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