aboutsummaryrefslogtreecommitdiff
path: root/miscutils/man.c
blob: bf13ab527e805b659a937e989b414aee86dcb709 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/* 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.
 */

#include "libbb.h"

enum {
	OPT_a = 1, /* all */
	OPT_w = 2, /* print path */
};

/* This is what I see on my desktop system deing 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 run_pipe(const char *unpacker, const char *pager, char *man_filename)
{
	char *cmd;

	if (access(man_filename, R_OK) != 0)
		return 0;

	if (option_mask32 & OPT_w) {
		puts(man_filename);
		return 1;
	}

	cmd = xasprintf("%s '%s' | gtbl | nroff -Tlatin1 -mandoc | %s",
			unpacker, man_filename, 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 len;

	if (run_pipe("bunzip2 -c", pager, man_filename))
		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))
		return 1;

	man_filename[len - 3] = '\0'; /* ".gz" -> "" */
	if (run_pipe("cat", pager, man_filename))
		return 1;

	return 0;
}

int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int man_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
	FILE *cf;
	const char *pager;
	char **man_path_list;
	char *sec_list;
	char *cur_path, *cur_sect;
	char *line, *value;
	int count_mp, alloc_mp, cur_mp;
	int opt;

	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");
	alloc_mp = 10;
	man_path_list = xmalloc(10 * sizeof(man_path_list[0])); 
	count_mp = 0;
	man_path_list[0] = xstrdup(getenv("MANPATH"));
	if (man_path_list[0])
		count_mp++;
	pager = getenv("MANPAGER");
	if (!pager) {
		pager = getenv("PAGER");
		if (!pager)
			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++;
					if (alloc_mp == count_mp) {
						alloc_mp += 10;
						man_path_list = xrealloc(man_path_list, alloc_mp * sizeof(man_path_list[0]));
					}
					/* thus man_path_list is always NULL terminated */
				}
				if (strcmp("MANSECT", line) == 0) {
					free(sec_list);
					sec_list = xstrdup(value);
				}
			}
			free(line);
		}
		fclose(cf);
	}

	do { /* for each argv[] */
		cur_mp = 0;
		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 = xasprintf("%.*s/man%.*s/%s.%.*s" ".bz2",
								path_len, cur_path,
			        				sect_len, cur_sect,
			        				*argv,
								sect_len, cur_sect);
					int found = show_manpage(pager, man_filename);
					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);
		}
 next_arg:
		argv++;
	} while (*argv);

	return EXIT_SUCCESS;
}