ActiveState Community Site - print function and chr(13) terminator - Comments

explanation

MarcZ — Thu, 10 Jan 2008 18:34:15 +0000

use binmode on the output file, then add your own end of line character ?

Copied from the ActivePerl Documentation:

On Win32 platforms, there's a big difference between text files and binary files. For text files, the \r\n characters are translated into \n when read from disk, and the ^Z character is read as an end-of-file marker. For binary files, no such translation is used.

Although this works great for text files, it really messes things up when you're trying to read and write binary files. If the read or write does not abort prematurely because a ^Z was found in the file, you will almost definitely get incorrect bytes in the file due to \n -> \r\n translation.

The problem is that ActivePerl, and the C runtime library it uses, open file in text mode by default. For each file handle you use in Perl for binary data, you need to specify that the file handle is in binary mode. Fortunately, there's a function, binmode, that does just that. See the perlfunc documentation file for details.

This script copies one binary file to another. Note its use of binmode to set the mode of the file handle.

open( INFILE, "<$infile" );
    open( OUTFILE, ">$outfile" );
    
    binmode( INFILE ); binmode( OUTFILE ); # crucial for binary files!
    
    while ( read( INFILE, $buffer, 1024 ) ) {
        print OUTFILE $buffer;
    }
    
    close( INFILE ); 
    close( OUTFILE );

workaround

prophet_5 — Thu, 10 Jan 2008 16:40:57 +0000

I found 1 workaround, but it's not elegant.

I ran the output file through dos2unix, which fixed the format issue.

This is really a workaround, not a solution (but I'll use it if that's all that I can do.

re: chr(13)

prophet_5 — Thu, 10 Jan 2008 16:39:33 +0000

I used chomp() to strip off the line terminator, but after I manipulate the data, I write it to another file, and it automatically appended chr(13) on the end of each print() statement, regardless of if I added a \n or not.

Is there a way to suppress the chr(13) addition?

Is it from your input data

MarcZ — Thu, 10 Jan 2008 16:35:57 +0000

Is it from your input data ?

the function chomp could be used to remove the last character.

if not, please give us a small program example...

print function and chr(13) terminator

prophet_5 — Mon, 07 Jan 2008 21:40:42 +0000

I am trying to write text to a file using the "print" function.

When I try to write (print) data, the print function is appending a non-printing character (13) to the end of each line. I need to supress this, or change it to (13)(10), as it is making the file unreadable to other software.

Is this a bug in 5.8.8, or an expected behavior? Can I alter this behavior?

Thanks in advance,

Dave