Funky file writing -- betcha you can't figure this one out 1

[Nebbish]

I'm stumped (again):

open(OUTPUT, "> tester.txt");
print OUTPUT "hello\n";

open(STDERR, "> tester.txt");
die "123456789ThisIsMyErrorMessage";

This produces a file containing the following:

hello
89ThisIsMyErrorMessage at C:\ProjectsListExport\Scripts-7-15-04\webExporterModules\printLog.pm line 9.

No, I didn't leave out the 1-7 by accident--it's really not there. Fooling around with buffering ($| = 1) doesn't help. Where did the rest of my error message go?

-Nick

 

[MikeLacey]

Try this -

open(OUTPUT, "> tester.txt");
print OUTPUT "hello\n";
open(STDERR, ">&OUTPUT");

die "123456789ThisIsMyErrorMessage";

It makes STDERR a duplicate of OUTPUT

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[Nebbish]

It works (and I'll use it, thank you), but why didn't my original code work?

 

[columb]

I'm no perl guru but I don't think the underlying OS will like the fact that you opened tester.txt twice. With I/O buffering who knows wher the seven chars went!


Columb Healy
Living with a seeker after the truth is infinitely preferable to living with one who thinks they've found it.

 

[MikeLacey]

columb is quite right, you can't open a file twice - you have to duplicate the file handle.

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[columb]

And another quick thought
seven chars = hello\r\n if your OS is windows based, if you're *nix or Mac then that theory goes out of the window

Columb Healy
Living with a seeker after the truth is infinitely preferable to living with one who thinks they've found it.

 

[Nebbish]

Still isn't quite working. The buffering appears to be off:

$| = 1;

open(OUTPUT, "> tester.txt");
open(STDERR, ">&OUTPUT");

print OUTPUT "Here is my first statement.\n";
die "Second statement";

Produces

Second statement at C:\ProjectsListExport\Scripts-7-15-04\webExporterModules\printLog.pm line 9.
Here is my first statement.

Note that buffering is turned off ($| = 1), but the death happens before the print. Hmmmmmm.....ideas?

-Nick

 

[MikeLacey]

you're not select ing the filehandle before you turn off buffering so the "buffering" setting is probably applying to STDOUT, also - try setting $| after you dupe the filehandle.

so after the two open lines

select OUTPUT; $|=1;

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[Nebbish]

I had never seen select before, that did the trick. I kind of assumed $| affected the buffering for all filehandles. Good to know it doesn't.

Thanks,

Nick