configure shell game

[Predrag Zečević]

Well, linux is OS which changed /bin/sh to be /bin/bash
(so, changing /bin/sh to /usr/bin/env bash should/moight work everywhere)

So, that is not nonsense, but very old standard ...

Regards.

On 2026-06-02 15:28, Darren Tucker via openssh-unix-dev wrote:
> Hi.
> 
> I was recently reminded of this nonsense from the Solaris /bin/sh while
> running a regression test:
> 
> run test proxy-connect.sh ...
> [...]/proxy-connect.sh: warning: line 6: `...` obsolete, use $(...)
> [...]/proxy-connect.sh: warning: line 6: `...` obsolete, use $(...)
> [...]/proxy-connect.sh: warning: line 15: `...` obsolete, use $(...)
> 
> One way to fix that is to use a shell that doesn't suck, of which there
> are several candidates.  Configure even already finds them: I started
> on this a while back but chickened out as it was very close to a release
> at the time.
> 
> There are some potential complications.  Configure has several SHELL
> variables, which AFAICT are:
> 
> 1) SHELL: /bin/sh or equivalent, set real early in the guts of configure.
> 
> 2) CONFIG_SHELL: The shell configure will feed itself to if it decides, or
>     is told, that /bin/sh is insufficiently capable to run it.
> 
> 3) TEST_MINUS_S_SH: one we set configure, which is used for the sole
>     purpose of doing a single 'test -S [socket]' on what may be an prngd
>     socket.
> 
> 4) SH: one I added that gets passed to SHELL in the Makefile when I started
>     this the first time.
> 
> 5) TEST_SHELL: this is the shell the regression tests use to run themselves.
> 
> Unfortutely someone (almost certainly me) did this:
> 
> AC_SUBST([TEST_SHELL], [sh])
> 
> and
> 
> TEST_SHELL=$SHELL  # let configure find us a capable shell
> 
> which sorta works, but is often the least-optimal of the candidates (#1)
> for running the regression tests.
> 
> I want to merge #3 into #4 and use that instead.  I also want to rename
> it, since while 'SH' is relatively accurate, it's *real* hard to grep
> for in a project named "OpenSSH".
> 
> Can anyone see any down sides of doing this?
> 
> diff --git a/.github/configs b/.github/configs
> index a7bb698e2..5131e65b3 100755
> --- a/.github/configs
> +++ b/.github/configs
> @@ -279,9 +279,7 @@ case "${TARGET_HOST}" in
>   	# These are slow real or virtual machines so skip the slowest tests
>   	# (which tend to be thw ones that transfer lots of data) so that the
>   	# test run does not time out.
> -	# The agent-restrict test fails due to some quoting issue when run
> -	# with sh or ksh so specify bash for now.
> -	TEST_TARGET="t-exec unit TEST_SHELL=bash"
> +	TEST_TARGET="t-exec unit"
>   	SKIP_LTESTS="rekey sftp"
>   	;;
>       dfly58*|dfly60*)
> diff --git a/Makefile.in b/Makefile.in
> index 730e598d0..19cceb150 100644
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -1,4 +1,4 @@
> -SHELL=@SH@
> +SHELL=@POSIX_SHELL@
>   
>   AUTORECONF=autoreconf
>   
> @@ -30,7 +30,7 @@ SSH_SK_HELPER=$(libexecdir)/ssh-sk-helper
>   PRIVSEP_PATH=@PRIVSEP_PATH@
>   SSH_PRIVSEP_USER=@SSH_PRIVSEP_USER@
>   STRIP_OPT=@STRIP_OPT@
