UNIX was originally developed at:
A) MIT
B) AT&T Bell Labs
C) Microsoft
D) IBM
Answer: B

UNIX is a:
A) Single-user operating system
B) Multi-user operating system
C) Real-time system
D) None
Answer: B

UNIX is written mostly in:
A) C
B) Assembly
C) Pascal
D) Java
Answer: A

The UNIX kernel is:
A) Hardware
B) Software
C) Both
D) None
Answer: B

The kernel interacts with:
A) Hardware and shell
B) User directly
C) Application software only
D) None
Answer: A

The shell in UNIX is:
A) Command interpreter
B) Kernel
C) File manager
D) Hardware driver
Answer: A

The core of UNIX operating system is:
A) Kernel
B) Shell
C) Commands
D) Utilities
Answer: A

Which of the following is not a UNIX shell?
A) Bourne shell
B) Korn shell
C) PowerShell
D) C shell
Answer: C

Command prompt for Bourne shell is:
A) $
B) #
C) %
D) >
Answer: A

UNIX file system is organized as a:
A) Hierarchical tree
B) Linear list
C) Network model
D) Flat model
Answer: A

Command to list files in a directory:
A) ls
B) list
C) show
D) dir
Answer: A

To change directory:
A) cd
B) chdir
C) cdir
D) path
Answer: A

To print working directory:
A) pwd
B) path
C) showdir
D) list
Answer: A

To create a new directory:
A) mkdir
B) makedir
C) newdir
D) createdir
Answer: A

To remove a directory:
A) rmdir
B) deldir
C) removedir
D) dirrm
Answer: A

Command to copy files:
A) cp
B) copy
C) cpy
D) dup
Answer: A

Command to move or rename files:
A) mv
B) move
C) ren
D) shift
Answer: A

Command to remove a file:
A) rm
B) del
C) erase
D) delete
Answer: A

To view contents of a file:
A) cat
B) view
C) open
D) print
Answer: A

To display file page by page:
A) more
B) cat
C) show
D) ls
Answer: A

To change file permissions:
A) chmod
B) chown
C) perm
D) modfile
Answer: A

To change file owner:
A) chown
B) chgrp
C) own
D) setowner
Answer: A

To change group ownership:
A) chgrp
B) chown
C) grpown
D) groupmod
Answer: A

Default file permissions are controlled by:
A) umask
B) chmod
C) chown
D) maskset
Answer: A

Permission value 777 means:
A) Full permission for all
B) No permission
C) Read-only
D) Execute-only
Answer: A

Permission value 644 means:
A) Owner read/write, group/others read
B) Owner full
C) Group full
D) All read/write
Answer: A

Execute permission on a directory allows:
A) Entering the directory
B) Deleting files
C) Listing contents
D) Editing files
Answer: A

Read permission on a directory allows:
A) Listing directory contents
B) Executing files
C) Creating new files
D) None
Answer: A

To view file permissions:
A) ls -l
B) cat -p
C) chmod -v
D) showperm
Answer: A

Superuser in UNIX is:
A) root
B) admin
C) user1
D) sys
Answer: A

Command to concatenate and display files:
A) cat
B) join
C) paste
D) show
Answer: A

To display first 10 lines of a file:
A) head
B) tail
C) start
D) less
Answer: A

To display last 10 lines of a file:
A) tail
B) head
C) last
D) showend
Answer: A

To count number of lines, words, and characters:
A) wc
B) count
C) lines
D) stats
Answer: A

To sort contents of a file:
A) sort
B) order
C) seq
D) arrange
Answer: A

To find difference between two files:
A) diff
B) cmp
C) compare
D) check
Answer: A

To compare binary files:
A) cmp
B) diff
C) compare
D) bdiff
Answer: A

To merge file contents line by line:
A) paste
B) join
C) cat
D) merge
Answer: A

To display unique lines:
A) uniq
B) sort -u
C) Both A and B
D) distinct
Answer: C

To find lines matching a pattern:
A) grep
B) find
C) search
D) awk
Answer: A

To list running processes:
A) ps
B) jobs
C) top
D) All of the above
Answer: D

To terminate a process:
A) kill PID
B) end PID
C) stop PID
D) exit PID
Answer: A

To suspend a job:
A) Ctrl+Z
B) Ctrl+C
C) Ctrl+D
D) Ctrl+X
Answer: A

To resume a stopped job:
A) fg
B) bg
C) resume
D) restart
Answer: A

To run a process in background:
A) command &
B) bg command
C) run command
D) background command
Answer: A

To view background jobs:
A) jobs
B) ps -b
C) viewjobs
D) listjobs
Answer: A

To schedule a command to run later:
A) at
B) cron
C) schedule
D) timer
Answer: A

To schedule recurring jobs:
A) cron
B) at
C) repeat
D) schedule
Answer: A

To view active cron jobs:
A) crontab -l
B) cron -v
C) showcron
D) listcron
Answer: A

To remove all cron jobs:
A) crontab -r
B) remove cron
C) clearcron
D) delcron
Answer: A

51. Default shell in most UNIX systems is:
    A) Bourne Shell (sh)
    B) Korn Shell (ksh)
    C) C Shell (csh)
    D) Bash
    Answer: A

52. Command to check the shell used by a user:
    A) echo $SHELL
    B) shellname
    C) show shell
    D) whoami shell
    Answer: A

53. Command to see all environment variables:
    A) env
    B) printenv
    C) set
    D) All of the above
    Answer: D

54. To set an environment variable:
    A) export VAR=value
    B) set VAR=value
    C) put VAR=value
    D) declare VAR=value
    Answer: A

