Correct Answer : cut
Explanation : To extract specific columns from a file, we can use cut command followed by -c option and list of column numbers, delimited by a comma. For example,
$ cut -c 6-22,24-32 emp.lst​
Correct Answer : su
Explanation : Any user can acquire the status of superuser by using the su command. The only condition that needs to be fulfilled here is, he/she must be aware of the root password. For example,
$ su Password: ***** //root’s password #pwd /home/abd //prompt changes ( super user mode)​
Correct Answer : du
Explanation : Sometimes, we may need to find out the consumption of a specific directory rather than an entire file system. For this purpose, du command is used. This command reports usage by recursive examination of the directory structure.
Correct Answer : chmod +x
Explanation : Before we run the script, it is essential to make the script executable first. After that invoke the script name to run the script. For making the script executable, we have to use chmod +x script_name.