I can't test since I have no RPI, but Device::BCM2835 seems to export all functions and constants by default.

so please try

gpio_fsel(RPI_V2_GPIO_P1_07, $inputcmd);

alternatively preceded by

use Device::BCM2835 qw/gpio_fsel RPI_V2_GPIO_P1_07 ... etc/;
[download]

or

use Device::BCM2835 ':all';
[download]

This should shorten your code considerably.

The rest of your question is a bit fuzzy, please explain.

probably something like my $pin1 = RPI_V2_GPIO_P1_07 is just what you want?