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