path: root/tests/exec.test

# Commands covered:  exec
#
# This file contains a collection of tests for one or more of the Tcl
# built-in commands.  Sourcing this file into Tcl runs the tests and
# generates output for errors.  No output means no errors were found.
#
# Copyright (c) 1991-1994 The Regents of the University of California.
# Copyright (c) 1994-1997 Sun Microsystems, Inc.
# Copyright (c) 1998-1999 by Scriptics Corporation.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: exec.test,v 1.9 2001/11/23 01:26:02 das Exp $

if {[lsearch [namespace children] ::tcltest] == -1} {
    package require tcltest
    namespace import -force ::tcltest::*
}

# All tests require the "exec" command.
# Skip them if exec is not defined.
set ::tcltest::testConstraints(execCommandExists) [expr {[info commands exec] != ""}]

set f [open echo w]
puts $f {
    puts -nonewline [lindex $argv 0]
    foreach str [lrange $argv 1 end] {
	puts -nonewline " $str"
    }
    puts {}
    exit
}
close $f

set f [open cat w]
puts $f {
    if {$argv == {}} {
	set argv -
    }
    foreach name $argv {
	if {$name == "-"} {
	    set f stdin
	} elseif {[catch {open $name r} f] != 0} {
	    puts stderr $f
	    continue
	}
	while {[eof $f] == 0} {
	    puts -nonewline [read $f]
	}
	if {$f != "stdin"} {
	    close $f
	}
    }
    exit
}
close $f

set f [open wc w]
puts $f {
    set data [read stdin]
    set lines [regsub -all "\n" $data {} dummy]
    set words [regsub -all "\[^ \t\n]+" $data {} dummy]
    set chars [string length $data]
    puts [format "%8.d%8.d%8.d" $lines $words $chars]
    exit
}
close $f

set f [open sh w]
puts $f {
    if {[lindex $argv 0] != "-c"} {
	error "sh: unexpected arguments $argv"
    }
    set cmd [lindex $argv 1]
    lappend cmd ";"

    set newcmd {}
    
    foreach arg $cmd {
	if {$arg == ";"} {
	    eval exec >@stdout 2>@stderr [list [info nameofexecutable]] $newcmd
	    set newcmd {}
	    continue
	}
	if {$arg == "1>&2"} {
	    set arg >@stderr
	}
	lappend newcmd $arg
    }
    exit
}
close $f

set f [open sleep w]
puts $f {
    after [expr $argv*1000]
    exit
}
close $f

set f [open exit w]
puts $f {
    exit $argv
}
close $f

# Basic operations.

test exec-1.1 {basic exec operation} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo a b c
} "a b c"
test exec-1.2 {pipelining} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo a b c d | $::tcltest::tcltest cat | $::tcltest::tcltest cat
} "a b c d"
test exec-1.3 {pipelining} {execCommandExists stdio} {
    set a [exec $::tcltest::tcltest echo a b c d | $::tcltest::tcltest cat | $::tcltest::tcltest wc]
    list [scan $a "%d %d %d" b c d] $b $c
} {3 1 4}
set arg {12345678901234567890123456789012345678901234567890}
set arg "$arg$arg$arg$arg$arg$arg"
test exec-1.4 {long command lines} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo $arg
} $arg
set arg {}

# I/O redirection: input from Tcl command.

test exec-2.1 {redirecting input from immediate source} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat << "Sample text"
} {Sample text}
test exec-2.2 {redirecting input from immediate source} {execCommandExists stdio} {
    exec << "Sample text" $::tcltest::tcltest cat | $::tcltest::tcltest cat
} {Sample text}
test exec-2.3 {redirecting input from immediate source} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat << "Sample text" | $::tcltest::tcltest cat
} {Sample text}
test exec-2.4 {redirecting input from immediate source} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat | $::tcltest::tcltest cat << "Sample text"
} {Sample text}
test exec-2.5 {redirecting input from immediate source} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat "<<Joined to arrows"
} {Joined to arrows}
test exec-2.6 {redirecting input from immediate source, with UTF} {execCommandExists stdio} {
    # If this fails, it may give back:
    # "\uC3\uA9\uC3\uA0\uC3\uBC\uC3\uB1"
    # If it does, this means that the UTF -> external conversion did not 
    # occur before writing out the temp file.
    exec $::tcltest::tcltest cat << "\uE9\uE0\uFC\uF1"
} "\uE9\uE0\uFC\uF1"

