This regex ^[-+]?[0-9]+\.?[0-9]*$
will match only digits with an optional .
:
$ echo 30 | grep -Eq '^[-+]?[0-9]+\.?[0-9]*$' && echo Match
Match
$ echo 30.10 | grep -Eq '^[-+]?[0-9]+\.?[0-9]*$' && echo Match
Match
$ echo 30. | grep -Eq '^[-+]?[0-9]+\.?[0-9]*$' && echo Match
Match
$ echo +30 | grep -Eq '^[-+]?[0-9]+\.?[0-9]*$' && echo Match
Match
$ echo -30 | grep -Eq '^[-+]?[0-9]+\.?[0-9]*$' && echo Match
Match
I think when you tried ^*[0-9]
you wanted ^[0-9]*
Rexeplanation:
^ # Match start of string
[-+]? # Match a leading + or - (optional)
[0-9]+ # Match one or more digit
\.? # Match a literal . (optional, escaped)
[0-9]* # Match zero or more digits
$ # Match the end of the string
Note: this matches numbers followed by a .
like 30.
, not sure if this is acceptable for you.
Edit: Don't quote the regex
testNo=30.00
if [[ $testNo =~ ^[+-]?[0-9]+\.?[0-9]*$ ]]; then
echo Match
fi
>>> Match