perlquestion
jarich
<p>
I teach Perl to programmers using both *nix and Windows operating systems. One of the suggestions I give them is to use <code>File::Temp</code> for temporary files. It's a great module, especially because it's standard so everyone will already have it.
</p>
<p>
Unfortunately, I've just discovered that File::Temp doesn't exactly do what I want it to. When my students using *nix open temporary text files, everything just works. When my students using Windows open temporary text files, their newlines (\n) are not correctly translated into crlf.
</p>
<p>
[John M. Dlugosz] touched on the problem a couple of years ago in [Why does File::Temp use sysopen?] but he was blaming the wrong cause. File::Temp uses binmode (or an equivalent) if it can. It says so in the [cpan://File::Temp|documentation].
</p>
<blockquote>
<p><b>BINMODE</b></p>
<p>
The file returned by File::Temp will have been opened in binary mode if such a mode is available. If that is not correct, use the binmode() function to change the mode of the filehandle.
</p>
<p>
Note that you can modify the encoding of a file opened by File::Temp also by using binmode().
</p>
</blockquote>
<p>
The [perldoc://binmode|binmode documentation] says:
</p>
<blockquote>
<p>
For the sake of portability it is a good idea to always
use it when appropriate, and to never use it when it isn't
appropriate.
</p>
</blockquote>
<p>
I realise I can "fix" File::Temp's use of binmode for text files by calling binmode:
</p>
<code>
my ($tmp_fh, $tmp_name) = tempfile();
binmode($tmp_fh, ":crlf" );
</code>
<p>
but I don't want to teach that. I want an easy, 100% portable way of doing it. I want my students to be able to write exactly the same code on either system and have it work - even for text files.
</p>
<p>
Am I missing an easier way of doing this?
</p>