# I/O redirection: output to file.

file delete gorp.file
test exec-3.1 {redirecting output to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "Some simple words" > gorp.file
    exec $::tcltest::tcltest cat gorp.file
} "Some simple words"
test exec-3.2 {redirecting output to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "More simple words" | >gorp.file $::tcltest::tcltest cat | $::tcltest::tcltest cat
    exec $::tcltest::tcltest cat gorp.file
} "More simple words"
test exec-3.3 {redirecting output to file} {execCommandExists stdio} {
    exec > gorp.file $::tcltest::tcltest echo "Different simple words" | $::tcltest::tcltest cat | $::tcltest::tcltest cat
    exec $::tcltest::tcltest cat gorp.file
} "Different simple words"
test exec-3.4 {redirecting output to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "Some simple words" >gorp.file
    exec $::tcltest::tcltest cat gorp.file
} "Some simple words"
test exec-3.5 {redirecting output to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "First line" >gorp.file
    exec $::tcltest::tcltest echo "Second line" >> gorp.file
    exec $::tcltest::tcltest cat gorp.file
} "First line\nSecond line"
test exec-3.6 {redirecting output to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "First line" >gorp.file
    exec $::tcltest::tcltest echo "Second line" >>gorp.file
    exec $::tcltest::tcltest cat gorp.file
} "First line\nSecond line"
test exec-3.7 {redirecting output to file} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "Line 1"
    flush $f
    exec $::tcltest::tcltest echo "More text" >@ $f
    exec $::tcltest::tcltest echo >@$f "Even more"
    puts $f "Line 3"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} "Line 1\nMore text\nEven more\nLine 3"

# I/O redirection: output and stderr to file.

file delete gorp.file
test exec-4.1 {redirecting output and stderr to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "test output" >& gorp.file
    exec $::tcltest::tcltest cat gorp.file
} "test output"
test exec-4.2 {redirecting output and stderr to file} {execCommandExists stdio} {
    list [exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" >&gorp.file] \
	    [exec $::tcltest::tcltest cat gorp.file]
} {{} {foo bar}}
test exec-4.3 {redirecting output and stderr to file} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "first line" > gorp.file
    list [exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" >>&gorp.file] \
	    [exec $::tcltest::tcltest cat gorp.file]
} "{} {first line\nfoo bar}"
test exec-4.4 {redirecting output and stderr to file} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "Line 1"
    flush $f
    exec $::tcltest::tcltest echo "More text" >&@ $f
    exec $::tcltest::tcltest echo >&@$f "Even more"
    puts $f "Line 3"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} "Line 1\nMore text\nEven more\nLine 3"
test exec-4.5 {redirecting output and stderr to file} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "Line 1"
    flush $f
    exec >&@ $f $::tcltest::tcltest sh -c "echo foo bar 1>&2"
    exec >&@$f $::tcltest::tcltest sh -c "echo xyzzy 1>&2"
    puts $f "Line 3"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} "Line 1\nfoo bar\nxyzzy\nLine 3"

# I/O redirection: input from file.

if { [set ::tcltest::testConstraints(execCommandExists)] } {
exec $::tcltest::tcltest echo "Just a few thoughts" > gorp.file
}
test exec-5.1 {redirecting input from file} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat < gorp.file
} {Just a few thoughts}
test exec-5.2 {redirecting input from file} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat | $::tcltest::tcltest cat < gorp.file
} {Just a few thoughts}
test exec-5.3 {redirecting input from file} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat < gorp.file | $::tcltest::tcltest cat
} {Just a few thoughts}
test exec-5.4 {redirecting input from file} {execCommandExists stdio} {
    exec < gorp.file $::tcltest::tcltest cat | $::tcltest::tcltest cat
} {Just a few thoughts}
test exec-5.5 {redirecting input from file} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat <gorp.file
} {Just a few thoughts}
test exec-5.6 {redirecting input from file} {execCommandExists stdio} {
    set f [open gorp.file r]
    set result [exec $::tcltest::tcltest cat <@ $f]
    close $f
    set result
} {Just a few thoughts}
test exec-5.7 {redirecting input from file} {execCommandExists stdio} {
    set f [open gorp.file r]
    set result [exec <@$f $::tcltest::tcltest cat]
    close $f
    set result
} {Just a few thoughts}

