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 <sys/ioctl.h>
  12 #include "git-compat-util.h"
  13 #include "exec_cmd.h"
  14 #include "common-cmds.h"
  15
  16 #include "cache.h"
  17 #include "commit.h"
  18 #include "revision.h"
  19
  20 #ifndef PATH_MAX
  21 # define PATH_MAX 4096
  22 #endif
  23
  24 static const char git_usage[] =
  25         "Usage: git [--version] [--exec-path[=GIT_EXEC_PATH]] [--help] COMMAND [ ARGS ]";
  26
  27 /* most gui terms set COLUMNS (although some don't export it) */
  28 static int term_columns(void)
  29 {
  30         char *col_string = getenv("COLUMNS");
  31         int n_cols = 0;
  32
  33         if (col_string && (n_cols = atoi(col_string)) > 0)
  34                 return n_cols;
  35
  36 #ifdef TIOCGWINSZ
  37         {
  38                 struct winsize ws;
  39                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
  40                         if (ws.ws_col)
  41                                 return ws.ws_col;
  42                 }
  43         }
  44 #endif
  45
  46         return 80;
  47 }
  48
  49 static void oom(void)
  50 {
  51         fprintf(stderr, "git: out of memory\n");
  52         exit(1);
  53 }
  54
  55 static inline void mput_char(char c, unsigned int num)
  56 {
  57         while(num--)
  58                 putchar(c);
  59 }
  60
  61 static struct cmdname {
  62         size_t len;
  63         char name[1];
  64 } **cmdname;
  65 static int cmdname_alloc, cmdname_cnt;
  66
  67 static void add_cmdname(const char *name, int len)
  68 {
  69         struct cmdname *ent;
  70         if (cmdname_alloc <= cmdname_cnt) {
  71                 cmdname_alloc = cmdname_alloc + 200;
  72                 cmdname = realloc(cmdname, cmdname_alloc * sizeof(*cmdname));
  73                 if (!cmdname)
  74                         oom();
  75         }
  76         ent = malloc(sizeof(*ent) + len);
  77         if (!ent)
  78                 oom();
  79         ent->len = len;
  80         memcpy(ent->name, name, len);
  81         ent->name[len] = 0;
  82         cmdname[cmdname_cnt++] = ent;
  83 }
  84
  85 static int cmdname_compare(const void *a_, const void *b_)
  86 {
  87         struct cmdname *a = *(struct cmdname **)a_;
  88         struct cmdname *b = *(struct cmdname **)b_;
  89         return strcmp(a->name, b->name);
  90 }
  91
  92 static void pretty_print_string_list(struct cmdname **cmdname, int longest)
  93 {
  94         int cols = 1, rows;
  95         int space = longest + 1; /* min 1 SP between words */
  96         int max_cols = term_columns() - 1; /* don't print *on* the edge */
  97         int i, j;
  98
  99         if (space < max_cols)
 100                 cols = max_cols / space;
 101         rows = (cmdname_cnt + cols - 1) / cols;
 102
 103         qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
 104
 105         for (i = 0; i < rows; i++) {
 106                 printf("  ");
 107
 108                 for (j = 0; j < cols; j++) {
 109                         int n = j * rows + i;
 110                         int size = space;
 111                         if (n >= cmdname_cnt)
 112                                 break;
 113                         if (j == cols-1 || n + rows >= cmdname_cnt)
 114                                 size = 1;
 115                         printf("%-*s", size, cmdname[n]->name);
 116                 }
 117                 putchar('\n');
 118         }
 119 }
 120
 121 static void list_commands(const char *exec_path, const char *pattern)
 122 {
 123         unsigned int longest = 0;
 124         char path[PATH_MAX];
 125         int dirlen;
 126         DIR *dir = opendir(exec_path);
 127         struct dirent *de;
 128
 129         if (!dir) {
