Regex matching a integer in a line

[dptom79]

Hi experts,
Can anyone tell me a regex to see if the line has a numeral only i.e,
I dont want the integer in a line. I want the line which has only an
integer while I am parsing a file..there will be many lines with
integers but I want the line with ONLY integer in it (with some
whitespaces which are to be avoided) and nothing else.
Please help
Thanks in advance
Tom

 

[Martijn Lievaart]

Hi experts,
Can anyone tell me a regex to see if the line has a numeral only i.e,
I dont want the integer in a line. I want the line which has only an
integer while I am parsing a file..there will be many lines with
integers but I want the line with ONLY integer in it (with some
whitespaces which are to be avoided) and nothing else.

/^[\s\d]+$/

HTH,
M4

 

[Iain Chalmers]

Hi experts,
Can anyone tell me a regex to see if the line has a numeral only i.e,
I dont want the integer in a line. I want the line which has only an
integer while I am parsing a file..there will be many lines with
integers but I want the line with ONLY integer in it (with some
whitespaces which are to be avoided) and nothing else.

/^[\s\d]+$/

Ummm... I don't think so:

bigiain% perl -e'$_="1 2 3";print "OK\n" if /^[\s\d]+$/'
OK

how about

/^\s*[\d]+\s*$/

and

/^\s*([\d]+)\s*$/

if you want to capture the digits only.

(extending to deal with negative integers left as an exercise for the
reader)

big

 

[Josef Moellers]

Hi experts,
Can anyone tell me a regex to see if the line has a numeral only i.e,
I dont want the integer in a line. I want the line which has only an
integer while I am parsing a file..there will be many lines with
integers but I want the line with ONLY integer in it (with some
whitespaces which are to be avoided) and nothing else.

/^[\s\d]+$/

That will match " 1 2 3 ".

If the OP wants single numbers only ("which has only an integer"), this
/^\s*\d+\s*$/
might be more appropriate.