redirecting output from a format

mpeters has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to redirect the output from the Test::Harness::runtests() method into a scalar. I'm using IO::Scalar to do the job of redirecting STDOUT and it works just like expected, except for one spot. When a subtest fails, Test::Harness uses a format (associated with STDOUT) to create the pretty report that shows which subtests failed, etc. I would also like to capture this report into my scalar, but I haven't been able to do it.

    my $test_output;
    my $IO = IO::Scalar->new(\$test_output);
    $IO->format_name('STDOUT');
    $IO->format_top_name('STDOUT_TOP');
    select($IO);
    eval {
        runtests(@testfiles);
    };
    $test_output .= $@ if ($@);
    select(STDOUT);
[download]

After doing this, my scalar ($test_output) does not contain the failure report and neither is it printed to the screen. When I try this:

    my $test_output;
    tie(*STDOUT, 'IO::Scalar', \$test_output);
    eval {
        runtests(@testfiles);
    };
    $test_output .= $@ if ($@);
    untie(*STDOUT);
[download]

I end up with the same data in $test_output, but the failure report is printed to the screen. Still not what I want... Any suggestions?

Comment on redirecting output from a format Select or Download Code

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Re: redirecting output from a format by brian_d_foy (Abbot) on Nov 30, 2004 at 05:46 UTC
I ran into a similar problem and came up with a very ugly, don't-try-this-at-home solution I posted in use.perl `my( $totals, $failed ) = eval { local @INC = @INC; local STDOUT; # Shut up Test::Harness! local STDERR; # Yeah, you too! my $MM = ExtUtils::MM->new(); # and you! unshift @INC, map { File::Spec->rel2abs($_) } @{ $MM }{ qw( INST_LIB INST_ARCHLIB ) }; Test::Harness::_run_all_tests( @test_files ) };` [download] I could use Test::Harness::Straps to do this all myself, but at the time I was on a bit of a deadline and wasn't sure I could reproduce everything _run_all_tests did, so I just wrapped it. This solution is a slightly (very slightly) easier than shelling out to `make test` and parsing the output since I only needed the percentage of tests that fail. Besides, I was curious if it would work. To repeat: very ugly kludge for demonstration purposes only. If you truly, deeply, and sincerely need to do this sort of thing, look at Test::Harness::Straps which can run everything for you and hand you back the information. I haven't done that yet because I've been little-l lazy (or big b Busy). -- brian d foy <bdfoy@cpan.org>	[reply] [d/l]
Re: redirecting output from a format by Flame (Deacon) on Nov 29, 2004 at 23:33 UTC
Sorry, it's a well known fact that you can't use IO::String to redirect format calls. format and IO::String As you can see there, I've tried it in the past. My code doesn't have bugs, it just develops random features. Flame	[reply]
Re: redirecting output from a format by ysth (Canon) on Nov 30, 2004 at 07:15 UTC
You can't use IO::Scalar, but you can use PerlIO::scalar in 5.8.x: `format FOO= @\|\|\| @\|\|\| @\|\|\| $x,$y,$z . $x=1;$y=2;$z=3; $save = ""; open FOO, ">", \$save; write FOO; print "got:$save!\n";` [download] Reopening STDOUT is a little more complicated, but easily doable.	[reply] [d/l]
Re: redirecting output from a format by jZed (Prior) on Nov 29, 2004 at 21:40 UTC
You need to tie STDERR to a scalar also.	[reply]
Re^2: redirecting output from a format by mpeters (Chaplain) on Nov 29, 2004 at 21:57 UTC
I did try that in my initial experimentation, and I revisited it again after your suggestion, but still no dice... after I redirected STDERR to a scalar I ended up with nothing there. I did this: `my $test_output; my $test_err; tie(STDOUT, 'IO::Scalar', \$test_output); tie(STDERR, 'IO::Scalar', \$test_err); eval { runtests(@testfiles); }; $test_output .= $@ if ($@); untie(STDOUT); untie(STDERR); $test_output .= $test_err;` [download] $test_output was no different than it was before. No failed test report.	[reply] [d/l]
Re: redirecting output from a format by petdance (Parson) on Nov 30, 2004 at 05:20 UTC
Why do you want the output from Test::Harness in a scalar? What do you plan to do with it? xoxo, Andy	[reply]
Re^2: redirecting output from a format by mpeters (Chaplain) on Dec 02, 2004 at 18:23 UTC
I'm trying to capture it and send it in an email... automated build with an accompanying test whose results are sent to the development team	[reply]
Re^3: redirecting output from a format by petdance (Parson) on Dec 02, 2004 at 19:49 UTC
So why bother capturing runtests()? Catch the output of make test or prove. Here's the smokebot that we use. At some point I should put it into Test::Harness proper. #!/bin/sh if [ $# -lt 2 ] then echo Must pass at least a branch, and one email address,. echo plus any parms to echo pass to smoke. exit 1 fi BRANCH=$1 shift MAIL=$1 shift cd $TMP DIR=tw FULLPATH=$TMP/$DIR # This assumes you have already logged in once as anoncvs # so that the password is in your ~/.cvspass file. #cvs -d/home/cvs -Q co -d $DIR -r $REV tw > /dev/null svn co file:///home/svn/tw/$BRANCH $DIR > /dev/null TWROOT=$FULLPATH export TWROOT /home/smoke/tw/Dev/devapache stop > /dev/null 2>&1 /home/smoke/tw/Dev/devapache start > /home/smoke/smoke.out 2>&1. cd $TWROOT smoke $@ >> /home/smoke/smoke.out 2>&1. grep -i "^Failed" /home/smoke/smoke.out > /home/smoke/smoke.out.fail if [ -s /home/smoke/smoke.out.fail ] then STATUS="FAILED" mail -s"Smoke $REV $@ $STATUS `date`" $MAIL < /home/smoke/smoke.ou +t else STATUS="passed" fi /home/smoke/tw/Dev/devapache stop >> /home/smoke/smoke.out 2>&1. [download] Note that smoke is an early predecessor to prove, so modify for your tastes. xoxo, Andy	[reply] [d/l]