regress tests: remove use of unportable direct paths to commands

Many tests used direct paths to some commands, mostly /bin/echo and
/bin/cat. This is unportable (breaks on e.g. NixOS).
The correct way is to obtain the direct path using 'whence -p'.

There was also one use of '/usr/bin/pstack' in tests/comvario.sh
that seemed bogus. Apparently this was supposed to analyse a core
file after a crash. Even on Solaris and Linux, where that command
exists, the argument is documented to be a PID, not a core file. If
this ever worked anywhere, then it was system-specific enough to be
useless here, so I've removed it.

(cherry picked from commit 4563b8bc651cd9cb18dc73f56a041f7ac5534395)

src/cmd/ksh93/tests/basic.sh

@@ -36,6 +36,8 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+bincat=$(whence -p cat)
+binecho=$(whence -p echo)
 
 # test basic file operations like redirection, pipes, file expansion
 set -- \
@@ -155,7 +157,7 @@ then	err_exit "$foobar is not foobar"
 fi
 {
 	print foo
-	/bin/echo bar
+	"$binecho" bar
 	print bam
 } > $tmp/foobar
 if	[[ $( < $tmp/foobar) != $'foo\nbar\nbam' ]]
@@ -163,17 +165,17 @@ then	err_exit "output file pointer not shared correctly"
 fi
 cat > $tmp/foobar <<\!
 	print foo
-	/bin/echo bar
+	"$binecho" bar
 	print bam
 !
 chmod +x $tmp/foobar
-if	[[ $($tmp/foobar) != $'foo\nbar\nbam' ]]
+if	[[ $(export binecho; $tmp/foobar) != $'foo\nbar\nbam' ]]
 then	err_exit "script not working"
 fi
-if	[[ $($tmp/foobar | /bin/cat) != $'foo\nbar\nbam' ]]
+if	[[ $(export binecho; $tmp/foobar | "$bincat") != $'foo\nbar\nbam' ]]
 then	err_exit "script | cat not working"
 fi
-if	[[ $( $tmp/foobar) != $'foo\nbar\nbam' ]]
+if	[[ $(export binecho; $tmp/foobar) != $'foo\nbar\nbam' ]]
 then	err_exit "output file pointer not shared correctly"
 fi
 rm -f $tmp/foobar
@@ -181,13 +183,13 @@ x=$( (print foo) ; (print bar) )
 if	[[ $x != $'foo\nbar' ]]
 then	err_exit " ( (print foo);(print bar ) failed"
 fi
-x=$( (/bin/echo foo) ; (print bar) )
+x=$( ("$binecho" foo) ; (print bar) )
 if	[[ $x != $'foo\nbar' ]]
-then	err_exit " ( (/bin/echo);(print bar ) failed"
+then	err_exit " ( ("$binecho");(print bar ) failed"
 fi
-x=$( (/bin/echo foo) ; (/bin/echo bar) )
+x=$( ("$binecho" foo) ; ("$binecho" bar) )
 if	[[ $x != $'foo\nbar' ]]
-then	err_exit " ( (/bin/echo);(/bin/echo bar ) failed"
+then	err_exit " ( ("$binecho");("$binecho" bar ) failed"
 fi
 cat > $tmp/script <<\!
 if	[[ -p /dev/fd/0 ]]
@@ -221,7 +223,7 @@ if	[[ $x != "hello there" ]]
 then	err_exit "scripts in subshells fail"
 fi
 cd ~- || err_exit "cd back failed"
-x=$( (/bin/echo foo) 2> /dev/null )
+x=$( ("$binecho" foo) 2> /dev/null )
 if	[[ $x != foo ]]
 then	err_exit "subshell in command substitution fails"
 fi
@@ -233,15 +235,15 @@ then	err_exit "command substitution with stdout closed failed"
 fi
 exec >& 9
 cd $pwd
-x=$(cat <<\! | $SHELL
-/bin/echo | /bin/cat
-/bin/echo hello
+x=$(export binecho bincat; cat <<\! | $SHELL
+"$binecho" | "$bincat"
+"$binecho" hello
 !
 )
 if	[[ $x != $'\n'hello ]]
 then	err_exit "$SHELL not working when standard input is a pipe"
 fi
-x=$( (/bin/echo hello) 2> /dev/null )
+x=$( ("$binecho" hello) 2> /dev/null )
 if	[[ $x != hello ]]
 then	err_exit "subshell in command substitution with 1 closed fails"
 fi
@@ -265,22 +267,22 @@ fi
 trap - INT
 cat > $tmp/script <<- \!
 read line
-/bin/cat
+"$bincat"
 !
-if	[[ $($SHELL $tmp/script <<!
+if	[[ $(export bincat; $SHELL $tmp/script <<!
 one
 two
 !
 )	!= two ]]
 then	err_exit "standard input not positioned correctly"
 fi
-word=$(print $'foo\nbar' | { read line; /bin/cat;})
+word=$(print $'foo\nbar' | { read line; "$bincat";})
 if	[[ $word != bar ]]
-then	err_exit "pipe to { read line; /bin/cat;} not working"
+then	err_exit "pipe to { read line; $bincat;} not working"
 fi
-word=$(print $'foo\nbar' | ( read line; /bin/cat) )
+word=$(print $'foo\nbar' | ( read line; "$bincat") )
 if	[[ $word != bar ]]
-then	err_exit "pipe to ( read line; /bin/cat) not working"
+then	err_exit "pipe to ( read line; $bincat) not working"
 fi
 if	[[ $(print x{a,b}y) != 'xay xby' ]]
 then	err_exit 'brace expansion not working'

