Question

I have a data that looks like this:

-1033   -   222 100 -30 - 10 

What I want to do is to capture all the numbers excluding ‘dash only’ entry.

Why my awk below failed?

 awk '$4 != '-' {print $4}' 

Answer 1

Your awk script says

If the fourth field is not a dash, print it out

However, you want to print it out if the line is not a dash

awk '$0 != '-'' 

Default action is to print so no body is needed.

If you want to print group of numbers, you can use a GNU awk extension if you use gawk. It allows splitting records using regular expressions:

gawk 'BEGIN { RS='(^|\n)-($|\n)' } { print 'Numbers:\n' $0 }' 

Now, instead of lines, it takes a group of numbers separated by a line containing only -. Setting the field separator (FS) to a newline allows you to iterate over the numbers within such a group:

gawk 'BEGIN { FS='\n'; RS='(^|\n)-($|\n)' }        { print 'Numbers:'; for(i=1;i<=NF;i++) print ' *: ' $i }' 

However I agree with other answers. If you just want to filter out lines matching some text, grep is the better tool for that.