In order to extend my ‘grep’ emulator in Perl I have added support for a -r switch which enables recursive searching in sub-directories. Now the command line invocation looks something like this:
perl pgrep.pl -r <directory> <expression> Both -r and the directory arguments are optional (directory defaults to ‘.’). As of now I simply check if the first argument is -r and if yes set the appropriate flag, and scan in the rest two arguments using the shift operation. This obviously would be a problem if -r were to appear at the end of the argument list or worse still – in between the directory name and the search expression.
One workaround would be to simply delete the -r item from the @ARGV array so that I can simply shift-in the remaining arguments, but I can’t figure out a way to do it without getting an ‘undef’ in an odd position in my array. Any suggestions or different strategies that you might have used are welcome.
You should be using
GetOpt::Long. This will do everything you need as described.