Removing phone numbers from a file

[ianicr]

Has anyone got any ideas how I can get phone numbers out of a file? The file in question is a complete mess! fields all over the place etc.. Is there a way to just take out the phone numbers a put them into a newline seperated file?
eg.
02081234567
01422486789

Thanks

 

[Ygor]

This will extract 11-digit numbers...

awk 'match($0,"[0-9]{11}&quot{print substr($0,RSTART,RLENGTH)}' $FILE