781. Which of the following is not a communication command ?
A. grep
B. mail
C. mesg
D. write

782. What command is used to remove files ?
A. dm
B. rm
C. delete
D. erase

783. Which command is used to terminate all processes in your own system except the login shell ?
A. kill 1
B. kill 0
C. cancel all
D. cancel 1

784. Which of the following shell’s wildcards are used to match any number of characters including none ?
A. [ijk]
B. [!ijk]
C. ?
D. *

785. Which of the following special shell variables is used to process number of the current shell ?
A. $!
B. $$
C. 0
D. $*

786. Which of the following command is used to go to home directory ?
A. cd..
B. cd/
C. cd
D. cd HOME.

787. In Bourne shell, which file sets the Unix environment for the user when the logs into his HOME directory ?
A. .exrc
B. .profile
C. lastlogin
D. .mbox

788. Which commands is used to assign executable permission to all of the files named “letter” ?
A. chmod ugo+r letter
B. chmod ugo+rw letter
C. chmod u+x letter
D. chmod ugo+x letter

789. Which command is used to make all files and sub-directories in the directory (progs) executable by all users ?
A. chmod -R a+x progs
B. chmod -R 222 progs
C. chmod -1 a+x progs
D. chmod -x a+x progs

790. Which command is used to concatenate all files beginning with the string ’emp’ and followed by a non-numeric characters ?
A. cat emp[!0-9]
B. more [emp][!0-9]
C. cat emp[x-z]
D. cat emp[a-z]

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