help.c

   1 /*
   2  * builtin-help.c
   3  *
   4  * Builtin help-related commands (help, usage, version)
   5  */
   6 #include "cache.h"
   7 #include "builtin.h"
   8 #include "exec_cmd.h"
   9 #include "common-cmds.h"
  10
  11 static const char *help_default_format;
  12
  13 static enum help_format {
  14         man_format,
  15         info_format,
  16         web_format,
  17 } help_format = man_format;
  18
  19 static void parse_help_format(const char *format)
  20 {
  21         if (!format) {
  22                 help_format = man_format;
  23                 return;
  24         }
  25         if (!strcmp(format, "man")) {
  26                 help_format = man_format;
  27                 return;
  28         }
  29         if (!strcmp(format, "info")) {
  30                 help_format = info_format;
  31                 return;
  32         }
  33         if (!strcmp(format, "web") || !strcmp(format, "html")) {
  34                 help_format = web_format;
  35                 return;
  36         }
  37         die("unrecognized help format '%s'", format);
  38 }
  39
  40 static int git_help_config(const char *var, const char *value)
  41 {
  42         if (!strcmp(var, "help.format")) {
  43                 if (!value)
  44                         return config_error_nonbool(var);
  45                 help_default_format = xstrdup(value);
  46                 return 0;
  47         }
  48         return git_default_config(var, value);
  49 }
  50
  51 /* most GUI terminals set COLUMNS (although some don't export it) */
  52 static int term_columns(void)
  53 {
  54         char *col_string = getenv("COLUMNS");
  55         int n_cols;
  56
  57         if (col_string && (n_cols = atoi(col_string)) > 0)
  58                 return n_cols;
  59
  60 #ifdef TIOCGWINSZ
  61         {
  62                 struct winsize ws;
  63                 if (!ioctl(1, TIOCGWINSZ, &ws)) {
  64                         if (ws.ws_col)
  65                                 return ws.ws_col;
  66                 }
  67         }
  68 #endif
  69
  70         return 80;
  71 }
  72
  73 static inline void mput_char(char c, unsigned int num)
  74 {
  75         while(num--)
  76                 putchar(c);
  77 }
  78
  79 static struct cmdnames {
  80         int alloc;
  81         int cnt;
  82         struct cmdname {
  83                 size_t len;
  84                 char name[1];
  85         } **names;
  86 } main_cmds, other_cmds;
  87
  88 static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
  89 {
  90         struct cmdname *ent = xmalloc(sizeof(*ent) + len);
  91
  92         ent->len = len;
  93         memcpy(ent->name, name, len);
  94         ent->name[len] = 0;
  95
  96         ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  97         cmds->names[cmds->cnt++] = ent;
  98 }
  99
 100 static int cmdname_compare(const void *a_, const void *b_)
 101 {
 102         struct cmdname *a = *(struct cmdname **)a_;
 103         struct cmdname *b = *(struct cmdname **)b_;
 104         return strcmp(a->name, b->name);
 105 }
 106
 107 static void uniq(struct cmdnames *cmds)
 108 {
 109         int i, j;
 110
 111         if (!cmds->cnt)
 112                 return;
 113
 114         for (i = j = 1; i < cmds->cnt; i++)
 115                 if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
 116                         cmds->names[j++] = cmds->names[i];
 117
 118         cmds->cnt = j;
 119 }
 120
 121 static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 122 {
 123         int ci, cj, ei;
 124         int cmp;
 125
 126         ci = cj = ei = 0;
 127         while (ci < cmds->cnt && ei < excludes->cnt) {
 128                 cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
 129                 if (cmp < 0)
 130                         cmds->names[cj++] = cmds->names[ci++];
 131                 else if (cmp == 0)
 132                         ci++, ei++;
 133                 else if (cmp > 0)
 134                         ei++;
 135         }
 136
 137         while (ci < cmds->cnt)
 138                 cmds->names[cj++] = cmds->names[ci++];
 139
 140         cmds->cnt = cj;
 141 }
 142
 143 static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 144 {
 145         int cols = 1, rows;
 146         int space = longest + 1; /* min 1 SP between words */
 147         int max_cols = term_columns() - 1; /* don't print *on* the edge */
 148         int i, j;
 149
 150         if (space < max_cols)
 151                 cols = max_cols / space;
 152         rows = (cmds->cnt + cols - 1) / cols;
 153
