in reply to perl wkhtmltopdf Error: Unable to write to destination

'|-' means open a command and pipe data to it, & the help for open says :-

You are not allowed to "open" to a command that pipes both in and out,
+ but see
       IPC::Open2, IPC::Open3,...

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So it's no great surprise that it doesn't work.

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Re^2: perl wkhtmltopdf Error: Unable to write to destination
by djlerman (Beadle) on May 07, 2014 at 18:22 UTC

    Thank you for your response.

    I will try it with IPC::Open3.

    I'm trying to create a simple example for IPC::Open3. Should I create a separate post relating to getting Open3 to work?

    Below is code I am trying and here is the output I get:

    OUTPUT: 
    err-> /bin/ls: write error: Bad file descriptor retval-> 512

    [download]
    CODE: 
    #!/usr/bin/perl
use warnings;
use strict;
use IPC::Open3;

print "Content-type: text/html\n\n";

print ' <!DOCTYPE HTML>
        <html lang="en">
        <head>
          <title>IPC::Open3 Example</title>
        </head>
        <body>';

        
my $cmd = '/bin/ls -la';

my $pid = open3(\*WRITER, \*READER, \*ERROR, $cmd);

while( my $output = <READER> ) {
  print "output-> $output\n";
}

while(my $errout = <ERROR> ) {
  print "err-> $errout\n";
}

waitpid($pid, 0 ) or die "$!\n";
my $retval =  $?;
print "retval-> $retval\n";

print " </body>
        </html>";

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[d/l]
[select]

      Here is the final working solution I came up with. If there is anything I missed please let me know. I don't know if I am using "gensym()" correctly. The main thing that was an issue was rights on the server side.

      #!/usr/bin/perl
use warnings;
use strict;
use IPC::Open3;
use Symbol;

my $cmd = '/usr/local/bin/wkhtmltopdf - -';

my $err = gensym(); 
my $in  = gensym();
my $out = gensym();

my $pdf = '';

my $pid = open3($in, $out, $err, $cmd)  or die "could not run cmd : $c
+md : $!\n";

my $string = '<html><head></head><body>Hello World!!!<br /><br /><br /
+>
IMG: <img id="image" src="data:image/gif;base64,R0lGODlhFwAPAKEAAP///w
+AAAMzMzLi3tywAAAAAFwAPAAACQIyPqQjtD98RIVpJ66g3hgEYDdVhjThyXSA4aLq2rgp
+78hxlyY0/ICAIBhu/HrEEKIZUyk4R1Sz9RFEkaIHNFgAAOw==" />
</body></html>';

print $in $string;
close($in);

while( <$out> ) {
  $pdf .= $_
}

# for trouble shooting
while( <$err> ) {
  # print "err-> $_<br />\n";
}

# for trouble shooting
waitpid($pid, 0 ) or die "$!\n";
my $retval =  $?;
# print "retval-> $retval<br />\n";

print "Content-Disposition: attachment; filename='testPDF.pdf'\n";
print "Content-type: application/octet-stream\n\n";
print $pdf;

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