Most powerful examples of Unix commands or scripts every programmer should know

Question

There are many things that all programmers should know, but I am particularly interested in the Unix/Linux commands that we should all know. For accomplishing tasks that we may

Answer 1

Your shell is the most powerful tool you have available

1. being able to write simple loops etc
2. understanding file globbing (e.g. *.java etc.)
3. being able to put together commands via pipes, subshells. redirection etc.

Having that level of shell knowledge allows you to do enormous amounts on the command line, without having to record info via temporary text files, copy/paste etc., and to leverage off the huge number of utility programs that permit slicing/dicing of data.

Unix Power Tools will show you so much of this. Every time I open my copy I find something new.