From 97e305025e987e77da488133ded31c1e81a0282b Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Wed, 16 Nov 2022 07:08:13 +0900 Subject: [PATCH] sed: check errors writing file with sed -i MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit sed would currently not error if write failed when modifying a file. This can be reproduced with the following 'script': $ sudo mount -t tmpfs tmpfs -o size=1M /tmp/m $ sudo chmod 777 /tmp/m $ echo foo > /tmp/m/foo $ dd if=/dev/zero of=/tmp/m/fill bs=4k dd: error writing '/tmp/m/fill': No space left on device 256+0 records in 255+0 records out 1044480 bytes (1.0 MB, 1020 KiB) copied, 0.00234567 s, 445 MB/s $ busybox sed -i -e 's/.*/bar/' /tmp/m/foo $ echo $? 0 $ cat /tmp/m/foo new behaviour: $ echo foo > /tmp/m/foo $ ./busybox sed -i -e 's/.*/bar/' /tmp/m/foo sed: write error $ echo $? 4 $ cat /tmp/m/foo foo function old new delta sed_main 754 801 +47 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/0 up/down: 47/0) Total: 47 bytes text data bss dec hex filename 66957 2398 1552 70907 114fb busybox_old 67004 2398 1552 70954 1152a busybox_unstripped Signed-off-by: Dominique Martinet --- editors/sed.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/editors/sed.c b/editors/sed.c index 00dde60be..6179c5e80 100644 --- a/editors/sed.c +++ b/editors/sed.c @@ -1648,6 +1648,11 @@ int sed_main(int argc UNUSED_PARAM, char **argv) fchown(nonstdoutfd, statbuf.st_uid, statbuf.st_gid); process_files(); + fflush(G.nonstdout); + if (ferror(G.nonstdout)) { + xfunc_error_retval = 4; /* It's what gnu sed exits with... */ + bb_simple_error_msg_and_die(bb_msg_write_error); + } fclose(G.nonstdout); G.nonstdout = stdout;