test in various shells

"`test`" operator robustness in various shells

2010-01-08 (see recent changes)

Variations in the handling of arguments to test among the various traditional and POSIX conformant implementations.

command	sh V7	sh Sys3	sh SVR2 Ultrix	sh SVR3 sunos413	sh SVR4 -sunos510	ksh86a epix	ksh88i sunos59	ksh93-t	pdksh- 5.2.14	posh- 0.5.4	posh- 0.6.17	bash- 1.14.7	bash-4.1	ash-orig	ash-0.2-linux	ash-0.3.4	dash- 0.4.26	dash- 0.5.5.1	zsh- 4.0.4	zsh- 4.3.9
a=x; test -n "$a" && echo test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1	test1
a=!; test -n "$a" \|\| echo nok
a==; test -n "$a" \|\| echo nok		arg exp	arg exp	arg exp	arg exp	arg exp	arg exp
a=-; test -n "$a" \|\| echo nok
a=-n; test -n "$a" \|\| echo nok
a='('; test -n "$a" \|\| echo nok														syn error

a=x; b=x; test "$a" = "$b" && echo test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2	test2
a=x; b=!; test "$a" = "$b" && echo nok
a=x; b==; test "$a" = "$b" && echo nok
a=x; b=-; test "$a" = "$b" && echo nok
a=x; b=-n; test "$a" = "$b" && echo nok
a=x; b='('; test "$a" = "$b" && echo nok														syn error
a=!; b=x; test "$a" = "$b" && echo nok	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp					unary op exp		syn error	unexp op		unexp op
a=!; b=!; test "$a" = "$b" \|\| echo nok	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp					unary op exp		syn error	unexp op		unexp op
a=!; b==; test "$a" = "$b" && echo nok	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp					unary op exp		syn error	arg exp		arg exp
a=!; b=-; test "$a" = "$b" && echo nok	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp					unary op exp		syn error	unexp op		unexp op
a=!; b=-n; test "$a" = "$b" && echo nok	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp					unary op exp		syn error	unexp op		unexp op
a==; b=x; test "$a" = "$b" && echo nok
a==; b=!; test "$a" = "$b" && echo nok
a==; b==; test "$a" = "$b" \|\| echo nok
a==; b=-; test "$a" = "$b" && echo nok
a==; b=-n; test "$a" = "$b" && echo nok
a=-; b=x; test "$a" = "$b" && echo nok
a=-; b=!; test "$a" = "$b" && echo nok
a=-; b==; test "$a" = "$b" && echo nok
a=-; b=-; test "$a" = "$b" \|\| echo nok
a=-; b=-n; test "$a" = "$b" && echo nok
a=-n; b=x; test "$a" = "$b" && echo nok	nok													syn error	unexp op
a=-n; b=!; test "$a" = "$b" && echo nok	nok													syn error	unexp op
a=-n; b==; test "$a" = "$b" && echo nok	nok													syn error	unexp op
a=-n; b=-; test "$a" = "$b" && echo nok	nok													syn error	unexp op
a=-n; b=-n; test "$a" = "$b" \|\| echo nok														syn error	unexp op

