Andrew's git - gitweb.git/blob

   1/*
   2 * builtin-help.c
   3 *
   4 * Builtin help command
   5 */
   6#include "cache.h"
   7#include "builtin.h"
   8#include "exec_cmd.h"
   9#include "common-cmds.h"
  10#include "parse-options.h"
  11#include "run-command.h"
  12#include "column.h"
  13#include "help.h"
  14
  15static struct man_viewer_list {
  16        struct man_viewer_list *next;
  17        char name[FLEX_ARRAY];
  18} *man_viewer_list;
  19
  20static struct man_viewer_info_list {
  21        struct man_viewer_info_list *next;
  22        const char *info;
  23        char name[FLEX_ARRAY];
  24} *man_viewer_info_list;
  25
  26enum help_format {
  27        HELP_FORMAT_NONE,
  28        HELP_FORMAT_MAN,
  29        HELP_FORMAT_INFO,
  30        HELP_FORMAT_WEB
  31};
  32
  33static int show_all = 0;
  34static unsigned int colopts;
  35static enum help_format help_format = HELP_FORMAT_NONE;
  36static struct option builtin_help_options[] = {
  37        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  38        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  39        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  40                        HELP_FORMAT_WEB),
  41        OPT_SET_INT('i', "info", &help_format, "show info page",
  42                        HELP_FORMAT_INFO),
  43        OPT_END(),
  44};
  45
  46static const char * const builtin_help_usage[] = {
  47        "git help [--all] [--man|--web|--info] [command]",
  48        NULL
  49};
  50
  51static enum help_format parse_help_format(const char *format)
  52{
  53        if (!strcmp(format, "man"))
  54                return HELP_FORMAT_MAN;
  55        if (!strcmp(format, "info"))
  56                return HELP_FORMAT_INFO;
  57        if (!strcmp(format, "web") || !strcmp(format, "html"))
  58                return HELP_FORMAT_WEB;
  59        die("unrecognized help format '%s'", format);
  60}
  61
  62static const char *get_man_viewer_info(const char *name)
  63{
  64        struct man_viewer_info_list *viewer;
  65
  66        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  67        {
  68                if (!strcasecmp(name, viewer->name))
  69                        return viewer->info;
  70        }
  71        return NULL;
  72}
  73
  74static int check_emacsclient_version(void)
  75{
  76        struct strbuf buffer = STRBUF_INIT;
  77        struct child_process ec_process;
  78        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  79        int version;
  80
  81        /* emacsclient prints its version number on stderr */
  82        memset(&ec_process, 0, sizeof(ec_process));
  83        ec_process.argv = argv_ec;
  84        ec_process.err = -1;
  85        ec_process.stdout_to_stderr = 1;
  86        if (start_command(&ec_process))
  87                return error("Failed to start emacsclient.");
  88
  89        strbuf_read(&buffer, ec_process.err, 20);
  90        close(ec_process.err);
  91
  92        /*
  93         * Don't bother checking return value, because "emacsclient --version"
  94         * seems to always exits with code 1.
