RHCSA RHCSA Essential Command-Line Tools 2

Question 1

Which command displays the last 20 lines of a file named 'syslog'?

Accepted Answer

tail -20 syslog

Answer

head -20 syslog

Answer

cat -20 syslog

Answer

less -20 syslog

Question 2

What does the command 'wc -l filename' report?

Accepted Answer

Number of lines in the file

Answer

Number of words in the file

Answer

Number of characters in the file

Answer

File size in bytes

Question 3

Which command would you use to search for the string 'error' recursively in all files under /var/log?

Accepted Answer

grep -r 'error' /var/log

Answer

find /var/log -name 'error'

Answer

locate error /var/log

Answer

search -r 'error' /var/log

Question 4

What is the effect of running 'sort -u file.txt'?

Accepted Answer

Sorts the file and removes duplicate lines

Answer

Sorts the file in reverse order

Answer

Sorts the file and counts unique lines

Answer

Updates the file with sorted output in place

Question 5

Which sed command replaces only the FIRST occurrence of 'foo' with 'bar' on each line of input?

Accepted Answer

sed 's/foo/bar/' file

Answer

sed 's/foo/bar/g' file

Answer

sed 's/foo/bar/1g' file

Answer

sed 'g/foo/bar/' file

Question 6

What does the 'cut -d: -f1' command do when applied to /etc/passwd?

Accepted Answer

Extracts the first field using colon as delimiter

Answer

Cuts the first character of each line

Answer

Removes the first colon from each line

Answer

Extracts the first line of the file

Question 7

Which command can be used to view a file page by page, allowing both forward and backward navigation?

Accepted Answer

less

Answer

more

Answer

cat

Answer

head