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 "help.h"
  13
  14static struct man_viewer_list {
  15        struct man_viewer_list *next;
  16        char name[FLEX_ARRAY];
  17} *man_viewer_list;
  18
  19static struct man_viewer_info_list {
  20        struct man_viewer_info_list *next;
  21        const char *info;
  22        char name[FLEX_ARRAY];
  23} *man_viewer_info_list;
  24
  25enum help_format {
  26        HELP_FORMAT_MAN,
  27        HELP_FORMAT_INFO,
  28        HELP_FORMAT_WEB,
  29};
  30
  31static int show_all = 0;
  32static enum help_format help_format = HELP_FORMAT_MAN;
  33static struct option builtin_help_options[] = {
  34        OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
  35        OPT_SET_INT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
  36        OPT_SET_INT('w', "web", &help_format, "show manual in web browser",
  37                        HELP_FORMAT_WEB),
  38        OPT_SET_INT('i', "info", &help_format, "show info page",
  39                        HELP_FORMAT_INFO),
  40        OPT_END(),
  41};
  42
  43static const char * const builtin_help_usage[] = {
  44        "git help [--all] [--man|--web|--info] [command]",
  45        NULL
  46};
  47
  48static enum help_format parse_help_format(const char *format)
  49{
  50        if (!strcmp(format, "man"))
  51                return HELP_FORMAT_MAN;
  52        if (!strcmp(format, "info"))
  53                return HELP_FORMAT_INFO;
  54        if (!strcmp(format, "web") || !strcmp(format, "html"))
  55                return HELP_FORMAT_WEB;
  56        die("unrecognized help format '%s'", format);
  57}
  58
  59static const char *get_man_viewer_info(const char *name)
  60{
  61        struct man_viewer_info_list *viewer;
  62
  63        for (viewer = man_viewer_info_list; viewer; viewer = viewer->next)
  64        {
  65                if (!strcasecmp(name, viewer->name))
  66                        return viewer->info;
  67        }
  68        return NULL;
  69}
  70
  71static int check_emacsclient_version(void)
  72{
  73        struct strbuf buffer = STRBUF_INIT;
  74        struct child_process ec_process;
  75        const char *argv_ec[] = { "emacsclient", "--version", NULL };
  76        int version;
  77
  78        /* emacsclient prints its version number on stderr */
  79        memset(&ec_process, 0, sizeof(ec_process));
  80        ec_process.argv = argv_ec;
  81        ec_process.err = -1;
  82        ec_process.stdout_to_stderr = 1;
  83        if (start_command(&ec_process)) {
  84                fprintf(stderr, "Failed to start emacsclient.\n");
  85                return -1;
  86        }
  87        strbuf_read(&buffer, ec_process.err, 20);
  88        close(ec_process.err);
  89
  90        /*
  91         * Don't bother checking return value, because "emacsclient --version"
  92         * seems to always exits with code 1.
  93         */
  94        finish_command(&ec_process);
  95
  96        if (prefixcmp(buffer.buf, "emacsclient")) {
  97                fprintf(stderr, "Failed to parse emacsclient version.\n");
  98                strbuf_release(&buffer);
  99                return -1;
 100        }
 101
 102        strbuf_remove(&buffer, 0, strlen("emacsclient"));
 103        version = atoi(buffer.buf);
 104
 105        if (version < 22) {
 106                fprintf(stderr,
 107                        "emacsclient version '%d' too old (< 22).\n",
 108                        version);
 109                strbuf_release(&buffer);
 110                return -1;
 111        }
 112
 113        strbuf_release(&buffer);
 114        return 0;
 115}
 116
 117static void exec_woman_emacs(const char* path, const char *page)
 118{
 119        if (!check_emacsclient_version()) {
 120                /* This works only with emacsclient version >= 22. */
 121                struct strbuf man_page = STRBUF_INIT;
 122
 123                if (!path)
 124                        path = "emacsclient";
 125                strbuf_addf(&man_page, "(woman \"%s\")", page);
 126                execlp(path, "emacsclient", "-e", man_page.buf, NULL);
 127                warning("failed to exec '%s': %s", path, strerror(errno));
 128        }
 129}
 130
 131static void exec_man_konqueror(const char* path, const char *page)
 132{
 133        const char *display = getenv("DISPLAY");
 134        if (display && *display) {
 135                struct strbuf man_page = STRBUF_INIT;
 136                const char *filename = "kfmclient";
 137
 138                /* It's simpler to launch konqueror using kfmclient. */
 139                if (path) {
 140                        const char *file = strrchr(path, '/');
 141                        if (file && !strcmp(file + 1, "konqueror")) {
 142                                char *new = xstrdup(path);
 143                                char *dest = strrchr(new, '/');
 144
 145                                /* strlen("konqueror") == strlen("kfmclient") */
 146                                strcpy(dest + 1, "kfmclient");
 147                                path = new;
 148                        }
 149                        if (file)
 150                                filename = file;
 151                } else
 152                        path = "kfmclient";
 153                strbuf_addf(&man_page, "man:%s(1)", page);
 154                execlp(path, filename, "newTab", man_page.buf, NULL);
 155                warning("failed to exec '%s': %s", path, strerror(errno));
 156        }
 157}
 158
 159static void exec_man_man(const char* path, const char *page)
 160{
 161        if (!path)
 162                path = "man";
 163        execlp(path, "man", page, NULL);
 164        warning("failed to exec '%s': %s", path, strerror(errno));
 165}
 166
 167static void exec_man_cmd(const char *cmd, const char *page)
 168{
 169        struct strbuf shell_cmd = STRBUF_INIT;