 130                 fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
 131                 exit(1);
 132         }
 133
 134         dirlen = strlen(exec_path);
 135         if (PATH_MAX - 20 < dirlen) {
 136                 fprintf(stderr, "git: insanely long exec-path '%s'\n",
 137                         exec_path);
 138                 exit(1);
 139         }
 140
 141         memcpy(path, exec_path, dirlen);
 142         path[dirlen++] = '/';
 143
 144         while ((de = readdir(dir)) != NULL) {
 145                 struct stat st;
 146                 int entlen;
 147
 148                 if (strncmp(de->d_name, "git-", 4))
 149                         continue;
 150                 strcpy(path+dirlen, de->d_name);
 151                 if (stat(path, &st) || /* stat, not lstat */
 152                     !S_ISREG(st.st_mode) ||
 153                     !(st.st_mode & S_IXUSR))
 154                         continue;
 155
 156                 entlen = strlen(de->d_name);
 157                 if (4 < entlen && !strcmp(de->d_name + entlen - 4, ".exe"))
 158                         entlen -= 4;
 159
 160                 if (longest < entlen)
 161                         longest = entlen;
 162
 163                 add_cmdname(de->d_name + 4, entlen-4);
 164         }
 165         closedir(dir);
 166
 167         printf("git commands available in '%s'\n", exec_path);
 168         printf("----------------------------");
 169         mput_char('-', strlen(exec_path));
 170         putchar('\n');
 171         pretty_print_string_list(cmdname, longest - 4);
 172         putchar('\n');
 173 }
 174
 175 static void list_common_cmds_help()
 176 {
 177         int i, longest = 0;
 178
 179         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 180                 if (longest < strlen(common_cmds[i].name))
 181                         longest = strlen(common_cmds[i].name);
 182         }
 183
 184         puts("The most commonly used git commands are:");
 185         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 186                 printf("    %s", common_cmds[i].name);
 187                 mput_char(' ', longest - strlen(common_cmds[i].name) + 4);
 188                 puts(common_cmds[i].help);
 189         }
 190         puts("(use 'git help -a' to get a list of all installed git commands)");
 191 }
 192
 193 #ifdef __GNUC__
 194 static void cmd_usage(int show_all, const char *exec_path, const char *fmt, ...)
 195         __attribute__((__format__(__printf__, 3, 4), __noreturn__));
 196 #endif
 197 static void cmd_usage(int show_all, const char *exec_path, const char *fmt, ...)
 198 {
 199         if (fmt) {
 200                 va_list ap;
 201
 202                 va_start(ap, fmt);
 203                 printf("git: ");
 204                 vprintf(fmt, ap);
 205                 va_end(ap);
 206                 putchar('\n');
 207         }
 208         else
 209                 puts(git_usage);
 210
 211         if (exec_path) {
 212                 putchar('\n');
 213                 if (show_all)
 214                         list_commands(exec_path, "git-*");
 215                 else
 216                         list_common_cmds_help();
 217         }
 218
 219         exit(1);
 220 }
 221
 222 static void prepend_to_path(const char *dir, int len)
 223 {
 224         char *path, *old_path = getenv("PATH");
 225         int path_len = len;
 226
 227         if (!old_path)
 228                 old_path = "/usr/local/bin:/usr/bin:/bin";
 229
 230         path_len = len + strlen(old_path) + 1;
 231
 232         path = malloc(path_len + 1);
 233
 234         memcpy(path, dir, len);
 235         path[len] = ':';
 236         memcpy(path + len + 1, old_path, path_len - len);
 237
 238         setenv("PATH", path, 1);
 239 }
 240
