CSE105

Which of the following commands is implemented as an internal command in bash?

• cat

• echo

• tee

• sed

What does the pwd command accomplish?

• It prints the name of the working directory.

• It changes the current working directory.

• It prints wide displays on narrow paper.

• It parses Web page URLs for display.

What is the surest way to run a program (say, myprog) that’s located in the current working

directory?

• Type ./ followed by the program name: ./myprog.

• Type the program name alone: myprog.

• Type run followed by the program name: run myprog.

• Type /. followed by the program name: /.myprog.

You want to store the standard output of the ifconfig command in a text file (file.txt) for

future reference, and you want to wipe out any existing data in the file. How can you do so?

• ifconfig < file.txt

• ifconfig >> file.txt

• ifconfig > file.txt

• ifconfig | file.txt

What is the effect of the following command?

$ ./myprog &> input.txt

• Standard error to myprog is taken from input.txt.

• Standard input to myprog is taken from input.txt.

• Standard output and standard error from myprog are written to input.txt.

• All of the above.

How many commands can you pipe together at once?

• 2

• 3

• 4

• An arbitrary number

A text-mode program, verbose, prints a lot of spurious “error” messages to standard error.

How might you get rid of those messages while still interacting with the program?

• verbose | quiet

• verbose &> /dev/null

• verbose 2> /dev/null

• verbose > junk.txt

You want to run an interactive script, gabby, which produces a lot of output in response to the user’s inputs. To facilitate future study of this script, you want display it's output to your screen and copy its output to a file simultaneously. How might you do this?

• gabby > gabby-out.txt

• gabby | tee gabby-out.txt

• gabby < gabby-out.txt

• gabby &> gabby-out.txt

How do the > and >> redirection operators differ?

• The > operator creates a new file or overwrites an existing one; the >> operator creates

  a new file or appends to an existing one.

• The > operator creates a new file or overwrites an existing one; the >> operator

  appends to an existing file or issues an error message if the specified file doesn’t exist.

• The > operator redirects standard output; the >> operator redirects standard error.

• The > operator redirects standard output; the >> operator redirects standard input.

What program would you use to display the end of a configuration file?

• uniq

• cut

• tail

• wc