return codes are always zero

[m-fonseca]

: netmask --version
netmask, version 2.4.4

: netmask asdf
netmask: parse error "
: echo $?
0

All errors have a zero return code. This makes it less then ideal for scripting.

thus

: netmask 192.168.1.255 && echo "valid address" 
  192.168.1.255/32
valid address

&

: netmask 192.168.1.256 && echo "valid address" 
netmask: parse error "192.168.1.256": Invalid argument
valid address

are both 'valid addresses'

[tlby]

This is a good argument for promoting this warning to an error. Thank you for pointing it out.

[tlby]

I will point out that if the goal is to use this tool purely to do address validation, I'd recommend using a different strategy. perhaps something like:

: perl -MSocket -le 'exit(not Socket::inet_pton AF_INET(), $ARGV[0])' 192.168.1.255 && echo "valid address"
valid address

vs.

: perl -MSocket -le 'exit(not Socket::inet_pton AF_INET(), $ARGV[0])' 192.168.1.256 && echo "valid address"

could be used for that purpose.

Nevertheless, this tool should consider bad input a fatal rather than a warning.