Shell Programming and Scripting

can you explain what "NR" do ?
and how can i have this part IP[1], IP[1], IP[2] in loop?
i mean if ip file has 200 row, 200 file create and if it has 127 row, 127 file create, it depends on line number of ip file

In awk, NR is the "number of record", i.e. row or line No. Above small script will loop through your input file, creating n files for n lines in file, i.e. FILE1, FILE2, ... FILEn. Did you check? Please consider Don Cragun's hint if your line count exceeds the system parameter OPEN_MAX (getconf OPEN_MAX):

nice job,
is it possible to have thsis logic without awk?
like with source, read, while .... ?

Of course. But it is way less efficient. What be the reason you want / have to avoid awk?

mm im not familiar with awk options, now with this code i have to read more about awk

Which might not be a fault . . . and pay off soon.
Nevertheless, try

Code:

cat -n file | while read NR IP
  do cat <<EOF > FILE$NR
internal=yes
internalip=${IP%/*}
internal.dest:${IP%/*} port=${IP#*/}
EOF
    done

This is not a uuoc (useless use of cat) as it supplies the line Nos and eliminates the necessity of shell arithmetics.

I agree with RudiC that you would find life much easier working problems like this if you take a little time to learn how to use awk. You might also try the following which doesn't need either invocation of cat and just uses shell built-ins:

Code:

NR=0
while IFS=/ read -r ip port
do	NR=$((NR + 1))
	printf 'internal=yes\ninternalip= %s\ninternal.dest: %s port=%s\n' \
	    "$ip" "$ip" "$port" > FILE$NR
done < ip.txt

which produces output filenames like FILE1, FILE2, ... FILE1234, etc., or if you would prefer output filenames like FILE0001, FILE0002, ... FILE1234, etc. you could try:

Code:

NR=0
while IFS=/ read -r ip port
do	NR=$((NR + 1))
	FILENAME=$(printf 'FILE%04d' $NR)
	printf 'internal=yes\ninternalip= %s\ninternal.dest: %s port=%s\n' \
	    "$ip" "$ip" "$port" > "$FILENAME"
done < ip.txt

Either of these should work with any shell that attempts to follow the POSIX standard's shell syntax (such as bash, ksh, and several others; but not csh and its derivatives).