Contents of /tags/mkinitrd-6_3_5/busybox/miscutils/man.c
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
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Sat Jan 29 14:06:54 2011 UTC (13 years, 8 months ago) by niro
File MIME type: text/plain
File size: 7040 byte(s)
tagged 'mkinitrd-6_3_5'
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 tarball for details. |
4 | */ |
5 | |
6 | #include "libbb.h" |
7 | |
8 | enum { |
9 | OPT_a = 1, /* all */ |
10 | OPT_w = 2, /* print path */ |
11 | }; |
12 | |
13 | /* This is what I see on my desktop system being executed: |
14 | |
15 | ( |
16 | echo ".ll 12.4i" |
17 | echo ".nr LL 12.4i" |
18 | echo ".pl 1100i" |
19 | gunzip -c '/usr/man/man1/bzip2.1.gz' |
20 | echo ".\\\"" |
21 | echo ".pl \n(nlu+10" |
22 | ) | gtbl | nroff -Tlatin1 -mandoc | less |
23 | |
24 | */ |
25 | |
26 | #if ENABLE_FEATURE_SEAMLESS_LZMA |
27 | #define Z_SUFFIX ".lzma" |
28 | #elif ENABLE_FEATURE_SEAMLESS_BZ2 |
29 | #define Z_SUFFIX ".bz2" |
30 | #elif ENABLE_FEATURE_SEAMLESS_GZ |
31 | #define Z_SUFFIX ".gz" |
32 | #else |
33 | #define Z_SUFFIX "" |
34 | #endif |
35 | |
36 | static int show_manpage(const char *pager, char *man_filename, int man, int level); |
37 | |
38 | static int run_pipe(const char *pager, char *man_filename, int man, int level) |
39 | { |
40 | char *cmd; |
41 | |
42 | /* Prevent man page link loops */ |
43 | if (level > 10) |
44 | return 0; |
45 | |
46 | if (access(man_filename, R_OK) != 0) |
47 | return 0; |
48 | |
49 | if (option_mask32 & OPT_w) { |
50 | puts(man_filename); |
51 | return 1; |
52 | } |
53 | |
54 | if (man) { /* man page, not cat page */ |
55 | /* Is this a link to another manpage? */ |
56 | /* The link has the following on the first line: */ |
57 | /* ".so another_man_page" */ |
58 | |
59 | struct stat sb; |
60 | char *line; |
61 | char *linkname, *p; |
62 | |
63 | /* On my system: |
64 | * man1/genhostid.1.gz: 203 bytes - smallest real manpage |
65 | * man2/path_resolution.2.gz: 114 bytes - largest link |
66 | */ |
67 | xstat(man_filename, &sb); |
68 | if (sb.st_size > 300) /* err on the safe side */ |
69 | goto ordinary_manpage; |
70 | |
71 | line = xmalloc_open_zipped_read_close(man_filename, NULL); |
72 | if (!line || strncmp(line, ".so ", 4) != 0) { |
73 | free(line); |
74 | goto ordinary_manpage; |
75 | } |
76 | /* Example: man2/path_resolution.2.gz contains |
77 | * ".so man7/path_resolution.7\n<junk>" |
78 | */ |
79 | *strchrnul(line, '\n') = '\0'; |
80 | linkname = skip_whitespace(&line[4]); |
81 | |
82 | /* If link has no slashes, we just replace man page name. |
83 | * If link has slashes (however many), we go back *once*. |
84 | * ".so zzz/ggg/page.3" does NOT go back two levels. */ |
85 | p = strrchr(man_filename, '/'); |
86 | if (!p) |
87 | goto ordinary_manpage; |
88 | *p = '\0'; |
89 | if (strchr(linkname, '/')) { |
90 | p = strrchr(man_filename, '/'); |
91 | if (!p) |
92 | goto ordinary_manpage; |
93 | *p = '\0'; |
94 | } |
95 | |
96 | /* Links do not have .gz extensions, even if manpage |
97 | * is compressed */ |
98 | man_filename = xasprintf("%s/%s" Z_SUFFIX, man_filename, linkname); |
99 | free(line); |
100 | /* Note: we leak "new" man_filename string as well... */ |
101 | if (show_manpage(pager, man_filename, man, level + 1)) |
102 | return 1; |
103 | /* else: show the link, it's better than nothing */ |
104 | } |
105 | |
106 | ordinary_manpage: |
107 | close(STDIN_FILENO); |
108 | open_zipped(man_filename); /* guaranteed to use fd 0 (STDIN_FILENO) */ |
109 | /* "2>&1" is added so that nroff errors are shown in pager too. |
110 | * Otherwise it may show just empty screen */ |
111 | cmd = xasprintf( |
112 | man ? "gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s" |
113 | : "%s", |
114 | pager); |
115 | system(cmd); |
116 | free(cmd); |
117 | return 1; |
118 | } |
119 | |
120 | /* man_filename is of the form "/dir/dir/dir/name.s" Z_SUFFIX */ |
121 | static int show_manpage(const char *pager, char *man_filename, int man, int level) |
122 | { |
123 | #if ENABLE_FEATURE_SEAMLESS_LZMA |
124 | if (run_pipe(pager, man_filename, man, level)) |
125 | return 1; |
126 | #endif |
127 | |
128 | #if ENABLE_FEATURE_SEAMLESS_BZ2 |
129 | #if ENABLE_FEATURE_SEAMLESS_LZMA |
130 | strcpy(strrchr(man_filename, '.') + 1, "bz2"); |
131 | #endif |
132 | if (run_pipe(pager, man_filename, man, level)) |
133 | return 1; |
134 | #endif |
135 | |
136 | #if ENABLE_FEATURE_SEAMLESS_GZ |
