Arguments
Command arguments
#!/bin/bash

# bash a.sh p1 p2

# print the first argument
echo $1 # p1

# print all arguments
echo $@ # p1 p2
echo $* # p1 p2

# print number of arguments
echo $# # 2
getopts
#!/bin/bash

#bash a.sh -u lchen -f dat

while getopts u:f: option
do
	case "$option" in
	u) U=${OPTARG};;
	f) F=${OPTARG};;
	esac
done

echo $U # lchen
echo $F # txt
Reference