  95         */
  96        finish_command(&ec_process);
  97
  98        if (prefixcmp(buffer.buf, "emacsclient")) {
  99                strbuf_release(&buffer);
 100                return error("Failed to parse emacsclient version.");
 101        }
 102
 103        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 104        version = atoi(buffer.buf);
 105
 106        if (version < 22) {
 107                strbuf_release(&buffer);
 108                return error("emacsclient version '%d' too old (< 22).",
 109                        version);
 110        }
 111
 112        strbuf_release(&buffer);
 113        return 0;
 114}
 115
 116static void exec_woman_emacs(const char *path, const char *page)
 117{
 118        if (!check_emacsclient_version()) {
 119                /* This works only with emacsclient version >= 22. */
 120                struct strbuf man_page = STRBUF_INIT;
 121
 122                if (!path)
 123                        path = "emacsclient";
 124                strbuf_addf(&man_page, "(woman \"%s\")", page);
 125                execlp(path, "emacsclient", "-e", man_page.buf, (char *)NULL);
 126                warning("failed to exec '%s': %s", path, strerror(errno));
 127        }
 128}
 129
 130static void exec_man_konqueror(const char *path, const char *page)
 131{
 132        const char *display = getenv("DISPLAY");
 133        if (display && *display) {
 134                struct strbuf man_page = STRBUF_INIT;
 135                const char *filename = "kfmclient";
 136
 137                /* It's simpler to launch konqueror using kfmclient. */
 138                if (path) {
 139                        const char *file = strrchr(path, '/');
 140                        if (file && !strcmp(file + 1, "konqueror")) {
 141                                char *new = xstrdup(path);
 142                                char *dest = strrchr(new, '/');
 143
 144                                /* strlen("konqueror") == strlen("kfmclient") */
 145                                strcpy(dest + 1, "kfmclient");
 146                                path = new;
 147                        }
 148                        if (file)
 149                                filename = file;
 150                } else
 151                        path = "kfmclient";
 152                strbuf_addf(&man_page, "man:%s(1)", page);
 153                execlp(path, filename, "newTab", man_page.buf, (char *)NULL);
 154                warning("failed to exec '%s': %s", path, strerror(errno));
 155        }
 156}
 157
 158static void exec_man_man(const char *path, const char *page)
 159{
 160        if (!path)
 161                path = "man";
 162        execlp(path, "man", page, (char *)NULL);
 163        warning("failed to exec '%s': %s", path, strerror(errno));
 164}
 165
 166static void exec_man_cmd(const char *cmd, const char *page)
 167{
 168        struct strbuf shell_cmd = STRBUF_INIT;
 169        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 170        execl("/bin/sh", "sh", "-c", shell_cmd.buf, (char *)NULL);
 171        warning("failed to exec '%s': %s", cmd, strerror(errno));
 172}
 173
 174static void add_man_viewer(const char *name)
 175{
 176        struct man_viewer_list **p = &man_viewer_list;
 177        size_t len = strlen(name);
 178
 179        while (*p)
 180                p = &((*p)->next);
 181        *p = xcalloc(1, (sizeof(**p) + len + 1));
 182        strncpy((*p)->name, name, len);
 183}
 184
 185static int supported_man_viewer(const char *name, size_t len)
 186{
 187        return (!strncasecmp("man", name, len) ||
 188                !strncasecmp("woman", name, len) ||
 189                !strncasecmp("konqueror", name, len));
 190}
 191
 192static void do_add_man_viewer_info(const char *name,
 193                                   size_t len,
 194                                   const char *value)
 195{
 196        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 197
 198        strncpy(new->name, name, len);
 199        new->info = xstrdup(value);
 200        new->next = man_viewer_info_list;
 201        man_viewer_info_list = new;
 202}
 203
 204static int add_man_viewer_path(const char *name,
 205                               size_t len,
 206                               const char *value)
 207{
 208        if (supported_man_viewer(name, len))
 209                do_add_man_viewer_info(name, len, value);
 210        else
 211                warning("'%s': path for unsupported man viewer.\n"
 212                        "Please consider using 'man.<tool>.cmd' instead.",
 213                        name);
 214
 215        return 0;
 216}
 217
 218static int add_man_viewer_cmd(const char *name,
 219                              size_t len,
 220                              const char *value)
 221{
 222        if (supported_man_viewer(name, len))
 223                warning("'%s': cmd for supported man viewer.\n"
 224                        "Please consider using 'man.<tool>.path' instead.",
 225                        name);
 226        else
 227                do_add_man_viewer_info(name, len, value);
 228
 229        return 0;
 230}
 231
 232static int add_man_viewer_info(const char *var, const char *value)
 233{
 234        const char *name = var + 4;
 235        const char *subkey = strrchr(name, '.');
 236
 237        if (!subkey)
 238                return 0;
 239
 240        if (!strcmp(subkey, ".path")) {
 241                if (!value)
 242                        return config_error_nonbool(var);
 243                return add_man_viewer_path(name, subkey - name, value);
 244        }
 245        if (!strcmp(subkey, ".cmd")) {
 246                if (!value)
 247                        return config_error_nonbool(var);
 248                return add_man_viewer_cmd(name, subkey - name, value);
 249        }
 250
 251        return 0;
 252}
 253
 254static int git_help_config(const char *var, const char *value, void *cb)
 255{
 256        if (!prefixcmp(var, "column."))
