johnny

I "graded" myself ahead of time, while I'm reading the chapter I thought I would post some things I thought where interesting:

• double bracket if tests enable regular expression testing: I see this all the time in scripts online but I don't think many script writers understand the implications of double brackets compared to single brackets.

• expressions inside parentheses that evaluate to a nonzero status will return a 0, a zero result from an expression returns a 1. Code like C or Java and while still operates correctly even though in bash exit status's are opposite of boolean values (1 is boolean true but exit status of error, 0 is boolean false but exit status of OK)

done.

Discussion in 4.8.3 has a nice one-liner for running a command and verbosely exiting if it fails: cmd || { printf "%b" "FAILED.\n" ; exit 1 ; }

set -e could also be interesting, but I have typically wrapped most if not all of my commands in 'if' or 'while' loops which negates the effect.

Pacing in this chapter is pretty much crap, in 3.6 the author really drops a load on the reader. But the select function is really cool!

All done... (better late then never). The crazy file redirection was new to me e.g. 3>&1 1>&2 2>&3.