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| author | Denys Vlasenko | 2021-06-20 13:08:50 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2021-06-20 13:08:50 +0200 |
| commit | ec3170ac9578d4a42423e5a966a8ba668df68337 (patch) | |
| tree | 33c96188abf62b845fdfea797b720a2aa8b5140a | |
| parent | 83dff7f43154cd41e4d2e5831060a2d2ddc6596e (diff) | |
| download | busybox-ec3170ac9578d4a42423e5a966a8ba668df68337.zip busybox-ec3170ac9578d4a42423e5a966a8ba668df68337.tar.gz | |
shred: implement -s SIZE
function old new delta
shred_main 337 391 +54
.rodata 103393 103395 +2
packed_usage 33666 33656 -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 56/-10) Total: 46 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | coreutils/shred.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/coreutils/shred.c b/coreutils/shred.c index 69fb3e8..4b95d19 100644 --- a/coreutils/shred.c +++ b/coreutils/shred.c @@ -15,14 +15,15 @@ //kbuild:lib-$(CONFIG_SHRED) += shred.o //usage:#define shred_trivial_usage -//usage: "[-fuz] [-n N] FILE..." +//usage: "[-fuz] [-n N] [-s SIZE] FILE..." //usage:#define shred_full_usage "\n\n" //usage: "Overwrite/delete FILEs\n" //usage: "\n -f Chmod to ensure writability" +//usage: "\n -s SIZE Size to write" //usage: "\n -n N Overwrite N times (default 3)" //usage: "\n -z Final overwrite with zeros" //usage: "\n -u Remove file" -//-x and -v are accepted but have no effect +//-x (exact: don't round up to 4k) and -v (verbose) are accepted but have no effect /* shred (GNU coreutils) 8.25: -f, --force change permissions to allow writing if necessary @@ -41,6 +42,7 @@ int shred_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int shred_main(int argc UNUSED_PARAM, char **argv) { + char *opt_s; int rand_fd = rand_fd; /* for compiler */ int zero_fd; unsigned num_iter = 3; @@ -52,9 +54,10 @@ int shred_main(int argc UNUSED_PARAM, char **argv) OPT_n = (1 << 3), OPT_v = (1 << 4), OPT_x = (1 << 5), + OPT_s = (1 << 6), }; - opt = getopt32(argv, "^" "fuzn:+vx" "\0" "-1"/*min 1 arg*/, &num_iter); + opt = getopt32(argv, "^" "fuzn:+vxs:" "\0" "-1"/*min 1 arg*/, &num_iter, &opt_s); argv += optind; zero_fd = xopen("/dev/zero", O_RDONLY); @@ -82,6 +85,11 @@ int shred_main(int argc UNUSED_PARAM, char **argv) if (fstat(fd, &sb) == 0 && sb.st_size > 0) { off_t size = sb.st_size; + if (opt & OPT_s) { + size = BB_STRTOOFF(opt_s, NULL, 0); /* accepts oct/hex */ + if (errno || size < 0) bb_show_usage(); + } + for (i = 0; i < num_iter; i++) { bb_copyfd_size(rand_fd, fd, size); fdatasync(fd); |