1 /* mini man implementation for busybox
2 * Copyright (C) 2008 Denys Vlasenko <vda.linux@googlemail.com>
3 * Licensed under GPLv2, see file LICENSE in this source tree.
6 //usage:#define man_trivial_usage
7 //usage: "[-aw] [MANPAGE]..."
8 //usage:#define man_full_usage "\n\n"
9 //usage: "Format and display manual page\n"
10 //usage: "\n -a Display all pages"
11 //usage: "\n -w Show page locations"
17 OPT_w
= 2, /* print path */
20 /* This is what I see on my desktop system being executed:
26 gunzip -c '/usr/man/man1/bzip2.1.gz'
29 ) | gtbl | nroff -Tlatin1 -mandoc | less
33 static int show_manpage(const char *pager
, char *man_filename
, int man
, int level
);
35 static int run_pipe(const char *pager
, char *man_filename
, int man
, int level
)
39 /* Prevent man page link loops */
43 if (access(man_filename
, R_OK
) != 0)
46 if (option_mask32
& OPT_w
) {
51 if (man
) { /* man page, not cat page */
52 /* Is this a link to another manpage? */
53 /* The link has the following on the first line: */
54 /* ".so another_man_page" */
61 * man1/genhostid.1.gz: 203 bytes - smallest real manpage
62 * man2/path_resolution.2.gz: 114 bytes - largest link
64 xstat(man_filename
, &sb
);
65 if (sb
.st_size
> 300) /* err on the safe side */
66 goto ordinary_manpage
;
68 line
= xmalloc_open_zipped_read_close(man_filename
, NULL
);
69 if (!line
|| strncmp(line
, ".so ", 4) != 0) {
71 goto ordinary_manpage
;
73 /* Example: man2/path_resolution.2.gz contains
74 * ".so man7/path_resolution.7\n<junk>"
76 *strchrnul(line
, '\n') = '\0';
77 linkname
= skip_whitespace(&line
[4]);
79 /* If link has no slashes, we just replace man page name.
80 * If link has slashes (however many), we go back *once*.
81 * ".so zzz/ggg/page.3" does NOT go back two levels. */
82 p
= strrchr(man_filename
, '/');
84 goto ordinary_manpage
;
86 if (strchr(linkname
, '/')) {
87 p
= strrchr(man_filename
, '/');
89 goto ordinary_manpage
;
93 /* Links do not have .gz extensions, even if manpage
95 man_filename
= xasprintf("%s/%s", man_filename
, linkname
);
97 /* Note: we leak "new" man_filename string as well... */
98 if (show_manpage(pager
, man_filename
, man
, level
+ 1))
100 /* else: show the link, it's better than nothing */
105 open_zipped(man_filename
, /*fail_if_not_compressed:*/ 0); /* guaranteed to use fd 0 (STDIN_FILENO) */
106 /* "2>&1" is added so that nroff errors are shown in pager too.