> -TEST_SHELL=@TEST_SHELL@
> +TEST_SHELL=@POSIX_SHELL@
>   BUILDDIR=@abs_top_builddir@
>   SK_STANDALONE=@SK_STANDALONE@
>   COMPATINCLUDES="$(BUILDDIR)/@COMPATINCLUDES@"
> diff --git a/configure.ac b/configure.ac
> index 530c8e316..36a6b34d5 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -53,17 +53,11 @@ AC_CHECK_TOOLS([AR], [ar])
>   AC_PATH_PROG([CAT], [cat])
>   AC_PATH_PROG([KILL], [kill])
>   AC_PATH_PROG([SED], [sed])
> -AC_PATH_PROG([TEST_MINUS_S_SH], [bash])
> -AC_PATH_PROG([TEST_MINUS_S_SH], [ksh])
> -AC_PATH_PROG([TEST_MINUS_S_SH], [sh])
> -AC_PATH_PROG([SH], [bash])
> -AC_PATH_PROG([SH], [ksh])
> -AC_PATH_PROG([SH], [sh])
> +AC_PATH_PROGS([POSIX_SHELL], [bash ksh sh])
>   AC_PATH_PROG([GROFF], [groff])
>   AC_PATH_PROGS([NROFF], [nroff awf])
>   AC_PATH_PROG([MANDOC], [mandoc])
>   AC_PATH_TOOL([PKGCONFIG], [pkg-config], [no])
> -AC_SUBST([TEST_SHELL], [sh])
>   
>   dnl select manpage formatter to be used to build "cat" format pages.
>   if test "x$MANDOC" != "x" ; then
> @@ -1282,7 +1276,6 @@ if (setsockopt(s, IPPROTO_IP, IP_TOS, &one, sizeof(one)) == -1)
>   		fi
>   		],
>   	)
> -	TEST_SHELL=$SHELL	# let configure find us a capable shell
>   	;;
>   *-*-sunos4*)
>   	CPPFLAGS="$CPPFLAGS -DSUNOS4"
> @@ -1327,7 +1320,6 @@ if (setsockopt(s, IPPROTO_IP, IP_TOS, &one, sizeof(one)) == -1)
>   	AC_DEFINE([BROKEN_SETREGID])
>   	AC_DEFINE([PASSWD_NEEDS_USERNAME], [1], [must supply username to passwd])
>   	AC_DEFINE([LOCKED_PASSWD_STRING], ["*LK*"])
> -	TEST_SHELL=$SHELL	# let configure find us a capable shell
>   	;;
>   # UnixWare 7.x, OpenUNIX 8
>   *-*-sysv5*)
> @@ -1340,7 +1332,6 @@ if (setsockopt(s, IPPROTO_IP, IP_TOS, &one, sizeof(one)) == -1)
>   	AC_DEFINE([BROKEN_SETREGID])
>   	AC_DEFINE([PASSWD_NEEDS_USERNAME])
>   	AC_DEFINE([BROKEN_TCGETATTR_ICANON])
> -	TEST_SHELL=$SHELL	# let configure find us a capable shell
>   	case "$host" in
>   	*-*-sysv5SCO_SV*)	# SCO OpenServer 6.x
>   		maildir=/var/spool/mail
> @@ -1379,7 +1370,6 @@ if (setsockopt(s, IPPROTO_IP, IP_TOS, &one, sizeof(one)) == -1)
>   	AC_DEFINE([PASSWD_NEEDS_USERNAME])
>   	AC_CHECK_FUNCS([getluid setluid])
>   	MANTYPE=man
> -	TEST_SHELL=$SHELL	# let configure find us a capable shell
>   	SKIP_DISABLE_LASTLOG_DEFINE=yes
>   	;;
>   *-dec-osf*)
> @@ -3649,7 +3639,7 @@ AC_ARG_WITH([prngd-socket],
>   			AC_MSG_CHECKING([for PRNGD/EGD socket])
>   			# Insert other locations here
>   			for sock in /var/run/egd-pool /dev/egd-pool /etc/entropy; do
> -				if test -r $sock && $TEST_MINUS_S_SH -c "test -S $sock -o -p $sock" ; then
> +				if test -r $sock && $POSIX_SHELL -c "test -S $sock -o -p $sock" ; then
>   					PRNGD_SOCKET="$sock"
>   					AC_DEFINE_UNQUOTED([PRNGD_SOCKET], ["$PRNGD_SOCKET"])
>   					break;
> @@ -5908,6 +5898,7 @@ CFLAGS_NOPIE=`echo "$CFLAGS" | sed 's/^-fPIE //;s/ -fPIE//g'`
>   AC_SUBST([LDFLAGS_NOPIE])
>   AC_SUBST([CFLAGS_NOPIE])
>   AC_SUBST([COMPATINCLUDES])
> +AC_SUBST([POSIX_SHELL])
>   
>   AC_EXEEXT
>   AC_CONFIG_FILES([Makefile buildpkg.sh opensshd.init openssh.xml \
> 

-- 
Predrag Zečević