 257                return git_column_config(var, value, "help", &colopts);
 258        if (!strcmp(var, "help.format")) {
 259                if (!value)
 260                        return config_error_nonbool(var);
 261                help_format = parse_help_format(value);
 262                return 0;
 263        }
 264        if (!strcmp(var, "man.viewer")) {
 265                if (!value)
 266                        return config_error_nonbool(var);
 267                add_man_viewer(value);
 268                return 0;
 269        }
 270        if (!prefixcmp(var, "man."))
 271                return add_man_viewer_info(var, value);
 272
 273        return git_default_config(var, value, cb);
 274}
 275
 276static struct cmdnames main_cmds, other_cmds;
 277
 278void list_common_cmds_help(void)
 279{
 280        int i, longest = 0;
 281
 282        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 283                if (longest < strlen(common_cmds[i].name))
 284                        longest = strlen(common_cmds[i].name);
 285        }
 286
 287        puts("The most commonly used git commands are:");
 288        for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 289                printf("   %s   ", common_cmds[i].name);
 290                mput_char(' ', longest - strlen(common_cmds[i].name));
 291                puts(common_cmds[i].help);
 292        }
 293}
 294
 295static int is_git_command(const char *s)
 296{
 297        return is_in_cmdlist(&main_cmds, s) ||
 298                is_in_cmdlist(&other_cmds, s);
 299}
 300
 301static const char *prepend(const char *prefix, const char *cmd)
 302{
 303        size_t pre_len = strlen(prefix);
 304        size_t cmd_len = strlen(cmd);
 305        char *p = xmalloc(pre_len + cmd_len + 1);
 306        memcpy(p, prefix, pre_len);
 307        strcpy(p + pre_len, cmd);
 308        return p;
 309}
 310
 311static const char *cmd_to_page(const char *git_cmd)
 312{
 313        if (!git_cmd)
 314                return "git";
 315        else if (!prefixcmp(git_cmd, "git"))
 316                return git_cmd;
 317        else if (is_git_command(git_cmd))
 318                return prepend("git-", git_cmd);
 319        else
 320                return prepend("git", git_cmd);
 321}
 322
 323static void setup_man_path(void)
 324{
 325        struct strbuf new_path = STRBUF_INIT;
 326        const char *old_path = getenv("MANPATH");
 327
 328        /* We should always put ':' after our path. If there is no
 329         * old_path, the ':' at the end will let 'man' to try
 330         * system-wide paths after ours to find the manual page. If
 331         * there is old_path, we need ':' as delimiter. */
 332        strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
 333        strbuf_addch(&new_path, ':');
 334        if (old_path)
 335                strbuf_addstr(&new_path, old_path);
 336
 337        setenv("MANPATH", new_path.buf, 1);
 338
 339        strbuf_release(&new_path);
 340}
 341
 342static void exec_viewer(const char *name, const char *page)
 343{
 344        const char *info = get_man_viewer_info(name);
 345
 346        if (!strcasecmp(name, "man"))
 347                exec_man_man(info, page);
 348        else if (!strcasecmp(name, "woman"))
 349                exec_woman_emacs(info, page);
 350        else if (!strcasecmp(name, "konqueror"))
 351                exec_man_konqueror(info, page);
 352        else if (info)
 353                exec_man_cmd(info, page);
 354        else
 355                warning("'%s': unknown man viewer.", name);
 356}
 357
 358static void show_man_page(const char *git_cmd)
 359{
 360        struct man_viewer_list *viewer;
 361        const char *page = cmd_to_page(git_cmd);
 362        const char *fallback = getenv("GIT_MAN_VIEWER");
