Sams Teach Yourself Shell Programming in 24 Hours, Second Edition

Hour 9

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.
A1:	The following command will accomplish this task: $ ls *hw[0-9][0-9][2-6].???
2:	What action is performed by the following line, if the variable MYPATH is unset: : ${MYPATH:=/usr/bin:/usr/sbin:/usr/ucb}
A2:	If MYPATH is unset, it is set to the given value, which is then substituted.
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}
A3:	If MYPATH is unset, the given value is substituted ...