Answers to Review Questions
1. D. Any of these approaches will work, or at least might work. (You might err when performing any of them.) Option B or C is likely to be the most efficient approach; with a long filename to type, option A is likely to be tedious.
2. E. The echo command is implemented internally to bash, although an external version is also available on most systems. The cat, less, tee, and sed commands are not implemented internally to bash, although they can be called from bash as external commands.
3. E. The echo command echoes what follows to standard output, and $PROC is an environment variable. Thus, echo $PROC displays the value of the $PROC environment variable, meaning ...