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