tying STDIN/STDOUT
I know this has been discussed a little before, but the Test.pm
PerlHandler I've attached does not work as expected. The reason being
that dup-ing a read filehandle to STDIN overwrote STDOUT instead (well,
actually both, since apache apparently uses the same handle for
input and output). Anyway, this actually worked in RH 6.x, but stopped
working when I installed 7.1. My guess is that for whatever versions are
in 6.x STDIN and STDOUT were only tied for registry scripts, but in 7.x
they got tied for regular content handlers as well.
Currently, I'm working around it by putting
untie(*STDIN);
untie(*STDOUT);
at the beginning of my handler. Is that the best way to go? I tried
sticking it in the initialization part of the module, but that didn't
work. Why is that?
Anyway, if anyone has additional questions about what I'm doing here, let
me know. The example is quite contrived, but it does affect a real-world
situation.
The actual problem line is open(STDIN, RD), which dups RD onto
filehandle 1 (STDOUT) instead of 0 (STDIN). Later, when '/bin/ls' is
exec-d, when it tries to write to STDOUT, it gets EBADF because there's a
read file handle there.
Anyway, the script can be installed with
PerlRequire Test.pm
location /mytest/
SetHandler perl-script
PerlHandler WRI::Test::handler
/location
Anyway, let me know if there is a better way of handling the situation.
Jon
--
PGP information is available at http://members.wri.com/johnnyb/about/
package WRI::Test;
sub handler
{
my $r = shift;
my $testfh;
my $line;
$r-send_http_header('text/html');
$r-print(EOF);
html
head
title
My Test Page
/title
/head
body
pre
EOF
$testfh = runtest();
while($line = $testfh)
{
$r-print($line);
}
$r-print(EOF);
/pre
/body
/html
EOF
return OK;
}
sub runtest
{
pipe(RD, WR);
unless(open(MYHANDLE, -|))
{
close(WR);
open(STDIN, RD);
exec('/bin/ls');
}
close(RD);
close(WR);
return \*MYHANDLE;
}
1;
Re: tying STDIN/STDOUT
hmm... i think i have a similar question. i want to prevent people from writing data directly to the apache connection and instead force them to use an object i provide for generating output. they can call $obj-print() directly, but i also want them to be able to use 'print foo\n' as is standard in handlers and registry scripts. seems like i want to untie STDIN and STDOUT as per below.. but then how do i attach those handles to my object's print method? is tieing the correct approach, or is there some other kind of filehandle magic i can use? On Fri, 13 Jul 2001, Jonathan Bartlett wrote: I know this has been discussed a little before, but the Test.pm PerlHandler I've attached does not work as expected. The reason being that dup-ing a read filehandle to STDIN overwrote STDOUT instead (well, actually both, since apache apparently uses the same handle for input and output). Anyway, this actually worked in RH 6.x, but stopped working when I installed 7.1. My guess is that for whatever versions are in 6.x STDIN and STDOUT were only tied for registry scripts, but in 7.x they got tied for regular content handlers as well. Currently, I'm working around it by putting untie(*STDIN); untie(*STDOUT); at the beginning of my handler. Is that the best way to go? I tried sticking it in the initialization part of the module, but that didn't work. Why is that? Anyway, if anyone has additional questions about what I'm doing here, let me know. The example is quite contrived, but it does affect a real-world situation. The actual problem line is open(STDIN, RD), which dups RD onto filehandle 1 (STDOUT) instead of 0 (STDIN). Later, when '/bin/ls' is exec-d, when it tries to write to STDOUT, it gets EBADF because there's a read file handle there. Anyway, the script can be installed with PerlRequire Test.pm location /mytest/ SetHandler perl-script PerlHandler WRI::Test::handler /location Anyway, let me know if there is a better way of handling the situation. Jon
Re: tying STDIN/STDOUT
[EMAIL PROTECTED] (brian moseley) wrote: hmm... i think i have a similar question. i want to prevent people from writing data directly to the apache connection and instead force them to use an object i provide for generating output. they can call $obj-print() directly, but i also want them to be able to use 'print foo\n' as is standard in handlers and registry scripts. seems like i want to untie STDIN and STDOUT as per below.. but then how do i attach those handles to my object's print method? is tieing the correct approach, or is there some other kind of filehandle magic i can use? Tying is probably the way to go. You can check out Apache::Filter for an example of how to tie STDOUT. ------ Ken Williams Last Bastion of Euclidity [EMAIL PROTECTED]The Math Forum
