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Issue with Grep Posted by mescorpion (mescorpion), 17 June 2005 Hii am trying to findout blank lines in a file... using grep... grep -n "^$" filename will work fine... but what if there are blank spaces are tabs... so i modified the my pattern to say: grep -n "^[ \t]*$" filename but this is not working... any suggestions...what should be the reg exp... even "^[ ]*$" is working fine and able to findout lines with blank spaces.. but \t is not working... please suggest... one more quest... is there any way which can count the number of occurences of the pattern... grep -c will count the number of lines containing pattern rather than counting how many times it occurred... Posted by admin (Graham Ellis), 17 June 2005 You're in the Perl forum ... but you're asking a question about the command line "grep" utility of Unix and / or Linux, right? ((Just asking for a confirmation because there's also a grep built in to Perl! ))On the command line ... firstly, I would use single quotes rather than double quotes around the regular expression. That way, you'll be able to get all your special character sequences through to grep rather than have the shell deal with some of the special characters. I would write egrep '^[[:space:]]*$' filename on the system I'm using today to allow for any combination of white spaces to make up the blank line, and also I find that form more readable. Count of occurrences rather than lines ... write a Perl program: #!/usr/bin/perl -n $c++ while(/abcd/g); BEGIN { print $c; } should do it (looking for "abcd" in files named on the command line) Posted by mescorpion (mescorpion), 17 June 2005 Hithanks sorry... i didnt find any UNIX or Linux forum thread here... so just posted in this section... This page is a thread posted to the opentalk forum
at www.opentalk.org.uk and
archived here for reference. To jump to the archive index please
follow this link.
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