1.Which command is utilized to substitute a single character with different text?
2.Which command is used to remove a file from the system?
3.What does the acronym NIS stand for?
4.Which file is used to list users who are prohibited from logging into the system through FTP?
5.Which layer is the first layer in the OSI model?
6.In the vi editor, which command allows you to move the cursor to the start of the previous word?
7.Which command is utilized to display the number of lines, words, and characters in a file?
8.What is the primary purpose of the cat command in Unix/Linux?
9.Which key is used to remove the character located directly under the cursor?
10.In the UNIX file system, data is stored in physical blocks of what size?
11.Which command is utilized to delete files from the system?
12.Which command sets read-only access for the user, group, and others on the file named 'note'?
13.Which command is used to control whether a user can receive incoming messages?
14.Which command is typically used to change the name of a file in a Unix-like system?
15.In the permission string, what does the second group of three characters (r--) signify?
16.Which command displays files sorted according to their modification timestamps?
17.Which special shell variable holds the process ID of the most recent background job?
18.Which character should be placed before the pattern 'pat' in the grep command to find matches only at the start of a line?
19.Which command will revoke the read permission for the file 'note' from both the group and others?
20.Which command in the vi editor removes three consecutive words?