Sams Teach Yourself Shell Programming in 24 Hours, Second Edition

Questions

1:	What combination of wildcards should you use to list all the files in the current directory that end in the form hwXYZ.ABC? Here X and Y can be any number; Z is a number between 2 and 6; and A, B, and C are characters.
2:	What action is performed by the following line, if the variable MYPATH is unset: : ${MYPATH:=/usr/bin:/usr/sbin:/usr/ucb}
3:	What is the difference between the actions performed by the command given in the previous problem and the action performed by the following command: : ${MYPATH:-/usr/bin:/usr/sbin:/usr/ucb}
4:	What is the output of the following command (figure it out by yourself before typing it into the shell): echo $(( 3 * 2 + ( 4 – 3 / 4) ))