unixawksubstr

Get last field using awk substr


I am trying to use awk to get the name of a file given the absolute path to the file.
For example, when given the input path /home/parent/child/filename I would like to get filename I have tried:

awk -F "/" '{print $5}' input

which works perfectly.
However, I am hard coding $5 which would be incorrect if my input has the following structure:

/home/parent/child1/child2/filename

So a generic solution requires always taking the last field (which will be the filename).

Is there a simple way to do this with the awk substr function?


Solution

  • Use the fact that awk splits the lines in fields based on a field separator, that you can define. Hence, defining the field separator to / you can say:

    awk -F "/" '{print $NF}' input
    

    as NF refers to the number of fields of the current record, printing $NF means printing the last one.

    So given a file like this:

    /home/parent/child1/child2/child3/filename
    /home/parent/child1/child2/filename
    /home/parent/child1/filename
    

    This would be the output:

    $ awk -F"/" '{print $NF}' file
    filename
    filename
    filename