link: new applet
coreutils grew itself a tiny simplistic alternative to ln: Usage: link FILE LINK Create hard LINK to FILE function old new delta link_main - 75 +75 packed_usage 31114 31131 +17 applet_names 2564 2569 +5 applet_main 1480 1484 +4 applet_install_loc 185 186 +1 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 4/0 up/down: 102/0) Total: 102 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
parent
7dd906a388
commit
06f20bf675
@ -127,8 +127,9 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
|
||||
if (hard_link) {
|
||||
res = link(hard_link, dst_name);
|
||||
if (res != 0 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
|
||||
/* shared message */
|
||||
bb_perror_msg("can't create %slink "
|
||||
"from %s to %s", "hard",
|
||||
"%s to %s", "hard",
|
||||
dst_name,
|
||||
hard_link);
|
||||
}
|
||||
@ -181,8 +182,9 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
|
||||
if (res != 0
|
||||
&& !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)
|
||||
) {
|
||||
/* shared message */
|
||||
bb_perror_msg("can't create %slink "
|
||||
"from %s to %s", "sym",
|
||||
"%s to %s", "sym",
|
||||
dst_name,
|
||||
file_header->link_target);
|
||||
}
|
||||
|
41
coreutils/link.c
Normal file
41
coreutils/link.c
Normal file
@ -0,0 +1,41 @@
|
||||
/*
|
||||
* link implementation for busybox
|
||||
*
|
||||
* Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
|
||||
*
|
||||
* Licensed under GPLv2, see file LICENSE in this source tree.
|
||||
*/
|
||||
//config:config LINK
|
||||
//config: bool "link"
|
||||
//config: default y
|
||||
//config: help
|
||||
//config: link creates hard links between files.
|
||||
|
||||
//applet:IF_LINK(APPLET_NOFORK(link, link, BB_DIR_BIN, BB_SUID_DROP, link))
|
||||
|
||||
//kbuild:lib-$(CONFIG_LINK) += link.o
|
||||
|
||||
//usage:#define link_trivial_usage
|
||||
//usage: "FILE LINK"
|
||||
//usage:#define link_full_usage "\n\n"
|
||||
//usage: "Create hard LINK to FILE"
|
||||
|
||||
#include "libbb.h"
|
||||
|
||||
/* This is a NOFORK applet. Be very careful! */
|
||||
|
||||
int link_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int link_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
opt_complementary = "=2"; /* exactly 2 params */
|
||||
getopt32(argv, "");
|
||||
argv += optind;
|
||||
if (link(argv[0], argv[1]) != 0) {
|
||||
/* shared message */
|
||||
bb_perror_msg_and_die("can't create %slink "
|
||||
"%s to %s", "hard",
|
||||
argv[1], argv[0]
|
||||
);
|
||||
}
|
||||
return EXIT_SUCCESS;
|
||||
}
|
@ -33,6 +33,7 @@ roughly are:
|
||||
* do not expect shared global variables/buffers to be in their
|
||||
"initialized" state. Examples: xfunc_error_retval can be != 1,
|
||||
bb_common_bufsiz1 can be scribbled over, ...
|
||||
(although usually xfunc_error_retval's state is not a problem).
|
||||
* do not expect that stdio wasn't used before. Calling set[v]buf()
|
||||
can be disastrous.
|
||||
* ...
|
||||
@ -81,18 +82,37 @@ are probably not worth the effort.
|
||||
Any NOFORK applet is also a NOEXEC applet.
|
||||
|
||||
|
||||
Calling NOFORK applets
|
||||
|
||||
API to call NOFORK applets is two functions:
|
||||
|
||||
run_nofork_applet(appno, argv)
|
||||
spawn_and_wait(argv) // only if FEATURE_PREFER_APPLETS=y
|
||||
|
||||
First one is directly used by shells if FEATURE_SH_NOFORK=y.
|
||||
Second one is used by many applets, but main users are xargs and find.
|
||||
It itself calls run_nofork_applet(), if argv[0] turned out to be a name
|
||||
of a NOFORK applet.
|
||||
|
||||
run_nofork_applet() saves/inits/restores option parsing, xfunc_error_retval,
|
||||
applet_name. Thus, for example, caller does not need to worry about
|
||||
option_mask32 getting trashed.
|
||||
|
||||
|
||||
Relevant CONFIG options
|
||||
|
||||
FEATURE_PREFER_APPLETS
|
||||
BB_EXECVP(cmd, argv) will try to exec /proc/self/exe
|
||||
if command's name matches some applet name
|
||||
applet tables will contain NOFORK/NOEXEC bits
|
||||
if command's name matches some applet name;
|
||||
spawn_and_wait(argv) will do NOFORK/NOEXEC tricks
|
||||
|
||||
FEATURE_SH_STANDALONE (needs FEATURE_PREFER_APPLETS=y)
|
||||
shells will try to exec /proc/self/exe if command's name matches
|
||||
some applet name
|
||||
shells will do NOEXEC trick on NOEXEC applets
|
||||
//TODO: the above two things probably should have separate options?
|
||||
|
||||
FEATURE_SH_NOFORK (needs FEATURE_PREFER_APPLETS=y)
|
||||
FEATURE_SH_STANDALONE
|
||||
shells will try to exec /proc/self/exe if command's name matches
|
||||
some applet name; shells will do NOEXEC trick on NOEXEC applets
|
||||
|
||||
//TODO: split (same as for PREFER_APPLETS)
|
||||
|
||||
FEATURE_SH_NOFORK
|
||||
shells will do NOFORK trick on NOFORK applets
|
||||
|
Loading…
Reference in New Issue
Block a user