On 2/16/22 23:57, Ulrich Eckhardt wrote:
In order to fix that bug in the above script, you currently have to
replace `grep ...` with `grep ... || [ $? = 1 ]`, which is not really
readable.
Actually, appending something "|| test $? -eq 1" looks readable to me;
plus, it already works and is portable to non-GNU systems which is a
plus. Furthermore, it also works with other programs that also return
0,1,>1 depending on success,failure,error (e.g., 'cmp', 'diff', 'sort'),
and it doesn't sound like much of a win to add unportable --pipe options
to every such program.
And it's not just commands like 'cmp' and 'grep'. The following causes
Bash to exit on GNU/Linux:
set -eo pipefail
cat /usr/share/dict/american-english | grep -l '^'
This is not because of anything 'grep' does, as 'grep' exits with status
zero. It's because 'cat' exits with nonzero status. Surely we shouldn't
add a --pipe option to 'cat' too.
Scripts that use "set -eo pipefail" need to be verrrry careful
regardless of what we do with 'grep'; and if they are careful it won't
help much to add a --pipe option to 'grep'.
