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