 241 static void show_man_page(const char *git_cmd)
 242 {
 243         const char *page;
 244
 245         if (!strncmp(git_cmd, "git", 3))
 246                 page = git_cmd;
 247         else {
 248                 int page_len = strlen(git_cmd) + 4;
 249                 char *p = malloc(page_len + 1);
 250                 strcpy(p, "git-");
 251                 strcpy(p + 4, git_cmd);
 252                 p[page_len] = 0;
 253                 page = p;
 254         }
 255
 256         execlp("man", "man", page, NULL);
 257 }
 258
 259 static int cmd_version(int argc, const char **argv, char **envp)
 260 {
 261         printf("git version %s\n", GIT_VERSION);
 262         return 0;
 263 }
 264
 265 static int cmd_help(int argc, const char **argv, char **envp)
 266 {
 267         const char *help_cmd = argv[1];
 268         if (!help_cmd)
 269                 cmd_usage(0, git_exec_path(), NULL);
 270         else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a"))
 271                 cmd_usage(1, git_exec_path(), NULL);
 272         else
 273                 show_man_page(help_cmd);
 274         return 0;
 275 }
 276
 277 #define LOGSIZE (65536)
 278
 279 static int cmd_log(int argc, const char **argv, char **envp)
 280 {
 281         struct rev_info rev;
 282         struct commit *commit;
 283         char *buf = xmalloc(LOGSIZE);
 284         static enum cmit_fmt commit_format = CMIT_FMT_DEFAULT;
 285         int abbrev = DEFAULT_ABBREV;
 286         int show_parents = 0;
 287         const char *commit_prefix = "commit ";
 288
 289         argc = setup_revisions(argc, argv, &rev, "HEAD");
 290         while (1 < argc) {
 291                 const char *arg = argv[1];
 292                 if (!strncmp(arg, "--pretty", 8)) {
 293                         commit_format = get_commit_format(arg + 8);
 294                         if (commit_format == CMIT_FMT_ONELINE)
 295                                 commit_prefix = "";
 296                 }
 297                 else if (!strcmp(arg, "--parents")) {
 298                         show_parents = 1;
 299                 }
 300                 else if (!strcmp(arg, "--no-abbrev")) {
 301                         abbrev = 0;
 302                 }
 303                 else if (!strncmp(arg, "--abbrev=", 9)) {
 304                         abbrev = strtoul(arg + 9, NULL, 10);
 305                         if (abbrev && abbrev < MINIMUM_ABBREV)
 306                                 abbrev = MINIMUM_ABBREV;
 307                         else if (40 < abbrev)
 308                                 abbrev = 40;
 309                 }
 310                 else
 311                         die("unrecognized argument: %s", arg);
 312                 argc--; argv++;
 313         }
 314
 315         prepare_revision_walk(&rev);
 316         setup_pager();
 317         while ((commit = get_revision(&rev)) != NULL) {
 318                 printf("%s%s", commit_prefix,
 319                        sha1_to_hex(commit->object.sha1));
 320                 if (show_parents) {
 321                         struct commit_list *parents = commit->parents;
 322                         while (parents) {
 323                                 struct object *o = &(parents->item->object);
 324                                 parents = parents->next;
 325                                 if (o->flags & TMP_MARK)
 326                                         continue;
 327                                 printf(" %s", sha1_to_hex(o->sha1));
 328                                 o->flags |= TMP_MARK;
 329                         }
 330                         /* TMP_MARK is a general purpose flag that can
 331                          * be used locally, but the user should clean
 332                          * things up after it is done with them.
