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|
/* 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 being 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
*/
/* Trick gcc to reuse "cat" string. */
#define STR_catNULmanNUL "cat\0man"
#define STR_cat "cat\0man"
//TODO: make gz/bz2 support conditional on FEATURE_SEAMLESS_GZ/BZ2,
// add SEAMLESS_LZMA support
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 man, int level)
{
char *cmd;
/* Prevent man page link loops */
if (level > 10)
return 0;
if (access(man_filename, R_OK) != 0)
return 0;
if (option_mask32 & OPT_w) {
puts(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" ".bz2", 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:
/* "2>&1" is added so that nroff errors are shown in pager too.
* Otherwise it may show just empty screen */
cmd = xasprintf(
man ? "%s '%s' 2>&1 | gtbl | nroff -Tlatin1 -mandoc 2>&1 | %s"
: "%s '%s' 2>&1 | %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 man, int level)
{
int len;
if (run_pipe("bunzip2 -c", pager, man_filename, 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, man, level))
return 1;
man_filename[len - 3] = '\0'; /* ".gz" -> "" */
if (run_pipe(STR_cat, pager, man_filename, man, level))
return 1;
return 0;
}
int man_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int man_main(int argc UNUSED_PARAM, char **argv)
{
parser_t *parser;
const char *pager;
char **man_path_list;
char *sec_list;
char *cur_path, *cur_sect;
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");
/* 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])
count_mp++;
pager = getenv("MANPAGER");
if (!pager) {
pager = getenv("PAGER");
if (!pager)
pager = "more";
}
/* Parse man.conf */
parser = config_open("/etc/man.conf");
while (config_read(parser, token, 2, 0, "# \t", PARSE_NORMAL)) {
if (!token[1])
continue;
if (strcmp("MANPATH", token[0]) == 0) {
man_path_list = xrealloc_vector(man_path_list, 4, count_mp);
man_path_list[count_mp] = xstrdup(token[1]);
count_mp++;
/* man_path_list is NULL terminated */
/*man_path_list[count_mp] = NULL; - xrealloc_vector did it */
}
if (strcmp("MANSECT", token[0]) == 0) {
free(sec_list);
sec_list = xstrdup(token[1]);
}
}
config_close(parser);
not_found = 0;
do { /* for each argv[] */
int found = 0;
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;
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, 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);
cur_path = next_path;
while (*cur_path == ':')
cur_path++;
} while (*cur_path);
}
if (!found) {
bb_error_msg("no manual entry for '%s'", *argv);
not_found = 1;
}
next_arg:
argv++;
} while (*argv);
return not_found;
}
|