137 | #if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2 |
138 | strcpy(strrchr(man_filename, '.') + 1, "gz"); |
139 | #endif |
140 | if (run_pipe(pager, man_filename, man, level)) |
141 | return 1; |
142 | #endif |
143 | |
144 | #if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2 || ENABLE_FEATURE_SEAMLESS_GZ |
145 | *strrchr(man_filename, '.') = '\0'; |
146 | #endif |
147 | if (run_pipe(pager, man_filename, man, level)) |
148 | return 1; |
149 | |
150 | return 0; |
151 | } |
152 | |
153 | int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
154 | int man_main(int argc UNUSED_PARAM, char **argv) |
155 | { |
156 | parser_t *parser; |
157 | const char *pager; |
158 | char **man_path_list; |
159 | char *sec_list; |
160 | char *cur_path, *cur_sect; |
161 | int count_mp, cur_mp; |
162 | int opt, not_found; |
163 | char *token[2]; |
164 | |
165 | opt_complementary = "-1"; /* at least one argument */ |
166 | opt = getopt32(argv, "+aw"); |
167 | argv += optind; |
168 | |
169 | sec_list = xstrdup("1:2:3:4:5:6:7:8:9"); |
170 | /* Last valid man_path_list[] is [0x10] */ |
171 | count_mp = 0; |
172 | man_path_list = xzalloc(0x11 * sizeof(man_path_list[0])); |
173 | man_path_list[0] = getenv("MANPATH"); |
174 | if (!man_path_list[0]) /* default, may be overridden by /etc/man.conf */ |
175 | man_path_list[0] = (char*)"/usr/man"; |
176 | else |
177 | count_mp++; |
178 | pager = getenv("MANPAGER"); |
179 | if (!pager) { |
180 | pager = getenv("PAGER"); |
181 | if (!pager) |
182 | pager = "more"; |
183 | } |
184 | |
185 | /* Parse man.conf[ig] */ |
186 | /* man version 1.6f uses man.config */ |
187 | parser = config_open2("/etc/man.config", fopen_for_read); |
188 | if (!parser) |
189 | parser = config_open2("/etc/man.conf", fopen_for_read); |
190 | |
191 | while (config_read(parser, token, 2, 0, "# \t", PARSE_NORMAL)) { |
192 | if (!token[1]) |
193 | continue; |
194 | if (strcmp("MANPATH", token[0]) == 0) { |
195 | char *path = token[1]; |
196 | while (*path) { |
197 | char *next_path; |
198 | char **path_element; |
199 | |
200 | next_path = strchr(path, ':'); |
201 | if (next_path) { |
202 | *next_path = '\0'; |
203 | if (next_path++ == path) /* "::"? */ |
204 | goto next; |
205 | } |
206 | /* Do we already have path? */ |
207 | path_element = man_path_list; |
208 | while (*path_element) { |
209 | if (strcmp(*path_element, path) == 0) |
210 | goto skip; |
211 | path_element++; |
212 | } |
213 | man_path_list = xrealloc_vector(man_path_list, 4, count_mp); |
214 | man_path_list[count_mp] = xstrdup(path); |
215 | count_mp++; |
216 | /* man_path_list is NULL terminated */ |
217 | /*man_path_list[count_mp] = NULL; - xrealloc_vector did it */ |
218 | skip: |
219 | if (!next_path) |
220 | break; |
221 | next: |
222 | path = next_path; |
223 | } |
224 | } |
225 | if (strcmp("MANSECT", token[0]) == 0) { |
226 | free(sec_list); |
227 | sec_list = xstrdup(token[1]); |
228 | } |
229 | } |
230 | config_close(parser); |
231 | |
232 | not_found = 0; |
233 | do { /* for each argv[] */ |
234 | int found = 0; |
235 | cur_mp = 0; |
236 | |
237 | if (strchr(*argv, '/')) { |
238 | found = show_manpage(pager, *argv, /*man:*/ 1, 0); |
239 | goto check_found; |
240 | } |
241 | while ((cur_path = man_path_list[cur_mp++]) != NULL) { |
242 | /* for each MANPATH */ |
243 | cur_sect = sec_list; |
244 | do { /* for each section */ |
245 | char *next_sect = strchrnul(cur_sect, ':'); |
246 | int sect_len = next_sect - cur_sect; |
247 | char *man_filename; |
248 | int cat0man1 = 0; |
249 | |
250 | /* Search for cat, then man page */ |
251 | while (cat0man1 < 2) { |
252 | int found_here; |
253 | man_filename = xasprintf("%s/%s%.*s/%s.%.*s" Z_SUFFIX, |
254 | cur_path, |
255 | "cat\0man" + (cat0man1 * 4), |
256 | sect_len, cur_sect, |
257 | *argv, |
258 | sect_len, cur_sect); |
259 | found_here = show_manpage(pager, man_filename, cat0man1, 0); |
260 | found |= found_here; |
261 | cat0man1 += found_here + 1; |
262 | free(man_filename); |
263 | } |
264 | |
265 | if (found && !(opt & OPT_a)) |
266 | goto next_arg; |
267 | cur_sect = next_sect; |
268 | while (*cur_sect == ':') |
269 | cur_sect++; |
270 | } while (*cur_sect); |
271 | } |
272 | check_found: |
273 | if (!found) { |
274 | bb_error_msg("no manual entry for '%s'", *argv); |
275 | not_found = 1; |
276 | } |
277 | next_arg: |
278 | argv++; |
279 | } while (*argv); |
280 | |
281 | return not_found; |
282 | } |