src/cmd/ksh93/tests/builtins.sh

@@ -36,6 +36,7 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+bincat=$(whence -p cat)
 
 # test shell builtin commands
 builtin getconf
@@ -101,7 +102,7 @@ hello \
 !
 [[ $REPLY == 'hello 	world' ]] || err_exit "read continuation2 failed"
 print "one\ntwo" | { read line
-	print $line | /bin/cat > /dev/null
+	print $line | "$bincat" > /dev/null
 	read line
 }
 read <<\!
@@ -559,6 +560,7 @@ builtin cat
 out=$tmp/seq.out
 for ((i=1; i<=11; i++)); do print "$i"; done >$out
 cmp -s <(print -- "$($bincat<( $bincat $out ) )") <(print -- "$(cat <( cat $out ) )") || err_exit "builtin cat differs from $bincat"
+builtin -d cat
 
 [[ $($SHELL -c '{ printf %R "["; print ok;}' 2> /dev/null) == ok ]] || err_exit $'\'printf %R "["\' causes shell to abort'
 

src/cmd/ksh93/tests/comvario.sh

@@ -529,11 +529,6 @@ print -v c2
         [[ "${out.stdout}" != '' ]] || err_exit "$0: Expected nonempty stdout."
        	[[ "${out.stderr}" == '' ]] || err_exit "$0: Expected empty stderr, got $(printf '%q\n' "${out.stderr}")"
 
-	if [[ -f 'core' && -x '/usr/bin/pstack' ]] ; then
-		pstack 'core'
-		rm 'core'
-	fi
-
 	return 0
 }
 

src/cmd/ksh93/tests/functions.sh

@@ -41,6 +41,7 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+binecho=$(whence -p echo)
 
 integer foo=33
 bar=bye
@@ -141,7 +142,7 @@ fi
 if	[[ $PWD != "$dir" ]]
 then	err_exit 'cd inside nested subshell changes $PWD'
 fi
-fun() /bin/echo hello
+fun() "$binecho" hello
 if	[[ $(fun) != hello ]]
 then	err_exit one line functions not working
 fi

src/cmd/ksh93/tests/glob.sh

@@ -105,7 +105,7 @@ case $* in
 'b B')	contrary=1 ;;
 b|B)	ignorant=1 ;;
 esac
-set -- $(LC_ALL=C /bin/sh -c 'echo [a-c]')
+set -- $(LC_ALL=C sh -c 'echo [a-c]')
 case $* in
 B)	aware=1 ;;
 esac

src/cmd/ksh93/tests/heredoc.sh

@@ -36,6 +36,7 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+bincat=$(whence -p cat)
 