55. To remove an environment variable:
    A) unset VAR
    B) export -d VAR
    C) remove VAR
    D) delete VAR
    Answer: A

56. To check your login name:
    A) whoami
    B) logname
    C) user
    D) uname -u
    Answer: A

57. To display all logged-in users:
    A) who
    B) users
    C) w
    D) All of the above
    Answer: D

58. To display system name and version:
    A) uname -a
    B) sysver
    C) version
    D) showver
    Answer: A

59. To print current date and time:
    A) date
    B) time
    C) showdate
    D) now
    Answer: A

60. Command to display calendar:
    A) cal
    B) calendar
    C) showcal
    D) date -c
    Answer: A

61. Symbol > is used for:
    A) Output redirection
    B) Input redirection
    C) Piping
    D) None
    Answer: A

61. Symbol < is used for:
    A) Input redirection
    B) Output redirection
    C) Background execution
    D) Piping
    Answer: A

62. Symbol >> is used to:
    A) Append output to file
    B) Overwrite file
    C) Merge files
    D) Compare files
    Answer: A

63. Symbol | is used for:
    A) Pipe output of one command to another
    B) Redirect input
    C) Comment
    D) Break line
    Answer: A

64. Command to suppress error messages:
    A) 2>/dev/null
    B) 1>/dev/null
    C) >/dev/null 2>&1
    D) Both A and C
    Answer: D

65. To read input from keyboard:
    A) read variable
    B) input variable
    C) cat > file
    D) key variable
    Answer: A

66. Standard input file descriptor:
    A) 0
    B) 1
    C) 2
    D) 3
    Answer: A

67. Standard output file descriptor:
    A) 1
    B) 0
    C) 2
    D) 3
    Answer: A

68. Standard error file descriptor:
    A) 2
    B) 0
    C) 1
    D) 3
    Answer: A

69. Command to combine stdout and stderr:
    A) command >file 2>&1
    B) command 2>file
    C) command <file
    D) command | file
    Answer: A

71. Default UNIX text editor:
    A) vi
    B) nano
    C) pico
    D) emacs
    Answer: A

72. To open a file in vi:
    A) vi filename
    B) open filename
    C) edit filename
    D) vim filename
    Answer: A

73. To enter insert mode in vi:
    A) i
    B) a
    C) o
    D) All of the above
    Answer: D

74. To save and quit vi:
    A) :wq
    B) ZZ
    C) 😡
    D) All of the above
    Answer: D

75. To quit vi without saving:
    A) :q!
    B) :q
    C) :exit
    D) :stop
    Answer: A

76. To delete a single line in vi:
    A) dd
    B) dl
    C) x
    D) D
    Answer: A

77. To delete from cursor to end of line:
    A) D
    B) x
    C) dl
    D) d$
    Answer: D

78. To search text in vi:
    A) /text
    B) ?text
    C) Both A and B
    D) find text
    Answer: C

79. To replace text in vi:
    A) :%s/old/new/g
    B) replace old new
    C) find old replace new
    D) :sub old new
    Answer: A

80. To undo last change:
    A) u
    B) U
    C) :undo
    D) All of the above
    Answer: A

81. Filter command to display lines with a pattern:
    A) grep
    B) find
    C) search
    D) awk
    Answer: A

82. Command to substitute text using stream editor:
    A) sed
    B) awk
    C) grep
    D) tr
    Answer: A

83. To print specific fields in a file:
    A) awk ‘{print $1}’
    B) cut -f1
    C) Both A and B
    D) paste
    Answer: C

84. Command to remove control characters:
    A) tr -d
    B) rm -c
    C) del -cc
    D) strip
    Answer: A

85. Command to translate lowercase to uppercase:
    A) tr a-z A-Z
    B) tr lower upper
    C) sed ‘s/a/A/’
    D) awk ‘{toupper}’
    Answer: A

86. To split a file into parts:
    A) split
    B) cut
    C) divide
    D) chunk
    Answer: A

87. To join files horizontally:
    A) paste
    B) join
    C) cat
    D) merge
    Answer: A

88. To join files by common field:
    A) join
    B) paste
    C) merge
    D) cut
    Answer: A

89. Command to sort lines:
    A) sort
    B) order
    C) seq
    D) arrange
    Answer: A

90. To display only unique lines:
    A) uniq
    B) sort -u
    C) Both A and B
    D) distinct
    Answer: C

91. Root directory symbol in UNIX:
    A) /
    B) ~
    C) \
    D) home
    Answer: A

92. Home directory symbol:
    A) ~
    B) /
    C) .
    D) ..
    Answer: A

93. Current directory symbol:
    A) .
    B) ..
    C) /
    D) ~
    Answer: A

94. Parent directory symbol:
    A) ..
    B) .
    C) /
    D) ~
    Answer: A

95. To display disk space usage:
    A) df
    B) du
    C) Both A and B
    D) ls -s
    Answer: C

96. To display file system type:
    A) df -T
    B) mount
    C) cat /proc/filesystems
    D) All of the above
    Answer: D

97. To check file system errors:
    A) fsck
    B) chkdsk
    C) diskfix
    D) verifyfs
    Answer: A

98. To mount a device:
    A) mount
    B) attach
    C) connect
    D) link
    Answer: A

99. To unmount a device:
    A) umount
    B) unmount
    C) detach
    D) remove
    Answer: A

100. To list mounted file systems:
     A) mount
     B) df
     C) cat /etc/mtab
     D) All of the above
     Answer: D