Match decimal numbers

Question

I would like to match decimal numbers like:

0.0
0.12
1.00
1.12
-0.123
-1.000
-1.123

without matching negative zeros: -0.0 or -0.00, -0.000 etc.

I have no idea how to extend the /^-?[0-9]+\.[0-9]+$/ regex to not to allow negative zeros.

UPDATE:

• No leading zeros allowed: 01.1 or -01.1
• Whole and fractional characters are required (.5 or 5. not allowed)

Answer 1

IIUC, you just need to add a negative lookahead (?!-0\.0+$):

^(?!-0\.0+$)-?\d+\.\d+$

Example:

echo '0.0
0.12
1.00
1.12
-0.123
-1.000
-1.123
-0.00
-0.0
-0.000010
-12.34
' | perl -lne 'print if /^(?!-0\.0+$)-?\d+\.\d+$/'
#0.0
#0.12
#1.00
#1.12
#-0.123
#-1.000
#-1.123
#-0.000010
#-12.34