Hi,

Last question:
you may start with 'Linux Hands on Guide', you can find it on tldp.org; it's not specifically about shell scripting, but has useful exercises at the end of each chapter that may be useful for you.

see ya
fra


---------- Post updated at 14:55 ---------- Previous update was at 14:55 ----------

Answer to first question:
$i gets the value of the first word (that is, set of contiguous, non space-interleaved characters) in the file.
in order to loop you don't have to modify $i. $i in the specific example is not a counter.

Second question: it' not very clear to me what are the starting conditions (what are the input data or files).