 333                          */
 334                         for (parents = commit->parents;
 335                              parents;
 336                              parents = parents->next)
 337                                 parents->item->object.flags &= ~TMP_MARK;
 338                 }
 339                 if (commit_format == CMIT_FMT_ONELINE)
 340                         putchar(' ');
 341                 else
 342                         putchar('\n');
 343                 pretty_print_commit(commit_format, commit, ~0, buf,
 344                                     LOGSIZE, abbrev);
 345                 printf("%s\n", buf);
 346         }
 347         free(buf);
 348         return 0;
 349 }
 350
 351 static void handle_internal_command(int argc, const char **argv, char **envp)
 352 {
 353         const char *cmd = argv[0];
 354         static struct cmd_struct {
 355                 const char *cmd;
 356                 int (*fn)(int, const char **, char **);
 357         } commands[] = {
 358                 { "version", cmd_version },
 359                 { "help", cmd_help },
 360                 { "log", cmd_log },
 361         };
 362         int i;
 363
 364         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 365                 struct cmd_struct *p = commands+i;
 366                 if (strcmp(p->cmd, cmd))
 367                         continue;
 368                 exit(p->fn(argc, argv, envp));
 369         }
 370 }
 371
 372 int main(int argc, const char **argv, char **envp)
 373 {
 374         const char *cmd = argv[0];
 375         char *slash = strrchr(cmd, '/');
 376         char git_command[PATH_MAX + 1];
 377         const char *exec_path = NULL;
 378
 379         /*
 380          * Take the basename of argv[0] as the command
 381          * name, and the dirname as the default exec_path
 382          * if it's an absolute path and we don't have
 383          * anything better.
 384          */
 385         if (slash) {
 386                 *slash++ = 0;
 387                 if (*cmd == '/')
 388                         exec_path = cmd;
 389                 cmd = slash;
 390         }
 391
 392         /*
 393          * "git-xxxx" is the same as "git xxxx", but we obviously:
 394          *
 395          *  - cannot take flags in between the "git" and the "xxxx".
 396          *  - cannot execute it externally (since it would just do
 397          *    the same thing over again)
 398          *
 399          * So we just directly call the internal command handler, and
 400          * die if that one cannot handle it.
 401          */
 402         if (!strncmp(cmd, "git-", 4)) {
 403                 cmd += 4;
 404                 argv[0] = cmd;
 405                 handle_internal_command(argc, argv, envp);
 406                 die("cannot handle %s internally", cmd);
 407         }
 408
 409         /* Default command: "help" */
 410         cmd = "help";
 411
 412         /* Look for flags.. */
 413         while (argc > 1) {
 414                 cmd = *++argv;
 415                 argc--;
 416
 417                 if (strncmp(cmd, "--", 2))
 418                         break;
 419
 420                 cmd += 2;
 421
 422                 /*
 423                  * For legacy reasons, the "version" and "help"
 424                  * commands can be written with "--" prepended
 425                  * to make them look like flags.
 426                  */
 427                 if (!strcmp(cmd, "help"))
 428                         break;
 429                 if (!strcmp(cmd, "version"))
 430                         break;
 431
 432                 /*
 433                  * Check remaining flags (which by now must be
 434                  * "--exec-path", but maybe we will accept
 435                  * other arguments some day)
 436                  */
 437                 if (!strncmp(cmd, "exec-path", 9)) {
 438                         cmd += 9;
 439                         if (*cmd == '=') {
 440                                 git_set_exec_path(cmd + 1);
 441                                 continue;
 442                         }
 443                         puts(git_exec_path());
 444                         exit(0);
 445                 }
 446                 cmd_usage(0, NULL, NULL);
 447         }
 448         argv[0] = cmd;
 449
 450         /*
 451          * We search for git commands in the following order:
 452          *  - git_exec_path()
 453          *  - the path of the "git" command if we could find it
 454          *    in $0
 455          *  - the regular PATH.
 456          */
 457         if (exec_path)
 458                 prepend_to_path(exec_path, strlen(exec_path));
 459         exec_path = git_exec_path();
 460         prepend_to_path(exec_path, strlen(exec_path));
 461
 462         /* See if it's an internal command */
 463         handle_internal_command(argc, argv, envp);
 464
 465         /* .. then try the external ones */
 466         execv_git_cmd(argv);
 467
 468         if (errno == ENOENT)
 469                 cmd_usage(0, exec_path, "'%s' is not a git-command", cmd);
 470
 471         fprintf(stderr, "Failed to run command '%s': %s\n",
 472                 git_command, strerror(errno));
 473
 474         return 1;
 475 }