Learning Perl on Win32 Systems

Using Pathnames and Filenames

When working with files and pathnames, you’re faced with an interesting choice: what’s the best way of specifying pathnames? Perl accepts either a slash or a backslash as a path delimiter.^[63] The slash is typically used by UNIX systems to delimit paths while the backslash is the traditional MS-DOS path delimiter. The slash is also used as a path delimiter when specifying URLs. The following statements all evaluate to the same thing, as far as Perl is concerned:^[64]

"c:\\temp"    # backslash (escaped for double quoted string)
'c:\temp'     # backslash (single quoted string)
"c:/temp"     # slash - no escape needed

There are a couple of tradeoffs associated with either approach. First we look at the backslash: if you use the backslash to delimit paths, you have compatibilty problems with scripts that need to run on UNIX systems. You also need to remember to escape the backslash inside of double-quoted strings (or use single-quoted strings, because they are not interpolated). Finally, you need to remember to use a slash if you’re outputting URL paths.

If you decide to use a slash, you need to consider the following issues: although some Windows NT programs and utilities accept slashes as a delimiter, many do not. Traditionally, the slash is used to specify command-line options to MS-DOS programs, so many programs interpret slashes as command switches. Generally speaking, if your script is self contained, you won’t run into any difficulties using slashes. However, ...