 170        strbuf_addf(&shell_cmd, "%s %s", cmd, page);
 171        execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
 172        warning("failed to exec '%s': %s", cmd, strerror(errno));
 173}
 174
 175static void add_man_viewer(const char *name)
 176{
 177        struct man_viewer_list **p = &man_viewer_list;
 178        size_t len = strlen(name);
 179
 180        while (*p)
 181                p = &((*p)->next);
 182        *p = xcalloc(1, (sizeof(**p) + len + 1));
 183        strncpy((*p)->name, name, len);
 184}
 185
 186static int supported_man_viewer(const char *name, size_t len)
 187{
 188        return (!strncasecmp("man", name, len) ||
 189                !strncasecmp("woman", name, len) ||
 190                !strncasecmp("konqueror", name, len));
 191}
 192
 193static void do_add_man_viewer_info(const char *name,
 194                                   size_t len,
 195                                   const char *value)
 196{
 197        struct man_viewer_info_list *new = xcalloc(1, sizeof(*new) + len + 1);
 198
 199        strncpy(new->name, name, len);
 200        new->info = xstrdup(value);
 201        new->next = man_viewer_info_list;
 202        man_viewer_info_list = new;
 203}
 204
 205static int add_man_viewer_path(const char *name,
 206                               size_t len,
 207                               const char *value)
 208{
 209        if (supported_man_viewer(name, len))
 210                do_add_man_viewer_info(name, len, value);
 211        else
 212                warning("'%s': path for unsupported man viewer.\n"
 213                        "Please consider using 'man.<tool>.cmd' instead.",
 214                        name);
 215
 216        return 0;
 217}
 218
 219static int add_man_viewer_cmd(const char *name,
 220                              size_t len,
 221                              const char *value)
 222{
 223        if (supported_man_viewer(name, len))
 224                warning("'%s': cmd for supported man viewer.\n"
 225                        "Please consider using 'man.<tool>.path' instead.",
 226                        name);
 227        else
 228                do_add_man_viewer_info(name, len, value);
 229
 230        return 0;
 231}
 232
 233static int add_man_viewer_info(const char *var, const char *value)
 234{
 235        const char *name = var + 4;
 236        const char *subkey = strrchr(name, '.');
 237
 238        if (!subkey)
 239                return error("Config with no key for man viewer: %s", name);
 240
 241        if (!strcmp(subkey, ".path")) {
 242                if (!value)
 243                        return config_error_nonbool(var);
 244                return add_man_viewer_path(name, subkey - name, value);
 245        }
 246        if (!strcmp(subkey, ".cmd")) {
 247                if (!value)
 248                        return config_error_nonbool(var);
 249                return add_man_viewer_cmd(name, subkey - name, value);
 250        }
 251
 252        warning("'%s': unsupported man viewer sub key.", subkey);
 253        return 0;
 254}
 255
 256static int git_help_config(const char *var, const char *value, void *cb)
 257{
 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, NULL);
 380}
 381
 382static void get_html_page_path(struct strbuf *page_path, const char *page)
 383{
 384        struct stat st;
 385        const char *html_path = system_path(GIT_HTML_PATH);
 386
 387        /* Check that we have a git documentation directory. */
 388        if (stat(mkpath("%s/git.html", html_path), &st)
 389            || !S_ISREG(st.st_mode))
 390                die("'%s': not a documentation directory.", html_path);
 391
 392        strbuf_init(page_path, 0);
 393        strbuf_addf(page_path, "%s/%s.html", html_path, page);
 394}
 395
 396/*
 397 * If open_html is not defined in a platform-specific way (see for
 398 * example compat/mingw.h), we use the script web--browse to display
 399 * HTML.
 400 */
 401#ifndef open_html
 402void open_html(const char *path)
 403{
 404        execl_git_cmd("web--browse", "-c", "help.browser", path, NULL);
 405}
 406#endif
 407
 408static void show_html_page(const char *git_cmd)
 409{
 410        const char *page = cmd_to_page(git_cmd);
 411        struct strbuf page_path; /* it leaks but we exec bellow */
 412
 413        get_html_page_path(&page_path, page);
 414
 415        open_html(page_path.buf);
 416}
 417
 418int cmd_help(int argc, const char **argv, const char *prefix)
 419{
 420        int nongit;
 421        const char *alias;
 422        load_command_list("git-", &main_cmds, &other_cmds);
 423
 424        setup_git_directory_gently(&nongit);
 425        git_config(git_help_config, NULL);
 426
 427        argc = parse_options(argc, argv, builtin_help_options,
 428                        builtin_help_usage, 0);
 429
 430        if (show_all) {
 431                printf("usage: %s\n\n", git_usage_string);
 432                list_commands("git commands", &main_cmds, &other_cmds);
 433                printf("%s\n", git_more_info_string);
 434                return 0;
 435        }
 436
 437        if (!argv[0]) {
 438                printf("usage: %s\n\n", git_usage_string);
 439                list_common_cmds_help();
 440                printf("\n%s\n", git_more_info_string);
 441                return 0;
 442        }
 443
 444        alias = alias_lookup(argv[0]);
 445        if (alias && !is_git_command(argv[0])) {
 446                printf("`git %s' is aliased to `%s'\n", argv[0], alias);
 447                return 0;
 448        }
 449
 450        switch (help_format) {
 451        case HELP_FORMAT_MAN:
 452                show_man_page(argv[0]);
 453                break;
 454        case HELP_FORMAT_INFO:
 455                show_info_page(argv[0]);
 456                break;
 457        case HELP_FORMAT_WEB:
 458                show_html_page(argv[0]);
 459                break;
 460        }
 461
 462        return 0;
 463}