SHELL

bash scripts arguments

# bash arguments cheatsheet
$1, $2, ... -> are the positional parameters.
"$@"        -> is an array-like construct of all positional parameters, {$1, $2, $3 ...}.
"$*"        -> is the IFS expansion of all positional parameters, $1 $2 $3 ....
$#          -> is the number of positional parameters.
$-          -> current options set for the shell.
$$          -> pid of the current shell (not subshell).
$_          -> most recent parameter (or the abs path of the command to start the current shell immediately after startup).
$IFS        -> is the (input) field separator.
$?          -> is the most recent foreground pipeline exit status.
$!          -> is the PID of the most recent background command.
$0          -> is the name of the shell or shell script.

How to Pass Arguments to a Bash Script

makereport -u jsmith -p notebooks -d 10-20-2011 -f pdf

#!/bin/bash
while getopts u:d:p:f: option
do
case "${option}"
in
u) USER=${OPTARG};;
d) DATE=${OPTARG};;
p) PRODUCT=${OPTARG};;
f) FORMAT=${OPTARG};;
esac
done