");
  83                                 }
  84                         }
  85                         cmdline[dst++] = c;
  86                         src++;
  87                 }
  88         }
  89
  90         cmdline[dst] = 0;
  91
  92         if (quoted) {
  93                 free(*argv);
  94                 *argv = NULL;
  95                 return error("unclosed quote");
  96         }
  97
  98         return count;
  99 }
 100
 101 static int handle_alias(int *argcp, const char ***argv)
 102 {
 103         int nongit = 0, ret = 0, saved_errno = errno;
 104         const char *subdir;
 105
 106         subdir = setup_git_directory_gently(&nongit);
 107         if (!nongit) {
 108                 int count;
 109                 const char** new_argv;
 110
 111                 alias_command = (*argv)[0];
 112                 git_config(git_alias_config);
 113                 if (alias_string) {
 114
 115                         count = split_cmdline(alias_string, &new_argv);
 116
 117                         if (count < 1)
 118                                 die("empty alias for %s", alias_command);
 119
 120                         if (!strcmp(alias_command, new_argv[0]))
 121                                 die("recursive alias: %s", alias_command);
 122
 123                         /* insert after command name */
 124                         if (*argcp > 1) {
 125                                 new_argv = realloc(new_argv, sizeof(char*) *
 126                                                    (count + *argcp));
 127                                 memcpy(new_argv + count, *argv + 1,
 128                                        sizeof(char*) * *argcp);
 129                         }
 130
 131                         *argv = new_argv;
 132                         *argcp += count - 1;
 133
 134                         ret = 1;
 135                 }
 136         }
 137
 138         if (subdir)
 139                 chdir(subdir);
 140
 141         errno = saved_errno;
 142
 143         return ret;
 144 }
 145
 146 const char git_version_string[] = GIT_VERSION;
 147
 148 static void handle_internal_command(int argc, const char **argv, char **envp)
 149 {
 150         const char *cmd = argv[0];
 151         static struct cmd_struct {
 152                 const char *cmd;
 153                 int (*fn)(int, const char **, char **);
 154         } commands[] = {
 155                 { "version", cmd_version },
 156                 { "help", cmd_help },
 157                 { "log", cmd_log },
 158                 { "whatchanged", cmd_whatchanged },
 159                 { "show", cmd_show },
 160                 { "push", cmd_push },
 161                 { "format-patch", cmd_format_patch },
 162                 { "count-objects", cmd_count_objects },
 163                 { "diff", cmd_diff },
 164                 { "grep", cmd_grep },
 165                 { "rm", cmd_rm },
 166                 { "add", cmd_add },
 167                 { "rev-list", cmd_rev_list },
 168                 { "init-db", cmd_init_db },
 169                 { "get-tar-commit-id", cmd_get_tar_commit_id },
 170                 { "upload-tar", cmd_upload_tar },
 171                 { "check-ref-format", cmd_check_ref_format },
 172                 { "ls-files", cmd_ls_files },
 173                 { "ls-tree", cmd_ls_tree },
 174                 { "tar-tree", cmd_tar_tree },
 175                 { "read-tree", cmd_read_tree },
 176                 { "commit-tree", cmd_commit_tree },
 177                 { "apply", cmd_apply },
 178                 { "show-branch", cmd_show_branch },
 179                 { "diff-files", cmd_diff_files },
 180                 { "diff-index", cmd_diff_index },
 181                 { "diff-stages", cmd_diff_stages },
 182                 { "diff-tree", cmd_diff_tree },
 183                 { "cat-file", cmd_cat_file },
 184                 { "rev-parse", cmd_rev_parse },
 185                 { "write-tree", cmd_write_tree },
 186                 { "mailsplit", cmd_mailsplit },
 187                 { "mailinfo", cmd_mailinfo },
 188                 { "stripspace", cmd_stripspace },
 189                 { "update-index", cmd_update_index },
 190                 { "update-ref", cmd_update_ref },
 191                 { "fmt-merge-msg", cmd_fmt_merge_msg }
 192         };
 193         int i;
 194
 195         /* Turn "git cmd --help" into "git help cmd" */
 196         if (argc > 1 && !strcmp(argv[1], "--help")) {
 197                 argv[1] = argv[0];
 198                 argv[0] = cmd = "help";
 199         }
 200
 201         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 202                 struct cmd_struct *p = commands+i;
 203                 if (strcmp(p->cmd, cmd))
 204                         continue;
 205                 exit(p->fn(argc, argv, envp));
 206         }
 207 }
 208
 209 int main(int argc, const char **argv, char **envp)
 210 {
 211         const char *cmd = argv[0];
 212         char *slash = strrchr(cmd, '/');
 213         const char *exec_path = NULL;
 214         int done_alias = 0;
 215
 216         /*
 217          * Take the basename of argv[0] as the command
 218          * name, and the dirname as the default exec_path
 219          * if it's an absolute path and we don't have
 220          * anything better.
