On March 5, 2015 2:28:28 PM GMT+01:00, Ari Sundholm <[email protected]> wrote: >From: Ari Sundholm <[email protected]> > >bloat-o-meter: > >function old new >delta >.rodata 154411 154480 >+69 >------------------------------------------------------------------------------ >(add/remove: 0/0 grow/shrink: 1/0 up/down: 69/0) Total: >69 bytes
Wrong baseline? Why is that C impl better than a shell script around dd? Thanks, > >v2: Make dd and truncate share a common suffix struct. >v3: Split suffix struct move into separate commit, make applet NOFORK, >adjust > error message. >v4: Use bb_error_msg_and_die() instead of bb_error_msg() + xfunc_die(). > >Signed-off-by: Ari Sundholm <[email protected]> >--- >coreutils/truncate.c | 73 >++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) > create mode 100644 coreutils/truncate.c > >diff --git a/coreutils/truncate.c b/coreutils/truncate.c >new file mode 100644 >index 0000000..5d7c4f9 >--- /dev/null >+++ b/coreutils/truncate.c >@@ -0,0 +1,73 @@ >+/* >+ * Mini truncate implementation for busybox >+ * >+ * Copyright (C) 2015 by Ari Sundholm <[email protected]> >+ * >+ * Licensed under GPLv2 or later, see file LICENSE in this source >tree. >+ */ >+ >+//config:config TRUNCATE >+//config: bool "truncate" >+//config: default y >+//config: help >+//config: truncate truncates files to a given size. If a file does >+//config: not exist, it is created unless told otherwise. >+ >+//kbuild:lib-$(CONFIG_TRUNCATE) += truncate.o >+//applet:IF_TRUNCATE(APPLET_NOFORK(truncate, truncate, BB_DIR_USR_BIN, >BB_SUID_DROP, truncate)) >+ >+//usage:#define truncate_trivial_usage >+//usage: "[-c] -s SIZE FILE..." >+//usage:#define truncate_full_usage "\n\n" >+//usage: "Truncate FILEs to the given size.\n" >+//usage: "\n -c Do not create any files." >+//usage: "\n -s SIZE Truncate to SIZE." >+//usage: >+//usage:#define truncate_example_usage >+//usage: "$ truncate -s 1G foo" >+ >+#include "libbb.h" >+ >+#if ENABLE_LFS >+# define XATOU_SFX xatoull_sfx >+#else >+# define XATOU_SFX xatoul_sfx >+#endif >+ >+/* This is a NOFORK applet. Be very careful! */ >+ >+int truncate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; >+int truncate_main(int argc UNUSED_PARAM, char **argv) { >+ unsigned opts; >+ int flags = O_CREAT|O_RDWR; >+ int fd; >+ char *size_str; >+ off_t size; >+ >+ enum { >+ OPT_NOCREATE = (1 << 0), >+ OPT_SIZE = (1 << 1), >+ }; >+ >+ opt_complementary = "s"; >+ opts = getopt32(argv, "cs:", &size_str); >+ >+ argv += optind; >+ if (!*argv) >+ bb_error_msg_and_die("no files specified!"); >+ >+ if (opts & OPT_NOCREATE) >+ flags = O_RDWR; >+ >+ size = XATOU_SFX(size_str, cwbkMG_suffixes); >+ >+ while (*argv) { >+ fd = xopen(*argv, flags); >+ if (ftruncate(fd, size) == -1) >+ bb_perror_msg_and_die("ftruncate failed"); >+ xclose(fd); >+ ++argv; >+ } >+ >+ return 0; >+} _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
