In unix, write the smallest regular expression that matches any string that contains a

substring consisting of $2$ or more W characters followed by a substring consisting of $3$ or

more $H$ characters.

in unix, write the smallest regular expression that matches any string that matches a

three character substring where $M$ is the first character of the substring and $N$ is the last

charcter of the substring and in between can be any character other than a newline.

Write a Unix command that puts the names of the files in your directory into a file names

myfiles.

Write a unix command that reads the datastream on standard input and writes it all to

standard output, removing first instance of "DELETE ME$"$ on each line. $($think of replacing

"DELETE ME$"$ with nothing.$)$

Write a unix command that reads the datastream on standard input and writes it all to

standard output, removing every instance of "DELETE ME$"$ on each line. $($think of replacing

"DELETE ME$"$ with nothing.$)$