perl - How to make regex accept strings with a dot -

i'm debugging perl script , encountered errors described in following sections below:

in script, have -td variable designed accept string 1n, 5n, 0.3n, 0.8n

but when try use the last 2 said list, script not work intended, , works fine when use first 2 list.

to give overview, have written portions of script, after code, state concern:

if (scalar(@argv) < 1){ &get_usage() }; # getoptions setup ## getoptions (   'h|help'          => \$help,   'v|version'       => \$version,   'i|input=s'       => \$input,   'o|output=s'      => \$output,     ...  # more options here    'td=s'          => \$td_val, # line in question   'val=s'         => \$v_var,     ...  # more options here  ) or die get_usage();  # call usage of script or     ...  # more codes here  get_input_arg();   # function validate entries user had inputted  #assigning placeholder value creating new file $td_char="\ttd=$td_val" if $td_val; $td_char=" " if !$td_val;  ... # fast forward ...  sub get_input_arg{  ... # here go, there wrong in following regex accept values such 0.8n  unless (($td_val=~/^\d+(m|u|n|p)s$/)||($td_val=~/^\d+(m|u|n|p|s)$/)||($td_val=~/^\d+$/)){# print "\n-td error!\nenter required value!\n"; get_usage();  ... # more functions here ...  } 

for explanation:

1. on console user input -td 5n
2. the 5n assigned td_val , td_char , used printing later
3. this 5n validated get_input_arg() function pass regex unless line.

for 5n input, script work intended, when use -td 0.8n, after validating it, print error message after unless line on console

i know regex failing on matching regards using 0.8n td input, don't know how can fix it. in advance!

you can use

unless (($td_val=~/^\d+(\.\d+)?[munp]s$/)||($td_val=~/^\d+(\.\d+)?[munps]$/)||($td_val=~/^\d+(\.\d+)?$/)) 

explanation:

your regex has \d+ matches integers.. replace \d+(\.\d+)? (integral part followed optional decimal part)

see demo