 f=$tmp/here1
 g=$tmp/here2
@@ -125,7 +126,7 @@ done
 } > $f
 chmod +x "$f"
 $SHELL "$f" > /dev/null  || err_exit "large here-doc with command substitution fails"
-x=$(/bin/cat <<!
+x=$("$bincat" <<!
 $0
 !
 )
@@ -186,7 +187,7 @@ cat  > "$f" <<- '!!!!'
 	exec 0<&-
 	foobar()
 	{
-		/bin/cat <<- !
+		"$bincat" <<- !
 		foobar
 		!
 	}
@@ -212,7 +213,7 @@ cat  > "$f" <<- '!!!!'
 	EOF
 	print -r -- "$(foobar)"
 !!!!
-if	[[ $($SHELL  "$f") != foobar ]]
+if	[[ $(export bincat; "$SHELL" "$f") != foobar ]]
 then	err_exit	'here document with stdin closed failed'
 fi
 printf $'cat   <<# \\!!!\n\thello\n\t\tworld\n!!!' > $f

src/cmd/ksh93/tests/io.sh

@@ -478,9 +478,9 @@ print hello there world > $tmp/foobar
 $SHELL -c "sed  -e 's/there //' $tmp/foobar  >; $tmp/foobar"
 [[ $(<$tmp/foobar) == 'hello world' ]] || err_exit '>; redirection not working with -c on a simple command'
 
-rm -f "$tmp/junk"
+binfalse=$(whence -p false)
 for	(( i=1; i < 50; i++ ))
-do      out=$(/bin/ls "$tmp/junk" 2>/dev/null)
+do      out=$("$binfalse" 2>/dev/null)
 	if	(( $? == 0 ))
 	then    err_exit 'wrong error code with redirection'
 		break

src/cmd/ksh93/tests/options.sh

@@ -41,6 +41,7 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+bincat=$(whence -p cat)
 
 if	[[ $( ${SHELL-ksh} -s hello<<-\!
 		print $1
@@ -367,7 +368,7 @@ pipeline=(
 	( nopipefail=1 pipefail=1 command='true|true|false' )
 	( nopipefail=1 pipefail=1 command='false|false|false' )
 	( nopipefail=0 pipefail=0 command='true|true|true' )
-	( nopipefail=0 pipefail=0 command='print hi|(sleep 1;/bin/cat)>/dev/null' )
+	( nopipefail=0 pipefail=0 command='print hi|(sleep 1;"$bincat")>/dev/null' )
 )
 set --nopipefail
 for ((i = 0; i < ${#pipeline[@]}; i++ ))

src/cmd/ksh93/tests/quoting.sh

@@ -27,6 +27,8 @@ alias err_exit='err_exit $LINENO'
 
 Command=${0##*/}
 integer Errors=0
+binecho=$(whence -p echo)
+
 if	[[ 'hi there' != "hi there" ]]
 then	err_exit "single quotes not the same as double quotes"
 fi
@@ -184,7 +186,7 @@ fi
 if	[[ $x$ != '$hi$' ]]
 then	err_exit ' $x$, with x=$hi, does not expand to $hi$'
 fi
-set -- $(/bin/echo foo;sleep 1;/bin/echo bar)
+set -- $("$binecho" foo; sleep 1; "$binecho" bar)
 if	[[ $# != 2 ]]
 then	err_exit 'word splitting after command substitution not working'
 fi

src/cmd/ksh93/tests/restricted.sh

@@ -36,6 +36,7 @@ tmp=$(
 	exit 1
 }
 trap 'cd / && rm -rf "$tmp"' EXIT
+binecho=$(whence -p echo)
 
 # test restricted shell
 pwd=$PWD
@@ -57,7 +58,7 @@ ln -s $SHELL rksh
 PATH=$PWD:$PATH
 rksh -c  '[[ -o restricted ]]' || err_exit 'restricted option not set'
 [[ $(rksh -c 'print hello') == hello ]] || err_exit 'unable to run print'
-check_restricted /bin/echo || err_exit '/bin/echo not resticted'
+check_restricted "$binecho" || err_exit "$binecho not resticted"
 check_restricted ./echo || err_exit './echo not resticted'
 check_restricted 'SHELL=ksh' || err_exit 'SHELL assignment not resticted'
 check_restricted 'PATH=/bin' || err_exit 'PATH assignment not resticted'
@@ -70,7 +71,7 @@ print 'echo hello' > script
 chmod +x ./script
 ! check_restricted script ||  err_exit 'script without builtins should run in restricted mode'
 check_restricted ./script ||  err_exit 'script with / in name should not run in restricted mode'
-print '/bin/echo hello' > script
+printf '%q hello\n' "$binecho" > script
 ! check_restricted script ||  err_exit 'script with pathnames should run in restricted mode'
 print 'echo hello> file' > script
 ! check_restricted script ||  err_exit 'script with output redirection should run in restricted mode'

src/cmd/ksh93/tests/sigchld.sh

@@ -155,7 +155,7 @@ done
 (( d==2000 )) ||  err_exit "trap '' CHLD  causes side effects d=$d"
 trap - CHLD
 
