[git commit master] flock: new applet
Denys Vlasenko
vda.linux at googlemail.com
Thu Mar 18 21:45:35 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=892d4b6b3d7e9950ff3708ca957e1e0590dd5a2d
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
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 at iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
include/applets.h | 1 +
include/usage.h | 10 ++++++
util-linux/Config.in | 6 +++
util-linux/Kbuild | 1 +
util-linux/flock.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 105 insertions(+), 0 deletions(-)
create mode 100644 util-linux/flock.c
diff --git a/include/applets.h b/include/applets.h
index 2d784bd..83c1792 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -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))
diff --git a/include/usage.h b/include/usage.h
index f4259a1..0aea010 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -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" \
diff --git a/util-linux/Config.in b/util-linux/Config.in
index f04511b..d0d8df3 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -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
diff --git a/util-linux/Kbuild b/util-linux/Kbuild
index 72a2ef1..99e3efe 100644
--- a/util-linux/Kbuild
+++ b/util-linux/Kbuild
@@ -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
diff --git a/util-linux/flock.c b/util-linux/flock.c
new file mode 100644
index 0000000..78b1e4b
--- /dev/null
+++ b/util-linux/flock.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2010 Timo Teras <timo.teras at 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;
+}
--
1.6.3.3
More information about the busybox-cvs
mailing list