test "$msg" = "Hello"
# does the variable msg have the value "Hello"?
test "$x" -gt "$y"
# does x contain a numeric value larger than y?
msg="hello there"
test $msg = Hello
# Error: expands to "test hello there = Hello"?
test "$x" -ge 10 -a "$x" -le 20
# is the value of x in range 10..20?
test -r xyz -a -d xyz
# is the file xyz a readable directory?
[ -r xyz -a -d xyz ]
# alternative syntax; requires closing ]
|