 154         for (i = 0; i < rows; i++) {
 155                 printf("  ");
 156
 157                 for (j = 0; j < cols; j++) {
 158                         int n = j * rows + i;
 159                         int size = space;
 160                         if (n >= cmds->cnt)
 161                                 break;
 162                         if (j == cols-1 || n + rows >= cmds->cnt)
 163                                 size = 1;
 164                         printf("%-*s", size, cmds->names[n]->name);
 165                 }
 166                 putchar('\n');
 167         }
 168 }
 169
 170 static unsigned int list_commands_in_dir(struct cmdnames *cmds,
 171                                          const char *path)
 172 {
 173         unsigned int longest = 0;
 174         const char *prefix = "git-";
 175         int prefix_len = strlen(prefix);
 176         DIR *dir = opendir(path);
 177         struct dirent *de;
 178
 179         if (!dir || chdir(path))
 180                 return 0;
 181
 182         while ((de = readdir(dir)) != NULL) {
 183                 struct stat st;
 184                 int entlen;
 185
 186                 if (prefixcmp(de->d_name, prefix))
 187                         continue;
 188
 189                 if (stat(de->d_name, &st) || /* stat, not lstat */
 190                     !S_ISREG(st.st_mode) ||
 191                     !(st.st_mode & S_IXUSR))
 192                         continue;
 193
 194                 entlen = strlen(de->d_name) - prefix_len;
 195                 if (has_extension(de->d_name, ".exe"))
 196                         entlen -= 4;
 197
 198                 if (longest < entlen)
 199                         longest = entlen;
 200
 201                 add_cmdname(cmds, de->d_name + prefix_len, entlen);
 202         }
 203         closedir(dir);
 204
 205         return longest;
 206 }
 207
 208 static void list_commands(void)
 209 {
 210         unsigned int longest = 0;
 211         unsigned int len;
 212         const char *env_path = getenv("PATH");
 213         char *paths, *path, *colon;
 214         const char *exec_path = git_exec_path();
 215
 216         if (exec_path)
 217                 longest = list_commands_in_dir(&main_cmds, exec_path);
 218
 219         if (!env_path) {
 220                 fprintf(stderr, "PATH not set\n");
 221                 exit(1);
 222         }
 223
 224         path = paths = xstrdup(env_path);
 225         while (1) {
 226                 if ((colon = strchr(path, ':')))
 227                         *colon = 0;
 228
 229                 len = list_commands_in_dir(&other_cmds, path);
 230                 if (len > longest)
 231                         longest = len;
 232
 233                 if (!colon)
 234                         break;
 235                 path = colon + 1;
 236         }
 237         free(paths);
 238
 239         qsort(main_cmds.names, main_cmds.cnt,
 240               sizeof(*main_cmds.names), cmdname_compare);
 241         uniq(&main_cmds);
 242
 243         qsort(other_cmds.names, other_cmds.cnt,
 244               sizeof(*other_cmds.names), cmdname_compare);
 245         uniq(&other_cmds);
 246         exclude_cmds(&other_cmds, &main_cmds);
 247
 248         if (main_cmds.cnt) {
 249                 printf("available git commands in '%s'\n", exec_path);
 250                 printf("----------------------------");
 251                 mput_char('-', strlen(exec_path));
 252                 putchar('\n');
 253                 pretty_print_string_list(&main_cmds, longest);
 254                 putchar('\n');
 255         }
 256
 257         if (other_cmds.cnt) {
 258                 printf("git commands available from elsewhere on your $PATH\n");
 259                 printf("---------------------------------------------------\n");
 260                 pretty_print_string_list(&other_cmds, longest);
 261                 putchar('\n');
 262         }
 263 }
 264
 265 void list_common_cmds_help(void)
 266 {
 267         int i, longest = 0;
 268
 269         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 270                 if (longest < strlen(common_cmds[i].name))
 271                         longest = strlen(common_cmds[i].name);
 272         }
 273
 274         puts("The most commonly used git commands are:");
 275         for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 276                 printf("   %s   ", common_cmds[i].name);
 277                 mput_char(' ', longest - strlen(common_cmds[i].name));
 278                 puts(common_cmds[i].help);
 279         }
 280 }
 281
