Andrew's git - gitweb.git/blob

   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
  18const char git_usage_string[] =
  19        "git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
  20
  21static 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
  41static 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
  94static const char *alias_command;
  95static char *alias_string = NULL;
  96
  97static 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
 105static 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
 158static 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
 214const char git_version_string[] = GIT_VERSION;
 215
 216#define NEEDS_PREFIX 1
 217#define USE_PAGER 2
 218
 219static 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                { "version", cmd_version },
 228                { "help", cmd_help },
 229                { "log", cmd_log, NEEDS_PREFIX | USE_PAGER },
 230                { "whatchanged", cmd_whatchanged, NEEDS_PREFIX | USE_PAGER },
 231                { "show", cmd_show, NEEDS_PREFIX | USE_PAGER },
 232                { "push", cmd_push },
 233                { "format-patch", cmd_format_patch, NEEDS_PREFIX },
 234                { "count-objects", cmd_count_objects },
 235                { "diff", cmd_diff, NEEDS_PREFIX },
 236                { "grep", cmd_grep, NEEDS_PREFIX },
 237                { "rm", cmd_rm, NEEDS_PREFIX },
 238                { "add", cmd_add, NEEDS_PREFIX },
 239                { "rev-list", cmd_rev_list, NEEDS_PREFIX },
 240                { "init-db", cmd_init_db },
 241                { "get-tar-commit-id", cmd_get_tar_commit_id },
 242                { "upload-tar", cmd_upload_tar },
 243                { "check-ref-format", cmd_check_ref_format },
 244                { "ls-files", cmd_ls_files, NEEDS_PREFIX },
 245                { "ls-tree", cmd_ls_tree, NEEDS_PREFIX },
 246                { "tar-tree", cmd_tar_tree, NEEDS_PREFIX },
 247                { "read-tree", cmd_read_tree, NEEDS_PREFIX },
 248                { "commit-tree", cmd_commit_tree, NEEDS_PREFIX },
 249                { "apply", cmd_apply },
 250                { "show-branch", cmd_show_branch, NEEDS_PREFIX },
 251                { "diff-files", cmd_diff_files, NEEDS_PREFIX },
 252                { "diff-index", cmd_diff_index, NEEDS_PREFIX },
 253                { "diff-stages", cmd_diff_stages, NEEDS_PREFIX },
 254                { "diff-tree", cmd_diff_tree, NEEDS_PREFIX },
 255                { "cat-file", cmd_cat_file, NEEDS_PREFIX },
 256                { "rev-parse", cmd_rev_parse, NEEDS_PREFIX },
 257                { "write-tree", cmd_write_tree, NEEDS_PREFIX },
 258                { "mailsplit", cmd_mailsplit },
 259                { "mailinfo", cmd_mailinfo },
 260                { "stripspace", cmd_stripspace },
 261                { "update-index", cmd_update_index, NEEDS_PREFIX },
 262                { "update-ref", cmd_update_ref, NEEDS_PREFIX },
 263                { "fmt-merge-msg", cmd_fmt_merge_msg, NEEDS_PREFIX },
 264                { "prune", cmd_prune, NEEDS_PREFIX },
 265                { "mv", cmd_mv, NEEDS_PREFIX },
 266                { "prune-packed", cmd_prune_packed, NEEDS_PREFIX },
 267                { "repo-config", cmd_repo_config },
 268        };
 269        int i;
 270
 271        /* Turn "git cmd --help" into "git help cmd" */
 272        if (argc > 1 && !strcmp(argv[1], "--help")) {
 273                argv[1] = argv[0];
 274                argv[0] = cmd = "help";
 275        }
 276
 277        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 278                struct cmd_struct *p = commands+i;
 279                const char *prefix;
 280                if (strcmp(p->cmd, cmd))
 281                        continue;
 282
 283                prefix = NULL;
 284                if (p->option & NEEDS_PREFIX)
 285                        prefix = setup_git_directory();
 286                if (p->option & USE_PAGER)
 287                        setup_pager();
 288                if (getenv("GIT_TRACE")) {
 289                        int i;
 290                        fprintf(stderr, "trace: built-in: git");
 291                        for (i = 0; i < argc; ++i) {
 292                                fputc(' ', stderr);
 293                                sq_quote_print(stderr, argv[i]);
 294                        }
 295                        putc('\n', stderr);
 296                        fflush(stderr);
 297                }
 298
 299                exit(p->fn(argc, argv, prefix));
 300        }
 301}
 302
 303int main(int argc, const char **argv, char **envp)
 304{
 305        const char *cmd = argv[0];
 306        char *slash = strrchr(cmd, '/');
 307        const char *exec_path = NULL;
 308        int done_alias = 0;
 309
 310        /*
 311         * Take the basename of argv[0] as the command
 312         * name, and the dirname as the default exec_path
 313         * if it's an absolute path and we don't have
 314         * anything better.
 315         */
 316        if (slash) {
 317                *slash++ = 0;
 318                if (*cmd == '/')
 319                        exec_path = cmd;
 320                cmd = slash;
 321        }
 322
 323        /*
 324         * "git-xxxx" is the same as "git xxxx", but we obviously:
 325         *
 326         *  - cannot take flags in between the "git" and the "xxxx".
 327         *  - cannot execute it externally (since it would just do
 328         *    the same thing over again)
 329         *
 330         * So we just directly call the internal command handler, and
 331         * die if that one cannot handle it.
 332         */
 333        if (!strncmp(cmd, "git-", 4)) {
 334                cmd += 4;
 335                argv[0] = cmd;
 336                handle_internal_command(argc, argv, envp);
 337                die("cannot handle %s internally", cmd);
 338        }
 339
 340        /* Look for flags.. */
 341        argv++;
 342        argc--;
 343        handle_options(&argv, &argc);
 344        if (argc > 0) {
 345                if (!strncmp(argv[0], "--", 2))
 346                        argv[0] += 2;
 347        } else {
 348                /* Default command: "help" */
 349                argv[0] = "help";
 350                argc = 1;
 351        }
 352        cmd = argv[0];
 353
 354        /*
 355         * We search for git commands in the following order:
 356         *  - git_exec_path()
 357         *  - the path of the "git" command if we could find it
 358         *    in $0
 359         *  - the regular PATH.
 360         */
 361        if (exec_path)
 362                prepend_to_path(exec_path, strlen(exec_path));
 363        exec_path = git_exec_path();
 364        prepend_to_path(exec_path, strlen(exec_path));
 365
 366        while (1) {
 367                /* See if it's an internal command */
 368                handle_internal_command(argc, argv, envp);
 369
 370                /* .. then try the external ones */
 371                execv_git_cmd(argv);
 372
 373                /* It could be an alias -- this works around the insanity
 374                 * of overriding "git log" with "git show" by having
 375                 * alias.log = show
 376                 */
 377                if (done_alias || !handle_alias(&argc, &argv))
 378                        break;
 379                done_alias = 1;
 380        }
 381
 382        if (errno == ENOENT)
 383                help_unknown_cmd(cmd);
 384
 385        fprintf(stderr, "Failed to run command '%s': %s\n",
 386                cmd, strerror(errno));
 387
 388        return 1;
 389}