Bump to version 1.22.1
[platform/upstream/busybox.git] / miscutils / man.c
index 509ae96..d3e832b 100644 (file)
@@ -1,8 +1,15 @@
 /* mini man implementation for busybox
  * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * 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 {
@@ -23,14 +30,16 @@ echo ".pl \n(nlu+10"
 
 */
 
-/* Trick gcc to reuse "cat" string. */
-#define STR_catNULmanNUL "cat\0man"
-#define STR_cat          "cat\0man"
+static int show_manpage(const char *pager, char *man_filename, int man, int level);
 
-static int run_pipe(const char *unpacker, const char *pager, char *man_filename, int cat)
+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;
 
@@ -39,60 +48,128 @@ static int run_pipe(const char *unpacker, const char *pager, char *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); /* 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(cat ? "%s '%s' | %s"
-                       : "%s '%s' | gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s",
-                       unpacker, man_filename, pager);
+       cmd = xasprintf(
+               man ? "gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s"
+                   : "%s",
+               pager);
        system(cmd);
        free(cmd);
        return 1;
 }
 
-/* man_filename is of the form "/dir/dir/dir/name.s.bz2" */
-static int show_manpage(const char *pager, char *man_filename, int cat)
+/* 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)
 {
-       int len;
+#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 (run_pipe("bunzip2 -c", pager, man_filename, cat))
+#if ENABLE_FEATURE_SEAMLESS_LZMA
+       if (run_pipe(pager, filename_with_zext, man, level))
                return 1;
-
-       len = strlen(man_filename) - 1;
-
-       man_filename[len] = '\0'; /* ".bz2" -> ".gz" */
-       man_filename[len - 2] = 'g';
-       if (run_pipe("gunzip -c", pager, man_filename, cat))
+#endif
+#if ENABLE_FEATURE_SEAMLESS_XZ
+       strcpy(ext, "xz");
+       if (run_pipe(pager, filename_with_zext, man, level))
                return 1;
-
-       man_filename[len - 3] = '\0'; /* ".gz" -> "" */
-       if (run_pipe(STR_cat, pager, man_filename, cat))
+#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 0;
+       return run_pipe(pager, man_filename, man, level);
 }
 
 int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int man_main(int argc ATTRIBUTE_UNUSED, char **argv)
+int man_main(int argc UNUSED_PARAM, char **argv)
 {
-       FILE *cf;
+       parser_t *parser;
        const char *pager;
        char **man_path_list;
        char *sec_list;
        char *cur_path, *cur_sect;
-       char *line, *value;
        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("1:2:3:4:5:6:7:8:9");
+       sec_list = xstrdup("0p:1:1p:2:3:3p:4:5:6:7:8:9");
        /* Last valid man_path_list[] is [0x10] */
-       man_path_list = xzalloc(0x11 * sizeof(man_path_list[0]));
        count_mp = 0;
-       man_path_list[0] = xstrdup(getenv("MANPATH"));
-       if (man_path_list[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++;
        pager = getenv("MANPAGER");
        if (!pager) {
@@ -101,84 +178,99 @@ int man_main(int argc ATTRIBUTE_UNUSED, char **argv)
                        pager = "more";
        }
 
-       /* Parse man.conf */
-       cf = fopen_or_warn("/etc/man.conf", "r");
-       if (cf) {
-               /* go through man configuration file and search relevant paths, sections */
-               while ((line = xmalloc_fgetline(cf)) != NULL) {
-                       trim(line); /* remove whitespace at the beginning/end */
-                       if (isspace(line[7])) {
-                               line[7] = '\0';
-                               value = skip_whitespace(&line[8]);
-                               *skip_non_whitespace(value) = '\0';
-                               if (strcmp("MANPATH", line) == 0) {
-                                       man_path_list[count_mp] = xstrdup(value);
-                                       count_mp++;
-                                       /* man_path_list is NULL terminated */
-                                       man_path_list[count_mp] = NULL;
-                                       if (!(count_mp & 0xf)) { /* 0x10, 0x20 etc */
-                                               /* so that last valid man_path_list[] is [count_mp + 0x10] */
-                                               man_path_list = xrealloc(man_path_list,
-                                                       (count_mp + 0x11) * sizeof(man_path_list[0]));
-                                       }
+       /* 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("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;
                                }
-                               if (strcmp("MANSECT", line) == 0) {
-                                       free(sec_list);
-                                       sec_list = xstrdup(value);
+                               /* 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;
                        }
-                       free(line);
                }
-               fclose(cf);
+               if (strcmp("MANSECT", token[0]) == 0) {
+                       free(sec_list);
+                       sec_list = xstrdup(token[1]);
+               }
        }
-
-// TODO: my man3/getpwuid.3.gz contains just one line:
-// .so man3/getpwnam.3
-// (and I _dont_ have man3/getpwnam.3, I have man3/getpwnam.3.gz)
-// need to support this...
+       config_close(parser);
 
        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 */
-                       do { /* for each MANPATH item */
-                               char *next_path = strchrnul(cur_path, ':');
-                               int path_len = next_path - cur_path;
-                               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" ".bz2",
-                                                               path_len, cur_path,
-                                                               STR_catNULmanNUL + cat0man1 * 4,
-                                                               sect_len, cur_sect,
-                                                               *argv,
-                                                               sect_len, cur_sect);
-                                               found_here = show_manpage(pager, man_filename, cat0man1);
-                                               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);
-                               cur_path = next_path;
-                               while (*cur_path == ':')
-                                       cur_path++;
-                       } while (*cur_path);
+                       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;