grep da * 2

# check command line arguments
if [ $# -eq 0 ]
then
echo "wrong number of command line arguments"
echo "Usage: `basename $0` -?"
echo "
or"
echo "
`basename $0` -d <file_to_be_deleted>"
echo "
or"
echo "
`basename $0` -f <text> <number_of_lines> <outfile>"
exit
fi
if [ $# -eq 1 ]
then
if [ "$1" != "-?" ]
then
echo "incorrect command line argument: $1"
fi
echo "Usage: `basename $0` -?"
echo "
or"
echo "
`basename $0` -d <file_to_be_deleted>"
echo "
or"
echo "
`basename $0` -f <text> <number_of_lines> <outfile>"
exit
fi
if [ $# -eq 2 ]
then
if [ "$1" == "-d" ]
then
echo "removing file $2"
rm $2
exit
else
echo "incorrect command line argument: $1"
echo "Usage: `basename $0` -?"
echo "
or"
echo "
`basename $0` -d <file_to_be_deleted>"
echo "
or"
echo "
`basename $0` -f <text> <number_of_lines> <outfile>"
exit
fi
fi
if [ $# -eq 3 ]
then
echo "wrong number of command line arguments"
echo "Usage: `basename $0` -?"
echo
echo
echo
echo
exit
if [ $# -eq 4 ]
then
if [ "$1" != "-f" ]
then
echo "incorrect command line argument: $1"
echo "Usage: `basename $0` -?"
echo "
or"
echo "
`basename $0` -d <file_to_be_deleted>"
echo "
or"
echo "
`basename $0` -f <text> <number_of_lines> <outfile>"
exit
fi
fi
if [ $# -gt 4 ]
then
echo "wrong number of command line arguments"
echo "Usage: `basename $0` -?"
echo "
or"
echo "
`basename $0` -d <file_to_be_deleted>"
echo "
or"
echo "
`basename $0` -f <text> <number_of_lines> <outfile>"
exit
fi
# so the command line arguments are OK
# redirect standard output to $4
>$4
# loop through and create the lines and ad them to $4
for ((i=1; i<=$3; i++))
do
echo "$2**$i">>$4
done
# show the created file
cat $4