Question

I’m writing a script that will fold, sort and count text in a file. I need to design the program so that, if it is given multiple filenames on the command line, it processes each one separately, one after the other. I think I could write a loop but I don’t know that much about those yet so if possible would like to try other options. Are there other options that I can add to this so more than one file name can be entered in the command line?

if test $# -lt 1
then
echo “usage: $0 Enter at least one DNA filename”
exit
fi
if test -r $*
then
fold -w3 $* | sort | uniq -c | sort -k1,1nr -k2
else
echo “usage: $* must be readable”
exit
fi

Nena

Answer 1

for loop will be appropriate here. The following form is used to iterate over positional arguments:

for f; do
   # do work here using "$f" as the current argument
done

This is equivalent to a more verbose version:

for f in "$@"; do
   # do work here using "$f" as the current argument
done