# I/O redirection: standard error through a pipeline.

test exec-6.1 {redirecting stderr through a pipeline} {execCommandExists stdio} {
    exec $::tcltest::tcltest sh -c "echo foo bar" |& $::tcltest::tcltest cat
} "foo bar"
test exec-6.2 {redirecting stderr through a pipeline} {execCommandExists stdio} {
    exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" |& $::tcltest::tcltest cat
} "foo bar"
test exec-6.3 {redirecting stderr through a pipeline} {execCommandExists stdio} {
    exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" \
	|& $::tcltest::tcltest sh -c "echo second msg 1>&2 ; cat" |& $::tcltest::tcltest cat
} "second msg\nfoo bar"

# I/O redirection: combinations.

file delete gorp.file2
test exec-7.1 {multiple I/O redirections} {execCommandExists stdio} {
    exec << "command input" > gorp.file2 $::tcltest::tcltest cat < gorp.file
    exec $::tcltest::tcltest cat gorp.file2
} {Just a few thoughts}
test exec-7.2 {multiple I/O redirections} {execCommandExists stdio} {
    exec < gorp.file << "command input" $::tcltest::tcltest cat
} {command input}

# Long input to command and output from command.

set a "0123456789 xxxxxxxxx abcdefghi ABCDEFGHIJK\n"
set a [concat $a $a $a $a]
set a [concat $a $a $a $a]
set a [concat $a $a $a $a]
set a [concat $a $a $a $a]
test exec-8.1 {long input and output} {execCommandExists stdio} {
    exec $::tcltest::tcltest cat << $a
} $a

# More than 20 arguments to exec.

test exec-8.1 {long input and output} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23}

# Commands that return errors.

test exec-9.1 {commands returning errors} {execCommandExists stdio} {
    set x [catch {exec gorp456} msg]
    list $x [string tolower $msg] [string tolower $errorCode]
} {1 {couldn't execute "gorp456": no such file or directory} {posix enoent {no such file or directory}}}
test exec-9.2 {commands returning errors} {execCommandExists stdio} {
    string tolower [list [catch {exec $::tcltest::tcltest echo foo | foo123} msg] $msg $errorCode]
} {1 {couldn't execute "foo123": no such file or directory} {posix enoent {no such file or directory}}}
test exec-9.3 {commands returning errors} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest sleep 1 | $::tcltest::tcltest exit 43 | $::tcltest::tcltest sleep 1} msg] $msg
} {1 {child process exited abnormally}}
test exec-9.4 {commands returning errors} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest exit 43 | $::tcltest::tcltest echo "foo bar"} msg] $msg
} {1 {foo bar
child process exited abnormally}}
test exec-9.5 {commands returning errors} {execCommandExists stdio} {
    list [catch {exec gorp456 | $::tcltest::tcltest echo a b c} msg] [string tolower $msg]
} {1 {couldn't execute "gorp456": no such file or directory}}
test exec-9.6 {commands returning errors} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest sh -c "echo error msg 1>&2"} msg] $msg
} {1 {error msg}}
test exec-9.7 {commands returning errors} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest sh -c "echo error msg 1>&2" \
		     | $::tcltest::tcltest sh -c "echo error msg 1>&2"} msg] $msg
} {1 {error msg
error msg}}
test exec-9.8 {commands returning errors} {execCommandExists stdio} {
    set f [open err w]
    puts $f {
	puts stdout out
	puts stderr err
    }
    close $f
    list [catch {exec $::tcltest::tcltest err} msg] $msg
} {1 {out
err}}

