How can you find unique lines or duplicate lines in a file based on the content of the first field, or the first n characters ?
The uniq command on OS X lacks the
-w switch that is available under Linux:
-w, --check-chars=N : compare no more than N characters in lines, which solves the problem.
Can it be done without reimplementing
uniq in awk ?
The number of fields is not constant. I would like to use only default tools installed on OS X. I use Macports a lot, but in this case, I don't want to use them.