Newsgroups: comp.os.coherent
Subject: sh clones evaluated (was Re: C News)
Organization: Software Tool & Die Netnews Research Center
References: <138198@allan.sublink.org> <920725204@umunk.GUN.de>
	<9207260813.30@rmkhome.UUCP> <1992Jul27.200244.2456@acme.gen.nz>
	<Bs0x7K.2pp@world.std.com> <9207291604.00@rmkhome.UUCP>
	<Bs84t1.3Fx@world.std.com> <9208011403.38@rmkhome.UUCP>

I've reevaluated the allegedly-sh-compatible shells I have on hand (sh,
bash, ash, zsh and a redistributable ksh).  bash seems to have improved
since I last looked at it and seems to run inews and subordinates
correctly, and passes the diagnostic tests I extracted from inews and
anne.jones.  ash, zsh and redistributable ksh each fail three of the six
tests.  This saddens me, as ash is an elegant and relatively small piece
of work, whereas bash is bloated and complicated.

I've enclosed the test scripts (shx?), driver script (shx) and results
(log) below.  A couple caveats:  shx4 (a quoting test) uses the C News
getdate command; there may be newer versions of the shells tested - this
evaluation is decidedly informal.  Here's a quick summary: sh and bash
passed all tests; ash can't parse "<&$fd" and doesn't understand quoting;
redistributable ksh dumps core on a newline inside backquotes, doesn't
understand quoting, and botches waiting on background processes; zsh
doesn't understand sh quoting (in particular, it sees ! as a job control
character, even inside quotes), and botches waiting for background
processes.


# To unbundle, sh this file
echo log 1>&2
sed 's/^X//' >log <<'!'
X:; ./shx

sh:
X<&$fd	ok
nlbq	Mon Aug  3 02:45:00 EDT 1992
bang	geoff
quote	712824302
setbq	defmsgid=<1992Aug3.024502.6176@host>
bgwait	sleep done... wait 6187


bash:
X<&$fd	ok
nlbq	Mon Aug  3 02:45:09 EDT 1992
bang	geoff
quote	712824311
setbq	defmsgid=<1992Aug3.024512.6212@host>
bgwait	sleep done... wait 6223


ash:
X<&$fd	shx1: 4: Syntax error: Bad fd number
nlbq	Mon Aug  3 02:45:19 EDT 1992
bang	geoff
quote	getdate: `"now"' not a valid date

setbq	defmsgid=<1992Aug3.` echo 024521
bgwait	sleep done... wait 6241


ksh:
X<&$fd	ok
nlbq	./shx: 6248 Memory fault - core dumped
bang	geoff
quote	getdate: `"now"' not a valid date

setbq	defmsgid=<1992Aug3.024530.6257@host>
bgwait	no such job: 6265
wait 6265
sleep done... 

zsh:
X<&$fd	ok
nlbq	Mon Aug 3 02:45:36 EDT 1992
bang	shx3: event not found: /s/ [4]
quote	712824337
setbq	defmsgid=<..6290@host>
bgwait	shx7: unmatched " [9]
sleep done... 
X:; 
!
echo shx 1>&2
sed 's/^X//' >shx <<'!'
X#! /bin/sh
for cmd in sh bash ash ksh zsh
do
X	echo
X	echo $cmd:
X	for demo in shx?
X	do
X		$cmd $demo
X	done
done
!
echo shx1 1>&2
sed 's/^X//' >shx1 <<'!'
X# ash fails this one
echo -n '<&$fd	'
fd=3
echo ok <&$fd
!
echo shx2 1>&2
sed 's/^X//' >shx2 <<'!'
X# pd ksh fails this one
echo -n "nlbq	"
date=`
date`
echo "$date"
!
echo shx3 1>&2
sed 's/^X//' >shx3 <<'!'
X# zsh fails this one
echo -n 'bang	'
echo 'geoff    tty??   Aug  3 02:35' |
X    sed -e 's/[	 ].*//' -e '/!/s/^.*!//'
!
echo shx4 1>&2
sed 's/^X//' >shx4 <<'!'
X# ash, pd ksh fail this one
echo -n "quote	"
expiry="now"
timet="` getdate \"$expiry\" `"
echo "$timet"
!
echo shx5 1>&2
sed 's/^X//' >shx5 <<'!'
X# ash, zsh fail this one
echo -n "setbq	"
host=host
date="`date`"
echo defmsgid="`set $date; echo \<$6$2$3.\`  echo $4 | tr -d : \`.$$@$host\>`"
!
echo shx7 1>&2
sed 's/^X//' >shx7 <<'!'
X# pd ksh and zsh fail this one
echo -n "bgwait	"
X(
X	sleep 2
X	echo -n "sleep done... "
X) &
waitcmd="wait $!"
eval $waitcmd
echo "$waitcmd"
!
echo shx8 1>&2
sed 's/^X//' >shx8 <<'!'
X# in case gcx7 is really breaks this shell
sleep 3
echo
!
exit 0