From 540baf646a526a68aeb83a3c6da706a2f2a1aeb2 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 5 Aug 2008 13:16:18 +0000 Subject: man: add handling of "man links", by Ivana Varekova function old new delta run_pipe 102 354 +252 show_manpage - 126 +126 man_main 705 615 -90 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/1 up/down: 378/-90) Total: 288 bytes --- miscutils/man.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 62 insertions(+), 11 deletions(-) (limited to 'miscutils') diff --git a/miscutils/man.c b/miscutils/man.c index f499fef62..91b995cf4 100644 --- a/miscutils/man.c +++ b/miscutils/man.c @@ -27,10 +27,19 @@ echo ".pl \n(nlu+10" #define STR_catNULmanNUL "cat\0man" #define STR_cat "cat\0man" -static int run_pipe(const char *unpacker, const char *pager, char *man_filename, int man) +//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; @@ -39,6 +48,53 @@ static int run_pipe(const char *unpacker, const char *pager, char *man_filename, return 1; } + if (man) { /* man page, not cat page */ + /* Test whether the man page is not a link to another one. */ + /* 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" + */ + *strchrnul(line, '\n') = '\0'; + linkname = p = skip_whitespace(&line[4]); + while (1) { + char *newname_slash, *oldname_slash; + + oldname_slash = strrchr(man_filename, '/'); + if (!oldname_slash) + goto ordinary_manpage; + *oldname_slash = '\0'; + newname_slash = strchr(p, '/'); + if (!newname_slash) + break; + p = newname_slash + 1; + } + 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( @@ -51,22 +107,22 @@ static int run_pipe(const char *unpacker, const char *pager, char *man_filename, } /* man_filename is of the form "/dir/dir/dir/name.s.bz2" */ -static int show_manpage(const char *pager, char *man_filename, int man) +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)) + 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)) + 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)) + if (run_pipe(STR_cat, pager, man_filename, man, level)) return 1; return 0; @@ -121,11 +177,6 @@ int man_main(int argc UNUSED_PARAM, char **argv) } config_close(parser); -// TODO: my man3/getpwuid.3.gz contains just one line: -// .so man3/getpwnam.3 -// (and I _dont_ have man3/getpwnam.3, I have man3/getpwnam.3.gz) -// need to support this... - not_found = 0; do { /* for each argv[] */ int found = 0; @@ -151,7 +202,7 @@ int man_main(int argc UNUSED_PARAM, char **argv) sect_len, cur_sect, *argv, sect_len, cur_sect); - found_here = show_manpage(pager, man_filename, cat0man1); + found_here = show_manpage(pager, man_filename, cat0man1, 0); found |= found_here; cat0man1 += found_here + 1; free(man_filename); -- cgit v1.2.3