-x=$($SHELL 2> /dev/null -ic '/bin/notfound; sleep .5 & sleep 1;jobs')
+x=$($SHELL 2> /dev/null -ic '/dev/null/notfound; sleep .5 & sleep 1;jobs')
 [[ $x == *Done* ]] || err_exit 'SIGCHLD blocked after notfound'
 x=$($SHELL 2> /dev/null  -ic 'kill -0 12345678901234567876; sleep .5 & sleep 1;jobs')
 [[ $x == *Done* ]] || err_exit 'SIGCHLD blocked after error message'

src/cmd/ksh93/tests/signal.sh

@@ -283,18 +283,18 @@ then	float s=$SECONDS
 	(( SECONDS-s < 4 )) && err_exit 'parent completes early'
 fi
 
-yes=$(whence -p yes)
-if	[[ $yes ]]
-then	for exp in TERM VTALRM PIPE
+yes() for ((;;)); do print y; done
+
+	for exp in TERM VTALRM PIPE
 	do	if	[[ ${SIG[$exp]} ]]
 		then	{
-				$SHELL <<- EOF
+				bindate=$(whence -p date) "$SHELL" <<- EOF
 				foo() { return 0; }
 				trap foo EXIT
 				{ sleep 2; kill -$exp \$\$; sleep 3; kill -0 \$\$ && kill -KILL \$\$; } &
-				$yes |
+				yes |
 				while read yes
-				do	(/bin/date; sleep .1)
+				do	("\$bindate"; sleep .1)
 				done > /dev/null
 				EOF
     			} 2>> /dev/null
@@ -302,7 +302,6 @@ then	for exp in TERM VTALRM PIPE
     			[[ $exp == $got ]] || err_exit "kill -$exp \$\$ failed, required termination by signal '$got'"
 		fi
 	done
-fi
 
 SECONDS=0
 $SHELL 2> /dev/null -c 'sleep 2 && kill $$ & trap "print done; exit 3" EXIT; (sleep 5); print finished' > $tmp/sig

src/cmd/ksh93/tests/subshell.sh

@@ -39,6 +39,7 @@ trap 'cd / && rm -rf "$tmp"' EXIT
 
 builtin getconf
 bincat=$(PATH=$(getconf PATH) whence -p cat)
+binecho=$(PATH=$(getconf PATH) whence -p echo)
 
 z=()
 z.foo=( [one]=hello [two]=(x=3 y=4) [three]=hi)
@@ -466,9 +467,9 @@ exp=ok
 got=$($SHELL -c "$cmd" 2>&1)
 [[ $got == "$exp" ]] ||  err_exit "'$cmd' failed -- expected '$exp', got '$got'"
 
-cmd='eval "for i in 1 2; do eval /bin/echo x; done"'
+cmd='eval '\''for i in 1 2; do eval "\"\$binecho\" x"; done'\'
 exp=$'x\nx'
-got=$($SHELL -c "$cmd")
+got=$(export binecho; $SHELL -c "$cmd")
 if	[[ $got != "$exp" ]]
 then	EXP=$(printf %q "$exp")
 	GOT=$(printf %q "$got")
@@ -482,7 +483,7 @@ $SHELL -c 'sleep 20 & pid=$!; { x=$( ( seq 60000 ) );kill -9 $pid;}&;wait $pid'
 
 (.sh.foo=foobar)
 [[ ${.sh.foo} == foobar ]] && err_exit '.sh subvariables in subshells remain set'
-[[ $($SHELL -c 'print 1 | : "$(/bin/cat <(/bin/cat))"') ]] && err_exit 'process substitution not working correctly in subshells'
+[[ $($SHELL -c 'print 1 | : "$("$bincat" <("$bincat"))"') ]] && err_exit 'process substitution not working correctly in subshells'
 
 # config hang bug
 integer i