107 * Otherwise it may show just empty screen */
109 /* replaced -Tlatin1 with -Tascii for non-UTF8 displays */
110 man
? "gtbl | nroff -Tascii -mandoc 2>&1 | %s"
118 /* man_filename is of the form "/dir/dir/dir/name.s" */
119 static int show_manpage(const char *pager
, char *man_filename
, int man
, int level
)
121 #if SEAMLESS_COMPRESSION
122 /* We leak this allocation... */
123 char *filename_with_zext
= xasprintf("%s.lzma", man_filename
);
124 char *ext
= strrchr(filename_with_zext
, '.') + 1;
127 #if ENABLE_FEATURE_SEAMLESS_LZMA
128 if (run_pipe(pager
, filename_with_zext
, man
, level
))
131 #if ENABLE_FEATURE_SEAMLESS_XZ
133 if (run_pipe(pager
, filename_with_zext
, man
, level
))
136 #if ENABLE_FEATURE_SEAMLESS_BZ2
138 if (run_pipe(pager
, filename_with_zext
, man
, level
))
141 #if ENABLE_FEATURE_SEAMLESS_GZ
143 if (run_pipe(pager
, filename_with_zext
, man
, level
))
147 return run_pipe(pager
, man_filename
, man
, level
);
150 static char **add_MANPATH(char **man_path_list
, int *count_mp
, char *path
)
152 if (path
) while (*path
) {
156 next_path
= strchr(path
, ':');
158 if (next_path
== path
) /* "::"? */
162 /* Do we already have path? */
163 path_element
= man_path_list
;
164 if (path_element
) while (*path_element
) {
165 if (strcmp(*path_element
, path
) == 0)
169 man_path_list
= xrealloc_vector(man_path_list
, 4, *count_mp
);
170 man_path_list
[*count_mp
] = xstrdup(path
);
172 /* man_path_list is NULL terminated */
173 /* man_path_list[*count_mp] = NULL; - xrealloc_vector did it */
177 /* "path" may be a result of getenv(), be nice and don't mangle it */
180 path
= next_path
+ 1;
182 return man_path_list
;
185 int man_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
186 int man_main(int argc UNUSED_PARAM
, char **argv
)
189 const char *pager
= ENABLE_LESS
? "less" : "more";
191 char *cur_path
, *cur_sect
;
192 char **man_path_list
;
198 opt_complementary
= "-1"; /* at least one argument */
199 opt
= getopt32(argv
, "+aw");
202 sec_list
= xstrdup("0p:1:1p:2:3:3p:4:5:6:7:8:9");
205 man_path_list
= add_MANPATH(NULL
, &count_mp
,
206 getenv("MANDATORY_MANPATH"+10) /* "MANPATH" */
208 if (!man_path_list
) {
209 /* default, may be overridden by /etc/man.conf */
210 man_path_list
= xzalloc(2 * sizeof(man_path_list
[0]));
211 man_path_list
[0] = (char*)"/usr/man";
213 * Thus, man.conf will overwrite man_path_list[0]
214 * if a path is defined there.
218 /* Parse man.conf[ig] or man_db.conf */
219 /* man version 1.6f uses man.config */
220 /* man-db implementation of man uses man_db.conf */
221 parser
= config_open2("/etc/man.config", fopen_for_read
);
223 parser
= config_open2("/etc/man.conf", fopen_for_read
);
225 parser
= config_open2("/etc/man_db.conf", fopen_for_read
);
227 while (config_read(parser
, token
, 2, 0, "# \t", PARSE_NORMAL
)) {
230 if (strcmp("DEFINE", token
[0]) == 0) {
231 if (strncmp("pager", token
[1], 5) == 0) {
232 pager
= xstrdup(skip_whitespace(token
[1]) + 5);
235 if (strcmp("MANDATORY_MANPATH"+10, token
[0]) == 0 /* "MANPATH"? */
236 || strcmp("MANDATORY_MANPATH", token
[0]) == 0
238 man_path_list
= add_MANPATH(man_path_list
, &count_mp
, token
[1]);
240 if (strcmp("MANSECT", token
[0]) == 0) {
242 sec_list
= xstrdup(token
[1]);
245 config_close(parser
);
248 /* environment overrides setting from man.config */
249 char *env_pager
= getenv("MANPAGER");
251 env_pager
= getenv("PAGER");
257 do { /* for each argv[] */
261 if (strchr(*argv
, '/')) {
262 found
= show_manpage(pager
, *argv
, /*man:*/ 1, 0);
265 while ((cur_path
= man_path_list
[cur_mp
++]) != NULL
) {
266 /* for each MANPATH */
268 do { /* for each section */
269 char *next_sect
= strchrnul(cur_sect
, ':');
270 int sect_len
= next_sect
- cur_sect
;
274 /* Search for cat, then man page */
275 while (cat0man1
< 2) {
277 man_filename
= xasprintf("%s/%s%.*s/%s.%.*s",
279 "cat\0man" + (cat0man1
* 4),
283 found_here
= show_manpage(pager
, man_filename
, cat0man1
, 0);
285 cat0man1
+= found_here
+ 1;
289 if (found
&& !(opt
& OPT_a
))
291 cur_sect
= next_sect
;
292 while (*cur_sect
== ':')
298 bb_error_msg("no manual entry for '%s'", *argv
);