a=x; b=x; test -n "$a" -a -n "$b" && echo test3	test3	test3	test3	test3	test3	test3	test3	test3	test3	unexp op	test3	test3	test3	test3	test3	test3	test3	test3	test3	test3
a=x; b=!; test -n "$a" -a -n "$b" \|\| echo nok										unexp op
a=x; b==; test -n "$a" -a -n "$b" \|\| echo nok		syn error	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp		unexp op
a=x; b=-; test -n "$a" -a -n "$b" \|\| echo nok										unexp op
a=x; b=-n; test -n "$a" -a -n "$b" \|\| echo nok										unexp op
a=!; b=x; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a=!; b=!; test -n "$a" -a -n "$b" \|\| echo nok		arg exp								unexp op				syn error
a=!; b==; test -n "$a" -a -n "$b" \|\| echo nok			arg exp	arg exp	arg exp	arg exp	arg exp	arg exp		unexp op				syn error
a=!; b=-; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a=!; b=-n; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a==; b=x; test -n "$a" -a -n "$b" \|\| echo nok		arg exp	nok	too many args	nok	syn error	nok	nok		unexp op		too many args	too many args			extra arg -n	unexp op	unexp op		too many args
a==; b=!; test -n "$a" -a -n "$b" \|\| echo nok			nok	too many args	nok	syn error	nok	nok		unexp op		too many args	too many args			extra arg -n	unexp op	unexp op		too many args
a==; b==; test -n "$a" -a -n "$b" \|\| echo nok			nok	too many args	nok	syn error	nok	nok		unexp op		too many args	too many args			extra arg -n	unexp op	unexp op		too many args
a==; b=-; test -n "$a" -a -n "$b" \|\| echo nok		syn error	nok	too many args	nok	syn error	nok	nok		unexp op		too many args	too many args			extra arg -n	unexp op	unexp op		too many args
a==; b=-n; test -n "$a" -a -n "$b" \|\| echo nok		syn error	nok	too many args	nok	syn error	nok	nok		unexp op		too many args	too many args			extra arg -n	unexp op	unexp op		too many args
a=-; b=x; test -n "$a" -a -n "$b" \|\| echo nok		syn error								unexp op
a=-; b=!; test -n "$a" -a -n "$b" \|\| echo nok		syn error								unexp op
a=-; b==; test -n "$a" -a -n "$b" \|\| echo nok			arg exp	arg exp	arg exp	arg exp	arg exp	arg exp		unexp op
a=-; b=-; test -n "$a" -a -n "$b" \|\| echo nok		arg exp								unexp op
a=-; b=-n; test -n "$a" -a -n "$b" \|\| echo nok										unexp op
a=-n; b=x; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a=-n; b=!; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a=-n; b==; test -n "$a" -a -n "$b" \|\| echo nok		arg exp	arg exp	arg exp	arg exp	arg exp	arg exp	arg exp		unexp op				syn error
a=-n; b=-; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
a=-n; b=-n; test -n "$a" -a -n "$b" \|\| echo nok										unexp op				syn error
command	sh V7	sh Sys3	sh SVR2 Ultrix	sh SVR3 sunos413	sh SVR4 -sunos510	ksh86a epix	ksh88i sunos59	ksh93-t	pdksh- 5.2.14	posh- 0.5.4	posh- 0.6.17	bash- 1.14.7	bash-4.1	ash-orig	ash-0.2-linux	ash-0.3.4	dash- 0.4.26	dash- 0.5.5.1	zsh- 4.0.4	zsh- 4.3.9

About the table:

error messages are only printed abbreviated
(for instance "too many args" instead of "script: line xx: test: too many arguments", or "unexp op" instead of "-a: unexpected operator")
the V7 shell has no test built-in yet, these are the results from the external command
Some shells are not listed explicitly, because the results were identical to a related shell in the table:
- sh on SunOS 5.1 and 5.5 behave like sh SunOS5.10
- ksh88g and xpg4-ksh on SunOS5 behave like ksh88i
- bash-1.05 behaves like bash-1.14.7, except that it doesn't accept '!' anywhere and prints ";: Event not found.",
  because history expansion wrongly is not disabled in noninteractive mode.
- bash-1.14.0 behaves like bash-1.14.7
- bash-2.05b, bash-3.0, bash-3.2.48, bash-4.0.35 behave like bash-4.1.0. The same applies to POSIX mode.
- ksh93-k behaves like ksh93-t
- ash-0.3.8-37, ash-0.4.0, dash-0.4.26 behave like dash-0.5.5.1
- zsh-3.0.8 behaves like zsh-4.0.4
The alternative [[...]] is not required by POSIX (but allowed),
it is not implemented in the traditional Bourne shell, bash-1, posh, ash and all its descendants
See the traditional Bourne shell family about the sh ... shell varinats in the table,
and Ash (Almquist) shell variants about the ash-* and dash-* variants.

The results were collected with a method like this

    $ cat tests
    a=x; test -n "$a" && echo test1
    a=!; test -n "$a" || echo nok
    [...]

    $ cat loop
    while IFS= read -r line ; do
        {print HTML}
        for i in {shells}
        do
            log=`$i -ec "$line" 2>&1`; ret=$?
            log=`printf '%s' "$log"|tr -d '\n'`
            printf {HTML with "$log"}
        done
    done < tests

...and then piped through sed to substitute the error messages.
The very script is longer, because results from different systems have to get interspersed.

Comments to <mascheck@in-ulm.de>

<http://www.in-ulm.de/~mascheck/various/test/>

"test" operator robustness in various shells

"`test`" operator robustness in various shells