[PLUG] An obscure (at least to me) useful tool

[brooks at netgate.net]

If you use vi, a simple ":set nu" will also provide line numbers. How many 
other (simple) ways are there to number lines in a file? You'd think UNIX 
tool designers were BASIC programmers :-). BASIC...

   10 print "hello world"
   20 goto 10

Those were simpler times.

But I digress. Getting back to the topic. Why do we need a "cat -n" and an 
"nl"? Feature bloat seems to creep into even simple UNIX utilities.

And here are a couple of more goods ways of finding a line number using 
sed or grep and a pattern:

   sed -n /"easily"/'{=;p;}' < data_analysis.txt
   34
            I could easily implement netblock blocking in using an

   grep -n "easily" data_analysis.txt
   34:        I could easily implement netblock blocking using an

Or use grep to label all the lines with numbers:

   grep -n "^.*$" data_analysis.txt

We're lucky to have so many tools in the toolbox.

> When I was learning linux more than 20 years ago Eric Harrison explained it
> to me: "Linux is easy because it has very simple tools, each doing only one
> thing well. However, there are thousands of little tools."