/* mini man implementation for busybox * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com> * Licensed under GPLv2, see file LICENSE in this source tree. */ //usage:#define man_trivial_usage //usage: "[-aw] [MANPAGE]..." //usage:#define man_full_usage "\n\n" //usage: "Format and display manual page\n" //usage: "\n -a Display all pages" //usage: "\n -w Show page locations" #include "libbb.h" enum { OPT_a = 1, /* all */ OPT_w = 2, /* print path */ }; /* This is what I see on my desktop system being executed: ( echo ".ll 12.4i" echo ".nr LL 12.4i" echo ".pl 1100i" gunzip -c '/usr/man/man1/bzip2.1.gz' echo ".\\\"" echo ".pl \n(nlu+10" ) | gtbl | nroff -Tlatin1 -mandoc | less */ static int show_manpage(const char *pager, char *man_filename, int man, int level); static int run_pipe(const char *pager, char *man_filename, int man, int level) { char *cmd; /* Prevent man page link loops */ if (level > 10) return 0; if (access(man_filename, R_OK) != 0) return 0; if (option_mask32 & OPT_w) { puts(man_filename); return 1; } if (man) { /* man page, not cat page */ /* Is this a link to another manpage? */ /* The link has the following on the first line: */ /* ".so another_man_page" */ struct stat sb; char *line; char *linkname, *p; /* On my system: * man1/genhostid.1.gz: 203 bytes - smallest real manpage * man2/path_resolution.2.gz: 114 bytes - largest link */ xstat(man_filename, &sb); if (sb.st_size > 300) /* err on the safe side */ goto ordinary_manpage; line = xmalloc_open_zipped_read_close(man_filename, NULL); if (!line || strncmp(line, ".so ", 4) != 0) { free(line); goto ordinary_manpage; } /* Example: man2/path_resolution.2.gz contains * ".so man7/path_resolution.7\n<junk>" */ *strchrnul(line, '\n') = '\0'; linkname = skip_whitespace(&line[4]); /* If link has no slashes, we just replace man page name. * If link has slashes (however many), we go back *once*. * ".so zzz/ggg/page.3" does NOT go back two levels. */ p = strrchr(man_filename, '/'); if (!p) goto ordinary_manpage; *p = '\0'; if (strchr(linkname, '/')) { p = strrchr(man_filename, '/'); if (!p) goto ordinary_manpage; *p = '\0'; } /* Links do not have .gz extensions, even if manpage * is compressed */ man_filename = xasprintf("%s/%s", man_filename, linkname); free(line); /* Note: we leak "new" man_filename string as well... */ if (show_manpage(pager, man_filename, man, level + 1)) return 1; /* else: show the link, it's better than nothing */ } ordinary_manpage: close(STDIN_FILENO); open_zipped(man_filename, /*fail_if_not_compressed:*/ 0); /* guaranteed to use fd 0 (STDIN_FILENO) */ /* "2>&1" is added so that nroff errors are shown in pager too. * Otherwise it may show just empty screen */ cmd = xasprintf( /* replaced -Tlatin1 with -Tascii for non-UTF8 displays */ man ? "gtbl | nroff -Tascii -mandoc 2>&1 | %s" : "%s", pager); system(cmd); free(cmd); return 1; } /* man_filename is of the form "/dir/dir/dir/name.s" */ static int show_manpage(const char *pager, char *man_filename, int man, int level) { #if SEAMLESS_COMPRESSION /* We leak this allocation... */ char *filename_with_zext = xasprintf("%s.lzma", man_filename); char *ext = strrchr(filename_with_zext, '.') + 1; #endif #if ENABLE_FEATURE_SEAMLESS_LZMA if (run_pipe(pager, filename_with_zext, man, level)) return 1; #endif #if ENABLE_FEATURE_SEAMLESS_XZ strcpy(ext, "xz"); if (run_pipe(pager, filename_with_zext, man, level)) return 1; #endif #if ENABLE_FEATURE_SEAMLESS_BZ2 strcpy(ext, "bz2"); if (run_pipe(pager, filename_with_zext, man, level)) return 