| Subject: | Suggested policy: avoid builtin glob() except for simple cases |
Most perl programmers who use the builtin glob() function are unaware
that it has funny behaviour when given spaces.
glob('*.c *.h')
will return filenames matching *.c and then those matching *.h. (It is
possible for the same filename to appear twice.)
I believe this was originally a side-effect of running an external tcsh
for globbing, and was kept for compatibility. In the above example this
behaviour looks benign and even useful. Nobody would write a glob
pattern like that unless they wanted to match two different wildcards.
However, nowadays filenames with spaces in them are not uncommon. Code
like the following
my $dir = get_directory();
my @files = glob "$dir/*.txt";
contains a bug: it will break whenever $dir contains spaces. That is
probably not what the programmer intended.
To be safe you should use File::Glob::bsd_glob. I suggest a policy to
forbid builtin glob and recommend bsd_glob instead.
But then, there is nothing buggy or unsafe about glob('*.c'). To avoid
too much nagging from perlcritic, the policy should make an exception if
the argument to glob is a constant string.