1.if [ "$1" ]
2.then
3. # save the number of args and first argument in variables.
4. num_args=$#
5. id="$1"
6. echo "$id"
7. #echo "$1" > crapfile.txt
8. echo `sed 's/\*/'\*'/g' < crapfile.txt`
Above is a partial code.I would like to ask:
at line 1: what is $1 how it works
at line 4: what is $#
at line 8: what does it try to do.
I am new to shell programming. Can anyone out there explain it to me. Thanks