From: Pádraig Brady Date: Fri, 28 May 2010 18:25:23 +0000 (+0100) Subject: truncate: improve handling of non regular files X-Git-Tag: v8.6~154 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=200501052edde61747a16cd0af60fa925ef87bfb;p=thirdparty%2Fcoreutils.git truncate: improve handling of non regular files Previously we copied `dd` and suppressed error messages when truncating neither regular files or shared mem objects. This was valid for `dd`, as truncation is ancillary to copying it may also do, but for `truncate` we should display all errors. Also we used the st_size from non regular files which is undefined, so we display an error when the user tries this. * src/truncate (do_truncate): Error when referencing the size of non regular files or non shared memory objects. Display all errors returned by ftruncate(). (main): Error when referencing the size of non regular files or non shared memory objects. Don't suppress error messages for any file types that can't be opened for writing. * tests/misc/truncate-dir-fail: Check that referencing the size of a directory is not supported. * tests/misc/truncate-fifo: Ensure the test doesn't hang by using the `timeout` command. Don't test the return from running ftruncate on the fifo as it's system dependent as to whether this fails or not. NEWS: Mention the change in behavior. Reported by Jim Meyering. --- diff --git a/NEWS b/NEWS index 7a294f4a2a..7d3343ba62 100644 --- a/NEWS +++ b/NEWS @@ -15,6 +15,8 @@ GNU coreutils NEWS -*- outline -*- sort -g now uses long doubles for greater range and precision. truncate now supports setting file sizes relative to a reference file. + Also errors are no longer suppressed for unsupported file types, and + relative sizes are restricted to supported file types. * Noteworthy changes in release 8.5 (2010-04-23) [stable] diff --git a/src/truncate.c b/src/truncate.c index 08090ab20a..493f7f7912 100644 --- a/src/truncate.c +++ b/src/truncate.c @@ -160,21 +160,21 @@ do_ftruncate (int fd, char const *fname, off_t ssize, off_t rsize, { uintmax_t const fsize = rsize < 0 ? sb.st_size : rsize; - if (rsize < 0 && sb.st_size < 0) + if (rsize < 0) /* fstat used above to get size. */ { - /* Complain only for a regular file, a directory, - or a shared memory object, as POSIX 1003.1-2004 specifies - ftruncate's behavior only for these file types. */ - if (S_ISREG (sb.st_mode) || S_ISDIR (sb.st_mode) - || S_TYPEISSHM (&sb)) + if (!S_ISREG (sb.st_mode) && !S_TYPEISSHM (&sb)) { - /* overflow is the only reason I can think - this would ever go negative for the above types */ + error (0, 0, _("cannot get the size of %s"), quote (fname)); + return 1; + } + if (sb.st_size < 0) + { + /* Sanity check. Overflow is the only reason I can think + this would ever go negative. */ error (0, 0, _("%s has unusable, apparently negative size"), quote (fname)); return 1; } - return 0; } if (rel_mode == rm_min) @@ -215,26 +215,10 @@ do_ftruncate (int fd, char const *fname, off_t ssize, off_t rsize, if (ftruncate (fd, nsize) == -1) /* note updates mtime & ctime */ { - /* Complain only when ftruncate fails on a regular file, a - directory, or a shared memory object, as POSIX 1003.1-2004 - specifies ftruncate's behavior only for these file types. - For example, do not complain when Linux kernel 2.4 ftruncate - fails on /dev/fd0. */ - int const ftruncate_errno = errno; - if (fstat (fd, &sb) != 0) - { - error (0, errno, _("cannot fstat %s"), quote (fname)); - return 1; - } - else if (S_ISREG (sb.st_mode) || S_ISDIR (sb.st_mode) - || S_TYPEISSHM (&sb)) - { - error (0, ftruncate_errno, - _("truncating %s at %" PRIdMAX " bytes"), quote (fname), - (intmax_t) nsize); - return 1; - } - return 0; + error (0, errno, + _("failed to truncate %s at %" PRIdMAX " bytes"), quote (fname), + (intmax_t) nsize); + return 1; } return 0; @@ -362,9 +346,13 @@ main (int argc, char **argv) if (ref_file) { + /* FIXME: Maybe support getting size of block devices. */ struct stat sb; if (stat (ref_file, &sb) != 0) error (EXIT_FAILURE, errno, _("cannot stat %s"), quote (ref_file)); + if (!S_ISREG (sb.st_mode) && !S_TYPEISSHM (&sb)) + error (EXIT_FAILURE, 0, _("cannot get the size of %s"), + quote (ref_file)); if (!got_size) size = sb.st_size; else @@ -384,18 +372,7 @@ main (int argc, char **argv) `truncate -s0 .` should gen EISDIR error */ if (!(no_create && errno == ENOENT)) { - int const open_errno = errno; - struct stat sb; - if (stat (fname, &sb) == 0) - { - /* Complain only for a regular file, a directory, - or a shared memory object, as POSIX 1003.1-2004 specifies - ftruncate's behavior only for these file types. */ - if (!S_ISREG (sb.st_mode) && !S_ISDIR (sb.st_mode) - && !S_TYPEISSHM (&sb)) - continue; - } - error (0, open_errno, _("cannot open %s for writing"), + error (0, errno, _("cannot open %s for writing"), quote (fname)); errors++; } diff --git a/tests/misc/truncate-dir-fail b/tests/misc/truncate-dir-fail index d2ecf2fe6b..fe33857a2a 100755 --- a/tests/misc/truncate-dir-fail +++ b/tests/misc/truncate-dir-fail @@ -26,4 +26,7 @@ fi # truncate on dir not allowed truncate -s+0 . && fail=1 +# getting the size of a dir is not allowed +truncate -r. file && fail=1 + Exit $fail diff --git a/tests/misc/truncate-fifo b/tests/misc/truncate-fifo index 8e2276daba..a4c36cb90b 100755 --- a/tests/misc/truncate-fifo +++ b/tests/misc/truncate-fifo @@ -1,5 +1,5 @@ #!/bin/sh -# Make sure truncate works on fifos without hanging or errors +# Make sure truncate works on fifos without hanging # Copyright (C) 2008-2010 Free Software Foundation, Inc. @@ -23,9 +23,9 @@ fi . $srcdir/test-lib.sh -mkfifo_or_skip_ "fifo" +mkfifo_or_skip_ fifo - -truncate -s0 "fifo" || fail=1 +timeout 10 truncate -s0 fifo +test "$?" = 124 && fail=1 Exit $fail