# Errors in executing the Tcl command, as opposed to errors in the
# processes that are invoked.

test exec-10.1 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec} msg] $msg
} {1 {wrong # args: should be "exec ?switches? arg ?arg ...?"}}
test exec-10.2 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec | cat} msg] $msg
} {1 {illegal use of | or |& in command}}
test exec-10.3 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat |} msg] $msg
} {1 {illegal use of | or |& in command}}
test exec-10.4 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat | | cat} msg] $msg
} {1 {illegal use of | or |& in command}}
test exec-10.5 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat | |& cat} msg] $msg
} {1 {illegal use of | or |& in command}}
test exec-10.6 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat |&} msg] $msg
} {1 {illegal use of | or |& in command}}
test exec-10.7 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat <} msg] $msg
} {1 {can't specify "<" as last word in command}}
test exec-10.8 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >} msg] $msg
} {1 {can't specify ">" as last word in command}}
test exec-10.9 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat <<} msg] $msg
} {1 {can't specify "<<" as last word in command}}
test exec-10.10 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >>} msg] $msg
} {1 {can't specify ">>" as last word in command}}
test exec-10.11 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >&} msg] $msg
} {1 {can't specify ">&" as last word in command}}
test exec-10.12 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >>&} msg] $msg
} {1 {can't specify ">>&" as last word in command}}
test exec-10.13 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >@} msg] $msg
} {1 {can't specify ">@" as last word in command}}
test exec-10.14 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat <@} msg] $msg
} {1 {can't specify "<@" as last word in command}}
test exec-10.15 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat < a/b/c} msg] [string tolower $msg]
} {1 {couldn't read file "a/b/c": no such file or directory}}
test exec-10.16 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat << foo > a/b/c} msg] [string tolower $msg]
} {1 {couldn't write file "a/b/c": no such file or directory}}
test exec-10.17 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat << foo > a/b/c} msg] [string tolower $msg]
} {1 {couldn't write file "a/b/c": no such file or directory}}
set f [open gorp.file w]
test exec-10.18 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat <@ $f} msg] $msg
} "1 {channel \"$f\" wasn't opened for reading}"
close $f
set f [open gorp.file r]
test exec-10.19 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec cat >@ $f} msg] $msg
} "1 {channel \"$f\" wasn't opened for writing}"
close $f
test exec-10.20 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec ~non_existent_user/foo/bar} msg] $msg
} {1 {user "non_existent_user" doesn't exist}}
test exec-10.21 {errors in exec invocation} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest true | ~xyzzy_bad_user/x | false} msg] $msg
} {1 {user "xyzzy_bad_user" doesn't exist}}

# Commands in background.

test exec-11.1 {commands in background} {execCommandExists stdio} {
    set x [lindex [time {exec $::tcltest::tcltest sleep 2 &}] 0]
    expr $x<1000000
} 1
test exec-11.2 {commands in background} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest echo a &b} msg] $msg
} {0 {a &b}}
test exec-11.3 {commands in background} {execCommandExists stdio} {
    llength [exec $::tcltest::tcltest sleep 1 &]
} 1
test exec-11.4 {commands in background} {execCommandExists stdio} {
    llength [exec $::tcltest::tcltest sleep 1 | $::tcltest::tcltest sleep 1 | $::tcltest::tcltest sleep 1 &]
} 3
test exec-11.5 {commands in background} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f { catch { exec [info nameofexecutable] echo foo & } }
    close $f
    string compare "foo" [exec $::tcltest::tcltest gorp.file]
} 0

# Make sure that background commands are properly reaped when
# they eventually die.

if { [set ::tcltest::testConstraints(execCommandExists)] } {
exec $::tcltest::tcltest sleep 3
}
test exec-12.1 {reaping background processes} \
	{execCommandExists stdio unixOnly nonPortable} {
    for {set i 0} {$i < 20} {incr i} {
	exec echo foo > /dev/null &
    }
    exec sleep 1
    catch {exec ps | fgrep "echo foo" | fgrep -v fgrep | wc} msg
    lindex $msg 0
} 0
test exec-12.2 {reaping background processes} \
	{execCommandExists stdio unixOnly nonPortable} {
    exec sleep 2 | sleep 2 | sleep 2 &
    catch {exec ps | fgrep -i "sleep" | fgrep -i -v fgrep | wc} msg
    set x [lindex $msg 0]
    exec sleep 3
    catch {exec ps | fgrep -i "sleep" | fgrep -i -v fgrep | wc} msg
    list $x [lindex $msg 0]
} {3 0}
test exec-12.3 {reaping background processes} \
	{execCommandExists stdio unixOnly nonPortable} {
    exec sleep 1000 &
    exec sleep 1000 &
    set x [exec ps | fgrep "sleep" | fgrep -v fgrep]
    set pids {}
    foreach i [split $x \n] {
	lappend pids [lindex $i 0]
    }
    foreach i $pids {
	catch {exec kill -STOP $i}
    }
    catch {exec ps | fgrep "sleep" | fgrep -v fgrep | wc} msg
    set x [lindex $msg 0]

    foreach i $pids {
	catch {exec kill -KILL $i}
    }
    catch {exec ps | fgrep "sleep" | fgrep -v fgrep | wc} msg
    list $x [lindex $msg 0]
} {2 0}

