With GNU Coreutils 9.4, both "test -a -a -a" and "test -o -o -o" fail:
$ export POSIXLY_CORRECT=1 $ /usr/bin/test -a -a -a ; echo $? /usr/bin/test: ‘-a’: unary operator expected 2 $ /usr/bin/test -o -o -o ; echo $? /usr/bin/test: ‘-o’: unary operator expected 2 According to POSIX, they should return 0. https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html says for 3 arguments: If $2 is a binary primary, perform the binary test of $1 and $3. Here, $2 is -a and -o respectively, which are binary primaries. And both $1 and $3 are non-null strings. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
