[PATCH v2] truncate: new applet
Ari Sundholm
ari at tuxera.com
Wed Mar 4 14:11:53 UTC 2015
From: Ari Sundholm <ari at tuxera.com>
bloat-o-meter:
function old new delta
.rodata 154411 154491 +80
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 80/0) Total: 80 bytes
v2: Make dd and truncate share a common suffix struct.
Signed-off-by: Ari Sundholm <ari at tuxera.com>
---
coreutils/dd.c | 31 +++++-----------------
coreutils/truncate.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/libbb.h | 1 +
libbb/xatonum.c | 19 ++++++++++++++
4 files changed, 99 insertions(+), 25 deletions(-)
create mode 100644 coreutils/truncate.c
diff --git a/coreutils/dd.c b/coreutils/dd.c
index 3024970..53a843c 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -99,25 +99,6 @@ enum {
ofd = STDOUT_FILENO,
};
-static const struct suffix_mult dd_suffixes[] = {
- { "c", 1 },
- { "w", 2 },
- { "b", 512 },
- { "kB", 1000 },
- { "kD", 1000 },
- { "k", 1024 },
- { "K", 1024 }, /* compat with coreutils dd (it also accepts KB and KD, TODO?) */
- { "MB", 1000000 },
- { "MD", 1000000 },
- { "M", 1024*1024 },
- { "GB", 1000000000 },
- { "GD", 1000000000 },
- { "G", 1024*1024*1024 },
- /* "D" suffix for decimal is not in coreutils manpage, looks like it's deprecated */
- /* coreutils also understands TPEZY suffixes for tera- and so on, with B suffix for decimal */
- { "", 0 }
-};
-
struct globals {
off_t out_full, out_part, in_full, in_part;
#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
@@ -326,11 +307,11 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
#if ENABLE_FEATURE_DD_IBS_OBS
if (what == OP_ibs) {
/* Must fit into positive ssize_t */
- ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+ ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
/*continue;*/
}
if (what == OP_obs) {
- obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+ obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
/*continue;*/
}
if (what == OP_conv) {
@@ -356,22 +337,22 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
}
#endif
if (what == OP_bs) {
- ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+ ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
obs = ibs;
/*continue;*/
}
/* These can be large: */
if (what == OP_count) {
G.flags |= FLAG_COUNT;
- count = XATOU_SFX(val, dd_suffixes);
+ count = XATOU_SFX(val, cwbkMG_suffixes);
/*continue;*/
}
if (what == OP_seek) {
- seek = XATOU_SFX(val, dd_suffixes);
+ seek = XATOU_SFX(val, cwbkMG_suffixes);
/*continue;*/
}
if (what == OP_skip) {
- skip = XATOU_SFX(val, dd_suffixes);
+ skip = XATOU_SFX(val, cwbkMG_suffixes);
/*continue;*/
}
if (what == OP_if) {
diff --git a/coreutils/truncate.c b/coreutils/truncate.c
new file mode 100644
index 0000000..36b2f2c
--- /dev/null
+++ b/coreutils/truncate.c
@@ -0,0 +1,73 @@
+/*
+ * Mini truncate implementation for busybox
+ *
+ * Copyright (C) 2015 by Ari Sundholm <ari at tuxera.com>
+ *
+ * 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-$(CONFIG_TRUNCATE) += truncate.o
+//applet:IF_TRUNCATE(APPLET(truncate, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//usage:#define truncate_trivial_usage
+//usage: "[-c] -s SIZE FILE..."
+//usage:#define truncate_full_usage "\n\n"
+//usage: "Truncate FILEs to the given size.\n"
+//usage: "\n -c Do not create any files."
+//usage: "\n -s SIZE Truncate to SIZE."
+//usage:
+//usage:#define truncate_example_usage
+//usage: "$ truncate -s 1G foo"
+
+#include "libbb.h"
+
+#if ENABLE_LFS
+# define XATOU_SFX xatoull_sfx
+#else
+# define XATOU_SFX xatoul_sfx
+#endif
+
+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("truncate: no files specified!\n");
+ return 1;
+ }
+
+ 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;
+}
diff --git a/include/libbb.h b/include/libbb.h
index be792d6..e4fcf7c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -861,6 +861,7 @@ struct suffix_mult {
};
extern const struct suffix_mult bkm_suffixes[];
#define km_suffixes (bkm_suffixes + 1)
+extern const struct suffix_mult cwbkMG_suffixes[];
#include "xatonum.h"
/* Specialized: */
diff --git a/libbb/xatonum.c b/libbb/xatonum.c
index 6f4e023..19b54fb 100644
--- a/libbb/xatonum.c
+++ b/libbb/xatonum.c
@@ -75,3 +75,22 @@ const struct suffix_mult bkm_suffixes[] = {
{ "m", 1024*1024 },
{ "", 0 }
};
+
+const struct suffix_mult cwbkMG_suffixes[] = {
+ { "c", 1 },
+ { "w", 2 },
+ { "b", 512 },
+ { "kB", 1000 },
+ { "kD", 1000 },
+ { "k", 1024 },
+ { "K", 1024 }, /* compat with coreutils dd (it also accepts KB and KD, TODO?) */
+ { "MB", 1000000 },
+ { "MD", 1000000 },
+ { "M", 1024*1024 },
+ { "GB", 1000000000 },
+ { "GD", 1000000000 },
+ { "G", 1024*1024*1024 },
+ /* "D" suffix for decimal is not in coreutils manpage, looks like it's deprecated */
+ /* coreutils also understands TPEZY suffixes for tera- and so on, with B suffix for decimal */
+ { "", 0 }
+};
--
1.9.1
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