blob: 9d58ef4fc3f000df1074f96b71bf06665dd80b4b
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. |
4 | */ |
5 | |
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" |
12 | |
13 | #include "libbb.h" |
14 | |
15 | enum { |
16 | OPT_a = 1, /* all */ |
17 | OPT_w = 2, /* print path */ |
18 | }; |
19 | |
20 | /* This is what I see on my desktop system being executed: |
21 | |
22 | ( |
23 | echo ".ll 12.4i" |
24 | echo ".nr LL 12.4i" |
25 | echo ".pl 1100i" |
26 | gunzip -c '/usr/man/man1/bzip2.1.gz' |
27 | echo ".\\\"" |
28 | echo ".pl \n(nlu+10" |
29 | ) | gtbl | nroff -Tlatin1 -mandoc | less |
30 | |
31 | */ |
32 | |
33 | static int show_manpage(const char *pager, char *man_filename, int man, int level); |
34 | |
35 | static int run_pipe(const char *pager, char *man_filename, int man, int level) |
36 | { |
37 | char *cmd; |
38 | |
39 | /* Prevent man page link loops */ |
40 | if (level > 10) |
41 | return 0; |
42 | |
43 | if (access(man_filename, R_OK) != 0) |
44 | return 0; |
45 | |
46 | if (option_mask32 & OPT_w) { |
47 | puts(man_filename); |
48 | return 1; |
49 | } |
50 | |
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" */ |
55 | |
56 | struct stat sb; |
57 | char *line; |
58 | char *linkname, *p; |
59 | |
60 | /* On my system: |
61 | * man1/genhostid.1.gz: 203 bytes - smallest real manpage |
62 | * man2/path_resolution.2.gz: 114 bytes - largest link |
63 | */ |
64 | xstat(man_filename, &sb); |
65 | if (sb.st_size > 300) /* err on the safe side */ |
66 | goto ordinary_manpage; |
67 | |
68 | line = xmalloc_open_zipped_read_close(man_filename, NULL); |
69 | if (!line || strncmp(line, ".so ", 4) != 0) { |
70 | free(line); |
71 | goto ordinary_manpage; |
72 | } |
73 | /* Example: man2/path_resolution.2.gz contains |
74 | * ".so man7/path_resolution.7\n<junk>" |
75 | */ |
76 | *strchrnul(line, '\n') = '\0'; |
77 | linkname = skip_whitespace(&line[4]); |
78 | |
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, '/'); |
83 | if (!p) |
84 | goto ordinary_manpage; |
85 | *p = '\0'; |
86 | if (strchr(linkname, '/')) { |
87 | p = strrchr(man_filename, '/'); |
88 | if (!p) |
89 | goto ordinary_manpage; |
90 | *p = '\0'; |
91 | } |
92 | |
93 | /* Links do not have .gz extensions, even if manpage |
94 | * is compressed */ |
95 | man_filename = xasprintf("%s/%s", man_filename, linkname); |
96 | free(line); |
97 | /* Note: we leak "new" man_filename string as well... */ |
98 | if (show_manpage(pager, man_filename, man, level + 1)) |
99 | return 1; |
100 | /* else: show the link, it's better than nothing */ |
101 | } |
102 | |
103 | ordinary_manpage: |
104 | close(STDIN_FILENO); |
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 */ |
108 | cmd = xasprintf( |
109 | man ? "gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s" |
110 | : "%s", |
111 | pager); |
112 | system(cmd); |
113 | free(cmd); |
114 | return 1; |
115 | } |
116 | |
117 | /* man_filename is of the form "/dir/dir/dir/name.s" */ |
118 | static int show_manpage(const char *pager, char *man_filename, int man, int level) |
119 | { |
120 | #if SEAMLESS_COMPRESSION |
121 | /* We leak this allocation... */ |
122 | char *filename_with_zext = xasprintf("%s.lzma", man_filename); |
123 | char *ext = strrchr(filename_with_zext, '.') + 1; |
124 | #endif |
125 | |
126 | #if ENABLE_FEATURE_SEAMLESS_LZMA |
127 | if (run_pipe(pager, filename_with_zext, man, level)) |
128 | return 1; |
129 | #endif |
130 | #if ENABLE_FEATURE_SEAMLESS_XZ |
131 | strcpy(ext, "xz"); |
132 | if (run_pipe(pager, filename_with_zext, man, level)) |
133 | return 1; |
134 | #endif |
135 | #if ENABLE_FEATURE_SEAMLESS_BZ2 |
136 | strcpy(ext, "bz2"); |
137 | if (run_pipe(pager, filename_with_zext, man, level)) |
138 | return 1; |
139 | #endif |
140 | #if ENABLE_FEATURE_SEAMLESS_GZ |
141 | strcpy(ext, "gz"); |
142 | if (run_pipe(pager, filename_with_zext, man, level)) |
143 | return 1; |
144 | #endif |
145 | |
146 | return run_pipe(pager, man_filename, man, level); |
147 | } |
148 | |
149 | int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