# Make sure "errorCode" is set correctly.

test exec-13.1 {setting errorCode variable} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest cat < a/b/c} msg] [string tolower $errorCode]
} {1 {posix enoent {no such file or directory}}}
test exec-13.2 {setting errorCode variable} {execCommandExists stdio} {
    list [catch {exec $::tcltest::tcltest cat > a/b/c} msg] [string tolower $errorCode]
} {1 {posix enoent {no such file or directory}}}
test exec-13.3 {setting errorCode variable} {execCommandExists stdio} {
    set x [catch {exec _weird_cmd_} msg]
    list $x [string tolower $msg] [lindex $errorCode 0] \
	    [string tolower [lrange $errorCode 2 end]]
} {1 {couldn't execute "_weird_cmd_": no such file or directory} POSIX {{no such file or directory}}}

# Switches before the first argument

test exec-14.1 {-keepnewline switch} {execCommandExists stdio} {
    exec -keepnewline $::tcltest::tcltest echo foo
} "foo\n"
test exec-14.2 {-keepnewline switch} {execCommandExists stdio} {
    list [catch {exec -keepnewline} msg] $msg
} {1 {wrong # args: should be "exec ?switches? arg ?arg ...?"}}
test exec-14.3 {unknown switch} {execCommandExists stdio} {
    list [catch {exec -gorp} msg] $msg
} {1 {bad switch "-gorp": must be -keepnewline or --}}
test exec-14.4 {-- switch} {execCommandExists stdio} {
    list [catch {exec -- -gorp} msg] [string tolower $msg]
} {1 {couldn't execute "-gorp": no such file or directory}}

# Redirecting standard error separately from standard output

test exec-15.1 {standard error redirection} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "First line" > gorp.file
    list [exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" 2> gorp.file] \
	    [exec $::tcltest::tcltest cat gorp.file]
} {{} {foo bar}}
test exec-15.2 {standard error redirection} {execCommandExists stdio} {
    list [exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" \
		| $::tcltest::tcltest echo biz baz >gorp.file 2> gorp.file2] \
	    [exec $::tcltest::tcltest cat gorp.file] \
	    [exec $::tcltest::tcltest cat gorp.file2]
} {{} {biz baz} {foo bar}}
test exec-15.3 {standard error redirection} {execCommandExists stdio} {
    list [exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" \
	        | $::tcltest::tcltest echo biz baz 2>gorp.file > gorp.file2] \
	    [exec $::tcltest::tcltest cat gorp.file] \
	    [exec $::tcltest::tcltest cat gorp.file2]
} {{} {foo bar} {biz baz}}
test exec-15.4 {standard error redirection} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "Line 1"
    flush $f
    exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" 2>@ $f
    puts $f "Line 3"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} {Line 1
foo bar
Line 3}
test exec-15.5 {standard error redirection} {execCommandExists stdio} {
    exec $::tcltest::tcltest echo "First line" > gorp.file
    exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" 2>> gorp.file
    exec $::tcltest::tcltest cat gorp.file
} {First line
foo bar}
test exec-15.6 {standard error redirection} {execCommandExists stdio} {
    exec $::tcltest::tcltest sh -c "echo foo bar 1>&2" > gorp.file2 2> gorp.file \
	    >& gorp.file 2> gorp.file2 | $::tcltest::tcltest echo biz baz
    list [exec $::tcltest::tcltest cat gorp.file] [exec $::tcltest::tcltest cat gorp.file2]
} {{biz baz} {foo bar}}

test exec-16.1 {flush output before exec} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "First line"
    exec $::tcltest::tcltest echo "Second line" >@ $f
    puts $f "Third line"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} {First line
Second line
Third line}
test exec-16.2 {flush output before exec} {execCommandExists stdio} {
    set f [open gorp.file w]
    puts $f "First line"
    exec $::tcltest::tcltest << {puts stderr {Second line}} >&@ $f > gorp.file2
    puts $f "Third line"
    close $f
    exec $::tcltest::tcltest cat gorp.file
} {First line
Second line
Third line}

test exec-17.1 { inheriting standard I/O } {execCommandExists stdio} {
    set f [open script w]
    puts $f {close stdout
	set f [open gorp.file w]
	catch {exec [info nameofexecutable] echo foobar &}
	exec [info nameofexecutable] sleep 2
	close $f
    }
    close $f
    catch {exec $::tcltest::tcltest script} result
    set f [open gorp.file r]
    lappend result [read $f]
    close $f
    set result
} {{foobar
}}

# cleanup
file delete script gorp.file gorp.file2
file delete echo cat wc sh sleep exit
file delete err
::tcltest::cleanupTests
return