UNIX for Dummies Questions & Answers

1) The lpr and sort utilities accept input either from a file named on the command line or from standard input.
a)Name two other utilities that function in a similar manner.

b)Name a utility that accepts its input only from standard input.




2) Explain the following error message. What filenames would a subsequent ls display?

$ ls

abc abd abe abf abg abh

$ rm abc ab*

rm: cannot remove 'abc': No such file or directory




3) How to output only the names of the files in the working directory that contain the pattern $(

This smells like homework.. snif..snif...

awk sed.

more

The glob is expanding after the file is removed which is why you get the error that the file doesn't exist.. The next ls would show . .. all the others would be rm'd

ls|grep '&('

Correct me if I am wrong someone.

No, it expand before the file is removed

Code:

rm abc ab*

expand to

Code:

rm abc abc  abd  abe  abf  abg  abh

so the abc file appears twice
when trying to remove the second one, the file is not found because it has already been removed.

Where can I read about * expansion behavior in BASH?

The "more" command can take input from either a pipe or from the command line.
The "tr" command is one command which only takes input from standard input.

The glob is expanded before the rm is executed. Therefore the "rm" attempts to remove the file "abc" twice.

Maybe try:

Code:

ls *\$\(*

Methyl, is a pipe not considered standard input?