How to check if today is a weekend in bash?

Question

How to check if today is a weekend using bash or even perl?

I want to prevent certain programs to run on a weekend.

Answer 1

Use Perl's localtime operator.

localtime

Converts a time as returned by the time function to a 9-element list with the time analyzed for the local time zone. Typically used as follows:

#  0    1    2     3     4    5     6     7     8
($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);

…

$wday is the day of the week, with 0 indicating Sunday and 3 indicating Wednesday.

For example:

$ date
Sun Aug 15 20:27:29 CDT 2010

$ perl -le 'my $wday = (localtime)[6];
            print $wday >= 1 && $wday <= 5 ? "weekday" : "weekend"'
weekend