 282 static const char *cmd_to_page(const char *git_cmd)
 283 {
 284         if (!git_cmd)
 285                 return "git";
 286         else if (!prefixcmp(git_cmd, "git"))
 287                 return git_cmd;
 288         else {
 289                 int page_len = strlen(git_cmd) + 4;
 290                 char *p = xmalloc(page_len + 1);
 291                 strcpy(p, "git-");
 292                 strcpy(p + 4, git_cmd);
 293                 p[page_len] = 0;
 294                 return p;
 295         }
 296 }
 297
 298 static void setup_man_path(void)
 299 {
 300         struct strbuf new_path;
 301         const char *old_path = getenv("MANPATH");
 302
 303         strbuf_init(&new_path, 0);
 304
 305         /* We should always put ':' after our path. If there is no
 306          * old_path, the ':' at the end will let 'man' to try
 307          * system-wide paths after ours to find the manual page. If
 308          * there is old_path, we need ':' as delimiter. */
 309         strbuf_addstr(&new_path, GIT_MAN_PATH);
 310         strbuf_addch(&new_path, ':');
 311         if (old_path)
 312                 strbuf_addstr(&new_path, old_path);
 313
 314         setenv("MANPATH", new_path.buf, 1);
 315
 316         strbuf_release(&new_path);
 317 }
 318
 319 static void show_man_page(const char *git_cmd)
 320 {
 321         const char *page = cmd_to_page(git_cmd);
 322         setup_man_path();
 323         execlp("man", "man", page, NULL);
 324 }
 325
 326 static void show_info_page(const char *git_cmd)
 327 {
 328         const char *page = cmd_to_page(git_cmd);
 329         setenv("INFOPATH", GIT_INFO_PATH, 1);
 330         execlp("info", "info", "gitman", page, NULL);
 331 }
 332
 333 static void get_html_page_path(struct strbuf *page_path, const char *page)
 334 {
 335         struct stat st;
 336
 337         /* Check that we have a git documentation directory. */
 338         if (stat(GIT_HTML_PATH "/git.html", &st) || !S_ISREG(st.st_mode))
 339                 die("'%s': not a documentation directory.", GIT_HTML_PATH);
 340
 341         strbuf_init(page_path, 0);
 342         strbuf_addf(page_path, GIT_HTML_PATH "/%s.html", page);
 343 }
 344
 345 static void show_html_page(const char *git_cmd)
 346 {
 347         const char *page = cmd_to_page(git_cmd);
 348         struct strbuf page_path; /* it leaks but we exec bellow */
 349
 350         get_html_page_path(&page_path, page);
 351
 352         execl_git_cmd("web--browse", "-c", "help.browser", page_path.buf, NULL);
 353 }
 354
 355 void help_unknown_cmd(const char *cmd)
 356 {
 357         fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 358         exit(1);
 359 }
 360
 361 int cmd_version(int argc, const char **argv, const char *prefix)
 362 {
 363         printf("git version %s\n", git_version_string);
 364         return 0;
 365 }
 366
 367 int cmd_help(int argc, const char **argv, const char *prefix)
 368 {
 369         const char *help_cmd = argv[1];
 370
 371         if (argc < 2) {
 372                 printf("usage: %s\n\n", git_usage_string);
 373                 list_common_cmds_help();
 374                 exit(0);
 375         }
 376
 377         if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
 378                 printf("usage: %s\n\n", git_usage_string);
 379                 list_commands();
 380         }
 381
 382         else if (!strcmp(help_cmd, "--web") || !strcmp(help_cmd, "-w")) {
 383                 show_html_page(argc > 2 ? argv[2] : NULL);
 384         }
 385
 386         else if (!strcmp(help_cmd, "--info") || !strcmp(help_cmd, "-i")) {
 387                 show_info_page(argc > 2 ? argv[2] : NULL);
 388         }
 389
 390         else if (!strcmp(help_cmd, "--man") || !strcmp(help_cmd, "-m")) {
 391                 show_man_page(argc > 2 ? argv[2] : NULL);
 392         }
 393
 394         else {
 395                 int nongit;
 396
 397                 setup_git_directory_gently(&nongit);
 398                 git_config(git_help_config);
 399                 if (help_default_format)
 400                         parse_help_format(help_default_format);
 401
 402                 switch (help_format) {
 403                 case man_format:
 404                         show_man_page(help_cmd);
 405                         break;
 406                 case info_format:
 407                         show_info_page(help_cmd);
 408                         break;
 409                 case web_format:
 410                         show_html_page(help_cmd);
 411                         break;
 412                 }
 413         }
 414
 415         return 0;
 416 }