010-160 Linux Command Line & Shell Scripting 5

Question 1

Which command substitution syntax stores the output of date into a variable TODAY?

Accepted Answer

TODAY=$(date)

Answer

$() performs command substitution, executing date and assigning its output to TODAY.

Question 2

What is the purpose of the shebang line #!/bin/bash at the top of a script?

Accepted Answer

It specifies the interpreter that should execute the script

Answer

The shebang tells the OS which interpreter to use when the script is executed directly.

Question 3

Which command displays the first 5 lines of a file named data.csv?

Accepted Answer

head -5 data.csv

Answer

head -n N (or the shorthand head -N) prints the first N lines of a file.

Question 4

In bash, what does the double bracket [[ ... ]] provide compared to single bracket [ ... ]?

Accepted Answer

Double brackets support pattern matching and avoid word-splitting issues

Answer

[[ ]] is a bash keyword offering regex matching, no word-splitting, and safer quoting than POSIX [ ].

Question 5

Which command would you use to find all files modified in the last 24 hours under /home?

Accepted Answer

find /home -mtime -1

Answer

find with -mtime -1 matches files whose modification time is less than 1 day (24 hours) ago.

(010-160) LPI Linux Essentials Practice Test