how to do a simple check

[JS]

I have a program called depstats.pl

which takes some files as input so I run it like:

../deptstats file1 file2 file3

and then loop through all those files using the construct:

while(<>)

How do I check if any files were supplied? Because if I just do :

../depstats.pl

the programs never ends until I CTRL-C it.

Thanks for the help.

JS.

 

[Gunnar Hjalmarsson]

All of the script's arguments are stored in the special array
@ARGV, so you can simply make sure it's not empty.

Or maybe:

if (-e $ARGV[0])

 

[JS]

All of the script's arguments are stored in the special array
@ARGV, so you can simply make sure it's not empty.

Or maybe:

if (-e $ARGV[0])

Thanks for your help,

This worked:

usage() if ! $ARGV[0] ;

 

[Tore Aursand]

This worked:

usage() if ! $ARGV[0] ;

There's always more than one way to do it, but please write

usage() unless ( $ARGV[0] );

instead. That 'if !' is ugly, IMO.


--
Tore Aursand <[email protected]>

"Whenever I see an old lady slip and fall on a wet sidewalk, my first
instinct is to laugh. But then I think, what if I was an ant, and she
fell on me. Then it wouldn't seem quite so funny." -- Jack Handey

 

[Helgi Briem]

Thanks for your help,
This worked:
usage() if ! $ARGV[0] ;

Or

usage() unless @ARGV;

which seems a bit easier on the eye.

I use:

die $usage if not @ARGV;

but in the end it's a matter of taste.

 

[Gunnar Hjalmarsson]

if (-e $ARGV[0])

Thanks for your help,

This worked:

usage() if ! $ARGV[0] ;

Okay. Note that my suggestion includes a check of the file path. Only
you know if such a check would be useful.

 

[Tad McClellan]

I have a program called depstats.pl

which takes some files as input so I run it like:

./deptstats file1 file2 file3

and then loop through all those files using the construct:

while(<>)

How do I check if any files were supplied?


Because if I just do :

./depstats.pl

the programs never ends until I CTRL-C it.

That is what <> is _supposed_ to do.

It is waiting for you to provide the input via the keyboard (STDIN).

Try typing some input, then mark the end of input with
a CTRL-D (CTRL-Z on Windows).