how to use substr in awk?

Question

I have strings that look like this

/foo/bar
/foo/bar/1
/foo/bar/baz
/foo/bar/baz/1

I want to be able to chop off the end only if it's a number. For example, /foo/bar stays the same, but /foo/bar/1 becomes /foo/bar

How to I do this in awk?

Answer 1

Using awk, you can try it as:

awk '{sub(/\/[0-9]+$/,"");print}' filename

For your input output comes as:

/foo/bar
/foo/bar
/foo/bar/baz
/foo/bar/baz

If you want to use substr function in awk:

awk '{line=substr($0,1,index($0,/[0-9]/)-2); if(length(line)==0)line=$0; print line}' filename

Using sed, you can do it as:

while read line; do echo $line | sed 's/\/[0-9]\+$//'; done < filename