in reply to STDIN & STDOUT on Win32 ?
If you have AS perl and/or their htmlized docset, then this is mentioned under the heading STDIN and STDOUT, and Piping don't always work on NT..
Although for my taste it doesn't explain the cause well or offer all the solutions.
If you want your program to be able to accept input from the command line or from a file specified on the command line, is to use the 'diamond operator' <> instead of <STDIN>:
C:\test>type junk1.pl #! perl -slw use strict; print "?$_?" for <>; C:\test>junk1 hello world ^Z ?hello world ? C:\test>junk1 junk1.pl ?#! perl -slw ? ?use strict; ? ?print "?$_?" for <>; ?
However, that won't work for piping like this:
C:\test>type junk1.pl|junk1 The process tried to write to a nonexistent pipe.
Instead you have to use
C:\test>type junk1.pl | perl junk1.pl ?#! perl -slw ? ?use strict; ? ?print "?$_?" for <>; ?
or use the AS solution, pl2bat(.bat) which can be found in x:\yourperl\bin, (assuming you have AS perl :)
What that does, is wrap yourscript.pl in some batch code and outputs it as yourscript.bat, which then allows you to use both
yourscript <file and
type file | yourscript syntaxes without decoration:
C:\test>pl2bat junk1.pl C:\test>type junk1.bat @rem = '--*-Perl-*-- @echo off if "%OS%" == "Windows_NT" goto WinNT perl -x -S "%0" %1 %2 %3 %4 %5 %6 %7 %8 %9 goto endofperl :WinNT perl -x -S %0 %* if NOT "%COMSPEC%" == "%SystemRoot%\system32\cmd.exe" goto endofperl if %errorlevel% == 9009 echo You do not have Perl in your PATH. if errorlevel 1 goto script_failed_so_exit_with_non_zero_val 2>nul goto endofperl @rem '; #! perl -slw #line 15 use strict; print "?$_?" for <>; __END__ :endofperl C:\test>junk1 <junk1.pl ?#! perl -slw ? ?use strict; ? ?print "?$_?" for <>; ? C:\test>type junk1.pl | junk1 ?#! perl -slw ? ?use strict; ? ?print "?$_?" for <>; ?
The downside of this is that if you edit yourscript.pl the changes do not get reflected into yourscript.bat unless you re-run the pl2bat. Which will give you a moment or twos pause for thought if you've forgotten that you converted a script to a .bat and you find that your edits to it don't seem to make any difference!