150 | int man_main(int argc UNUSED_PARAM, char **argv) |
151 | { |
152 | parser_t *parser; |
153 | const char *pager; |
154 | char **man_path_list; |
155 | char *sec_list; |
156 | char *cur_path, *cur_sect; |
157 | int count_mp, cur_mp; |
158 | int opt, not_found; |
159 | char *token[2]; |
160 | |
161 | opt_complementary = "-1"; /* at least one argument */ |
162 | opt = getopt32(argv, "+aw"); |
163 | argv += optind; |
164 | |
165 | sec_list = xstrdup("0p:1:1p:2:3:3p:4:5:6:7:8:9"); |
166 | /* Last valid man_path_list[] is [0x10] */ |
167 | count_mp = 0; |
168 | man_path_list = xzalloc(0x11 * sizeof(man_path_list[0])); |
169 | man_path_list[0] = getenv("MANPATH"); |
170 | if (!man_path_list[0]) /* default, may be overridden by /etc/man.conf */ |
171 | man_path_list[0] = (char*)"/usr/man"; |
172 | else |
173 | count_mp++; |
174 | pager = getenv("MANPAGER"); |
175 | if (!pager) { |
176 | pager = getenv("PAGER"); |
177 | if (!pager) |
178 | pager = "more"; |
179 | } |
180 | |
181 | /* Parse man.conf[ig] or man_db.conf */ |
182 | /* man version 1.6f uses man.config */ |
183 | /* man-db implementation of man uses man_db.conf */ |
184 | parser = config_open2("/etc/man.config", fopen_for_read); |
185 | if (!parser) |
186 | parser = config_open2("/etc/man.conf", fopen_for_read); |
187 | if (!parser) |
188 | parser = config_open2("/etc/man_db.conf", fopen_for_read); |
189 | |
190 | while (config_read(parser, token, 2, 0, "# \t", PARSE_NORMAL)) { |
191 | if (!token[1]) |
192 | continue; |
193 | if (strcmp("MANDATORY_MANPATH"+10, token[0]) == 0 /* "MANPATH"? */ |
194 | || strcmp("MANDATORY_MANPATH", token[0]) == 0 |
195 | ) { |
196 | char *path = token[1]; |
197 | while (*path) { |
198 | char *next_path; |
199 | char **path_element; |
200 | |
201 | next_path = strchr(path, ':'); |
202 | if (next_path) { |
203 | *next_path = '\0'; |
204 | if (next_path++ == path) /* "::"? */ |
205 | goto next; |
206 | } |
207 | /* Do we already have path? */ |
208 | path_element = man_path_list; |
209 | while (*path_element) { |
210 | if (strcmp(*path_element, path) == 0) |
211 | goto skip; |
212 | path_element++; |
213 | } |
214 | man_path_list = xrealloc_vector(man_path_list, 4, count_mp); |
215 | man_path_list[count_mp] = xstrdup(path); |
216 | count_mp++; |
217 | /* man_path_list is NULL terminated */ |
218 | /*man_path_list[count_mp] = NULL; - xrealloc_vector did it */ |
219 | skip: |
220 | if (!next_path) |
221 | break; |
222 | next: |
223 | path = next_path; |
224 | } |
225 | } |
226 | if (strcmp("MANSECT", token[0]) == 0) { |
227 | free(sec_list); |
228 | sec_list = xstrdup(token[1]); |
229 | } |
230 | } |
231 | config_close(parser); |
232 | |
233 | not_found = 0; |
234 | do { /* for each argv[] */ |
235 | int found = 0; |
236 | cur_mp = 0; |
237 | |
238 | if (strchr(*argv, '/')) { |
239 | found = show_manpage(pager, *argv, /*man:*/ 1, 0); |
240 | goto check_found; |
241 | } |
242 | while ((cur_path = man_path_list[cur_mp++]) != NULL) { |
243 | /* for each MANPATH */ |
244 | cur_sect = sec_list; |
245 | do { /* for each section */ |
246 | char *next_sect = strchrnul(cur_sect, ':'); |
247 | int sect_len = next_sect - cur_sect; |
248 | char *man_filename; |
249 | int cat0man1 = 0; |
250 | |
251 | /* Search for cat, then man page */ |
252 | while (cat0man1 < 2) { |
253 | int found_here; |
254 | man_filename = xasprintf("%s/%s%.*s/%s.%.*s", |
255 | cur_path, |
256 | "cat\0man" + (cat0man1 * 4), |
257 | sect_len, cur_sect, |
258 | *argv, |
259 | sect_len, cur_sect); |
260 | found_here = show_manpage(pager, man_filename, cat0man1, 0); |
261 | found |= found_here; |
262 | cat0man1 += found_here + 1; |
263 | free(man_filename); |
264 | } |
265 | |
266 | if (found && !(opt & OPT_a)) |
267 | goto next_arg; |
268 | cur_sect = next_sect; |
269 | while (*cur_sect == ':') |
270 | cur_sect++; |
271 | } while (*cur_sect); |
272 | } |
273 | check_found: |
274 | if (!found) { |
275 | bb_error_msg("no manual entry for '%s'", *argv); |
276 | not_found = 1; |
277 | } |
278 | next_arg: |
279 | argv++; |
280 | } while (*argv); |
281 | |
282 | return not_found; |
283 | } |
284 |