flock: new applet

function                                             old     new   delta
flock_main                                             -     253    +253
packed_usage                                       26466   26498     +32
applet_names                                        2170    2176      +6
applet_main                                         1280    1284      +4
applet_nameofs                                       640     642      +2
applet_install_loc                                   160     161      +1
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 5/0 up/down: 298/0)             Total: 298 bytes

Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Timo Teras 2010-03-18 22:45:35 +01:00 committed by Denys Vlasenko
parent 8531d76a15
commit 892d4b6b3d
5 changed files with 105 additions and 0 deletions

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@ -161,6 +161,7 @@ IF_FLASH_ERASEALL(APPLET(flash_eraseall, _BB_DIR_USR_SBIN, _BB_SUID_DROP))
IF_FLASH_LOCK(APPLET_ODDNAME(flash_lock, flash_lock_unlock, _BB_DIR_USR_SBIN, _BB_SUID_DROP, flash_lock))
IF_FLASH_UNLOCK(APPLET_ODDNAME(flash_unlock, flash_lock_unlock, _BB_DIR_USR_SBIN, _BB_SUID_DROP, flash_unlock))
IF_FLASHCP(APPLET(flashcp, _BB_DIR_USR_SBIN, _BB_SUID_DROP))
IF_FLOCK(APPLET(flock, _BB_DIR_USR_BIN, _BB_SUID_DROP))
IF_FOLD(APPLET(fold, _BB_DIR_USR_BIN, _BB_SUID_DROP))
IF_FREE(APPLET(free, _BB_DIR_USR_BIN, _BB_SUID_DROP))
IF_FREERAMDISK(APPLET(freeramdisk, _BB_DIR_SBIN, _BB_SUID_DROP))

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@ -1312,6 +1312,16 @@
"\nOptions:" \
"\n -v Verbose" \
#define flock_trivial_usage \
"[-sxun] FD|FILE [[-c] PROG ARGS]"
#define flock_full_usage "\n\n" \
"[Un]lock file descriptor or file, then run PROG\n" \
"\nOptions:" \
"\n -s Shared lock" \
"\n -x Exclusive lock (default)" \
"\n -u Remove a lock from FD" \
"\n -n Fail rather than wait" \
#define fold_trivial_usage \
"[-bs] [-w WIDTH] [FILE]..."
#define fold_full_usage "\n\n" \

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@ -191,6 +191,12 @@ config FINDFS
WARNING:
With all submodules selected, it will add ~8k to busybox.
config FLOCK
bool "flock"
default y
help
Manage locks from shell scripts
config FREERAMDISK
bool "freeramdisk"
default n

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@ -13,6 +13,7 @@ lib-$(CONFIG_FDFLUSH) += freeramdisk.o
lib-$(CONFIG_FDFORMAT) += fdformat.o
lib-$(CONFIG_FDISK) += fdisk.o
lib-$(CONFIG_FINDFS) += findfs.o
lib-$(CONFIG_FLOCK) += flock.o
lib-$(CONFIG_FREERAMDISK) += freeramdisk.o
lib-$(CONFIG_FSCK_MINIX) += fsck_minix.o
lib-$(CONFIG_GETOPT) += getopt.o

87
util-linux/flock.c Normal file
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@ -0,0 +1,87 @@
/*
* Copyright (C) 2010 Timo Teras <timo.teras@iki.fi>
*
* This is free software, licensed under the GNU General Public License v2.
*/
#include <sys/file.h>
#include "libbb.h"
int flock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int flock_main(int argc UNUSED_PARAM, char **argv)
{
int mode, opt, fd;
enum {
OPT_s = (1 << 0),
OPT_x = (1 << 1),
OPT_n = (1 << 2),
OPT_u = (1 << 3),
OPT_c = (1 << 4),
};
#if ENABLE_LONG_OPTS
static const char getopt_longopts[] ALIGN1 =
"shared\0" No_argument "s"
"exclusive\0" No_argument "x"
"unlock\0" No_argument "u"
"nonblock\0" No_argument "n"
;
applet_long_options = getopt_longopts;
#endif
opt_complementary = "-1";
opt = getopt32(argv, "+sxnu");
argv += optind;
if (argv[1]) {
fd = open(argv[0], O_RDONLY|O_NOCTTY|O_CREAT, 0666);
if (fd < 0 && errno == EISDIR)
fd = open(argv[0], O_RDONLY|O_NOCTTY);
if (fd < 0)
bb_perror_msg_and_die("can't open '%s'", argv[0]);
//TODO? close_on_exec_on(fd);
} else {
fd = xatoi_u(argv[0]);
}
argv++;
/* If it is "flock FILE -c PROG", then -c isn't caught by getopt32:
* we use "+" in order to support "flock -opt FILE PROG -with-opts",
* we need to remove -c by hand.
* TODO: in upstream, -c 'PROG ARGS' means "run sh -c 'PROG ARGS'"
*/
if (argv[0]
&& argv[0][0] == '-'
&& ( (argv[0][1] == 'c' && !argv[0][2])
|| (ENABLE_LONG_OPTS && strcmp(argv[0] + 1, "-command") == 0)
)
) {
argv++;
}
if (OPT_s == LOCK_SH && OPT_x == LOCK_EX && OPT_n == LOCK_NB && OPT_u == LOCK_UN) {
/* With suitably matched constants, mode setting is much simpler */
mode = opt & (LOCK_SH + LOCK_EX + LOCK_NB + LOCK_UN);
if (!(mode & ~LOCK_NB))
mode |= LOCK_EX;
} else {
if (opt & OPT_u)
mode = LOCK_UN;
else if (opt & OPT_s)
mode = LOCK_SH;
else
mode = LOCK_EX;
if (opt & OPT_n)
mode |= LOCK_NB;
}
if (flock(fd, mode) != 0) {
if (errno == EWOULDBLOCK)
return EXIT_FAILURE;
bb_perror_nomsg_and_die();
}
if (argv[0])
return spawn_and_wait(argv);
return EXIT_SUCCESS;
}