in reply to Stupid If Question

First, EVEN ON WINDOWS:
#!/usr/bin/perl -w
use strict;

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Windows does NOT care about the path to Perl, BUT it does care about the -w (use warnings). This standard header will work on both Unix and Windows.

Second, This "back-slash" versus "forward-slash" stuff can be a mess! The ANSWER is that Perl has fixed this! Always use Unix "/" for all path names known to Perl. $root = "C:/xyzzy", NOT "C:\\xyzzy"! Perl will translate the "/" to back slash when needed, which relieves you of the problem of having to code "\\path" vs "/path". This "escape char" stuff is a HUGE source of errors and its not needed.

Third, using characters that could have meaning within a print statement (like < or >) can potentially get you into trouble. This is the time for "\", or just using commas to separate tokens: 

print "zip_exe = "<",$zipexe,">\n";
#"<$zipexe>$x" might not parse "right" in the 
#general case although usage in above code appears ok..

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I've seen code before that uses the "." concatenation op instead of just a simple comma. In Perl this is just not necessary. Use "," when you can do so.

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Re^2: Stupid If Question
by ikegami (Patriarch) on Aug 19, 2009 at 03:36 UTC

    Perl will translate the "/" to back slash when needed

    I doubt it since the OS happily accepts "/" as a path separator.

    While the following isn't proof, it would surprise most: 

    C:\Documents and Settings\ikegami>dir "c:/bin"
 Volume in drive C is C
 Volume Serial Number is 28AB-0E8B

 Directory of c:\bin

2008/12/21  10:53 PM    <DIR>          .
2008/12/21  10:53 PM    <DIR>          ..
.
.
.

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[d/l]
      There are differences in MS OS, consider:

      Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Projects>cd /temp
The system cannot find the path specified.

C:\Projects>cd \temp

C:\TEMP>

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      There can be weird things with "\". I am just saying for the most part, use "/" instead of "\\". I think we agree on that!
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[d/l]

        There are differences in MS OS, consider:

        uh no. We're using the same OS. It seems you didn't execute the same command as I did.

        You need to use quotes since a bare "/" denotes an switch. And while some shell commands and utilities accept "/", chdir aka cd isn't one of them.

        Going back to what I said, the OS (WinXP) itself accepts "/" throughout its API. This is how Perl communicates with the OS, so it's free to use "/".

        There can be weird things with "\". I am just saying for the most part, use "/" instead of "\\". I think we agree on that!

        I made a comment on the text I quoted specifically. The advice you give is sound, although I use "\" personally. "/" just looks to weird.

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Re^2: Stupid If Question
by Anonymous Monk on Aug 19, 2009 at 07:05 UTC
    Not even on windows :) 
    #!/usr/bin/perl --
use strict;
use warnings;

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    Get with the times, -w is dead, long live warnings :D
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[d/l]
      Wrong.

      -w shebang option is alive and well at least in Perl 5.10. And yes this is supported on Windows (not the path), but the -w option just like I said.

      Update: For folks that didn't read the previous:

      #!/usr/bin/perl -w
use strict;

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      should be almost like a mantra on Unix or on Windows!
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