 363
 364        setup_man_path();
 365        for (viewer = man_viewer_list; viewer; viewer = viewer->next)
 366        {
 367                exec_viewer(viewer->name, page); /* will return when unable */
 368        }
 369        if (fallback)
 370                exec_viewer(fallback, page);
 371        exec_viewer("man", page);
 372        die("no man viewer handled the request");
 373}
 374
 375static void show_info_page(const char *git_cmd)
 376{
 377        const char *page = cmd_to_page(git_cmd);
 378        setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 379        execlp("info", "info", "gitman", page, (char *)NULL);
 380        die("no info viewer handled the request");
 381}
 382
 383static void get_html_page_path(struct strbuf *page_path, const char *page)
 384{
 385        struct stat st;
 386        const char *html_path = system_path(GIT_HTML_PATH);
 387
 388        /* Check that we have a git documentation directory. */
 389        if (stat(mkpath("%s/git.html", html_path), &st)
 390            || !S_ISREG(st.st_mode))
 391                die("'%s': not a documentation directory.", html_path);
 392
 393        strbuf_init(page_path, 0);
 394        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 395}
 396
 397/*
 398 * If open_html is not defined in a platform-specific way (see for
 399 * example compat/mingw.h), we use the script web--browse to display
 400 * HTML.
 401 */
 402#ifndef open_html
 403static void open_html(const char *path)
 404{
 405        execl_git_cmd("web--browse", "-c", "help.browser", path, (char *)NULL);
 406}
 407#endif
 408
 409static void show_html_page(const char *git_cmd)
 410{
 411        const char *page = cmd_to_page(git_cmd);
 412        struct strbuf page_path; /* it leaks but we exec bellow */
 413
 414        get_html_page_path(&page_path, page);
 415
 416        open_html(page_path.buf);
 417}
 418
 419int cmd_help(int argc, const char **argv, const char *prefix)
 420{
 421        int nongit;
 422        const char *alias;
 423        enum help_format parsed_help_format;
 424        load_command_list("git-", &main_cmds, &other_cmds);
 425
 426        argc = parse_options(argc, argv, prefix, builtin_help_options,
 427                        builtin_help_usage, 0);
 428        parsed_help_format = help_format;
 429
 430        if (show_all) {
 431                git_config(git_help_config, NULL);
 432                printf("usage: %s\n\n", git_usage_string);
 433                list_commands("git commands", colopts, &main_cmds, &other_cmds);
 434                printf("%s\n", git_more_info_string);
 435                return 0;
 436        }
 437
 438        if (!argv[0]) {
 439                printf("usage: %s\n\n", git_usage_string);
 440                list_common_cmds_help();
 441                printf("\n%s\n", git_more_info_string);
 442                return 0;
 443        }
 444
 445        setup_git_directory_gently(&nongit);
 446        git_config(git_help_config, NULL);
 447
 448        if (parsed_help_format != HELP_FORMAT_NONE)
 449                help_format = parsed_help_format;
 450
 451        alias = alias_lookup(argv[0]);
 452        if (alias && !is_git_command(argv[0])) {
 453                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 454                return 0;
 455        }
 456
 457        switch (help_format) {
 458        case HELP_FORMAT_NONE:
 459        case HELP_FORMAT_MAN:
 460                show_man_page(argv[0]);
 461                break;
 462        case HELP_FORMAT_INFO:
 463                show_info_page(argv[0]);
 464                break;
 465        case HELP_FORMAT_WEB:
 466                show_html_page(argv[0]);
 467                break;
 468        }
 469
 470        return 0;
 471}