 221          */
 222         if (slash) {
 223                 *slash++ = 0;
 224                 if (*cmd == '/')
 225                         exec_path = cmd;
 226                 cmd = slash;
 227         }
 228
 229         /*
 230          * "git-xxxx" is the same as "git xxxx", but we obviously:
 231          *
 232          *  - cannot take flags in between the "git" and the "xxxx".
 233          *  - cannot execute it externally (since it would just do
 234          *    the same thing over again)
 235          *
 236          * So we just directly call the internal command handler, and
 237          * die if that one cannot handle it.
 238          */
 239         if (!strncmp(cmd, "git-", 4)) {
 240                 cmd += 4;
 241                 argv[0] = cmd;
 242                 handle_internal_command(argc, argv, envp);
 243                 die("cannot handle %s internally", cmd);
 244         }
 245
 246         /* Default command: "help" */
 247         cmd = "help";
 248
 249         /* Look for flags.. */
 250         while (argc > 1) {
 251                 cmd = *++argv;
 252                 argc--;
 253
 254                 if (strncmp(cmd, "--", 2))
 255                         break;
 256
 257                 cmd += 2;
 258
 259                 /*
 260                  * For legacy reasons, the "version" and "help"
 261                  * commands can be written with "--" prepended
 262                  * to make them look like flags.
 263                  */
 264                 if (!strcmp(cmd, "help"))
 265                         break;
 266                 if (!strcmp(cmd, "version"))
 267                         break;
 268
 269                 /*
 270                  * Check remaining flags (which by now must be
 271                  * "--exec-path", but maybe we will accept
 272                  * other arguments some day)
 273                  */
 274                 if (!strncmp(cmd, "exec-path", 9)) {
 275                         cmd += 9;
 276                         if (*cmd == '=') {
 277                                 git_set_exec_path(cmd + 1);
 278                                 continue;
 279                         }
 280                         puts(git_exec_path());
 281                         exit(0);
 282                 }
 283                 cmd_usage(0, NULL, NULL);
 284         }
 285         argv[0] = cmd;
 286
 287         /*
 288          * We search for git commands in the following order:
 289          *  - git_exec_path()
 290          *  - the path of the "git" command if we could find it
 291          *    in $0
 292          *  - the regular PATH.
 293          */
 294         if (exec_path)
 295                 prepend_to_path(exec_path, strlen(exec_path));
 296         exec_path = git_exec_path();
 297         prepend_to_path(exec_path, strlen(exec_path));
 298
 299         while (1) {
 300                 /* See if it's an internal command */
 301                 handle_internal_command(argc, argv, envp);
 302
 303                 /* .. then try the external ones */
 304                 execv_git_cmd(argv);
 305
 306                 /* It could be an alias -- this works around the insanity
 307                  * of overriding "git log" with "git show" by having
 308                  * alias.log = show
 309                  */
 310                 if (done_alias || !handle_alias(&argc, &argv))
 311                         break;
 312                 done_alias = 1;
 313         }
 314
 315         if (errno == ENOENT)
 316                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
 317
 318         fprintf(stderr, "Failed to run command '%s': %s\n",
 319                 cmd, strerror(errno));
 320
 321         return 1;
 322 }