1; #endif #if ENABLE_FEATURE_SEAMLESS_GZ strcpy(ext, "gz"); if (run_pipe(pager, filename_with_zext, man, level)) return 1; #endif return run_pipe(pager, man_filename, man, level); } int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int man_main(int argc UNUSED_PARAM, char **argv) { parser_t *parser; const char *pager = ENABLE_LESS ? "less" : "more"; char **man_path_list; char *sec_list; char *cur_path, *cur_sect; int count_mp, cur_mp; int opt, not_found; char *token[2]; opt_complementary = "-1"; /* at least one argument */ opt = getopt32(argv, "+aw"); argv += optind; sec_list = xstrdup("0p:1:1p:2:3:3p:4:5:6:7:8:9"); /* Last valid man_path_list[] is [0x10] */ count_mp = 0; man_path_list = xzalloc(0x11 * sizeof(man_path_list[0])); man_path_list[0] = getenv("MANPATH"); if (!man_path_list[0]) /* default, may be overridden by /etc/man.conf */ man_path_list[0] = (char*)"/usr/man"; else count_mp++; /* Parse man.conf[ig] or man_db.conf */ /* man version 1.6f uses man.config */ /* man-db implementation of man uses man_db.conf */ parser = config_open2("/etc/man.config", fopen_for_read); if (!parser) parser = config_open2("/etc/man.conf", fopen_for_read); if (!parser) parser = config_open2("/etc/man_db.conf", fopen_for_read); while (config_read(parser, token, 2, 0, "# \t", PARSE_NORMAL)) { if (!token[1]) continue; if (strcmp("DEFINE", token[0]) == 0) { if (strncmp("pager", token[1], 5) == 0) { pager = xstrdup(skip_whitespace(token[1]) + 5); } } else if (strcmp("MANDATORY_MANPATH"+10, token[0]) == 0 /* "MANPATH"? */ || strcmp("MANDATORY_MANPATH", token[0]) == 0 ) { char *path = token[1]; while (*path) { char *next_path; char **path_element; next_path = strchr(path, ':'); if (next_path) { *next_path = '\0'; if (next_path++ == path) /* "::"? */ goto next; } /* Do we already have path? */ path_element = man_path_list; while (*path_element) { if (strcmp(*path_element, path) == 0) goto skip; path_element++; } man_path_list = xrealloc_vector(man_path_list, 4, count_mp); man_path_list[count_mp] = xstrdup(path); count_mp++; /* man_path_list is NULL terminated */ /*man_path_list[count_mp] = NULL; - xrealloc_vector did it */ skip: if (!next_path) break; next: path = next_path; } } if (strcmp("MANSECT", token[0]) == 0) { free(sec_list); sec_list = xstrdup(token[1]); } } config_close(parser); { /* environment overrides setting from man.config */ char *env_pager = getenv("MANPAGER"); if (!env_pager) env_pager = getenv("PAGER"); if (env_pager) pager = env_pager; } not_found = 0; do { /* for each argv[] */ int found = 0; cur_mp = 0; if (strchr(*argv, '/')) { found = show_manpage(pager, *argv, /*man:*/ 1, 0); goto check_found; } while ((cur_path = man_path_list[cur_mp++]) != NULL) { /* for each MANPATH */ cur_sect = sec_list; do { /* for each section */ char *next_sect = strchrnul(cur_sect, ':'); int sect_len = next_sect - cur_sect; char *man_filename; int cat0man1 = 0; /* Search for cat, then man page */ while (cat0man1 < 2) { int found_here; man_filename = xasprintf("%s/%s%.*s/%s.%.*s", cur_path, "cat\0man" + (cat0man1 * 4), sect_len, cur_sect, *argv, sect_len, cur_sect); found_here = show_manpage(pager, man_filename, cat0man1, 0); found |= found_here; cat0man1 += found_here + 1; free(man_filename); } if (found && !(opt & OPT_a)) goto next_arg; cur_sect = next_sect; while (*cur_sect == ':') cur_sect++; } while (*cur_sect); } check_found: if (!found) { bb_error_msg("no manual entry for '%s'", *argv); not_found = 1; } next_arg: argv++; } while (*argv); return not_found; }