diff options
Diffstat (limited to 'util-linux')
| -rw-r--r-- | util-linux/Config.in | 6 | ||||
| -rw-r--r-- | util-linux/Kbuild | 1 | ||||
| -rw-r--r-- | util-linux/flock.c | 87 |
3 files changed, 94 insertions, 0 deletions
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@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; +} |