If 7 terminals are currently logged on. then the command
date ; who | wc -l, displays
A. | date followed by 7 |
B. | date followed by 8 |
C. | date followed by 1 |
D. | an error message |
Option: A Explanation : Click on Discuss to view users comments. divya said: (4:39pm on Wednesday 15th January 2014)
Correct option is B, when i opened 2 terminals i got ans:date followed by 3
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Choose the correct answers if the command ls -l /dev/mt0 display's
brw_rw_ _ _ _ 1 root 3, 0 Apr18 1:05 mt0
A. | The 'b' indicates that it is a special file |
B. | mt0 indicates that it is a tape drive |
C. | The ' b' indicates that data transfer is done in blocks |
D. | All of these |
Option: D Explanation : For regular (ordinary) files the first character (i.e. b here), will be just a underscore. For directories d. for character special files ' ' and ' b' for a block read special file. The last column will have lp for line printer. hp for disk drives. tty for terminals etc. The 3 in 3 , denotes the major device number and - minor device number. That is. this system denotes tape drives by 3 and 0 to single out a particular tape drive from the many tape drives, the system may have. Click on Discuss to view users comments. |
Choose the correct statements.
A. | id x .o is a valid command (assume x . o exists) |
B. | cc x. s is a valid command (assume x . s exists) |
C. | Both (a) and (b) |
D. | None of these |
Option: C Explanation : Click on Discuss to view users comments. |
cat/dev/tty
A. | Throws garbage onto the terminal 1. |
B. | Just echoes what you type. line by line |
C. | Terminates if one types control at the beginning of a line |
D. | Both (b) & (c) |
Option: D Explanation : First, the i-node number corresponding to idevi tty (i.e. the terminal currently used) is procured. Then the i-node is accessed. From it, the system understands, it is a character special file. So, whatever you type, if followed by ' n ' will he echoed in the terminal. Typing control d, also lushes the buffer contents to t ty. But unlike 'control d is not transmitted. So. if you type ab ( Ad) cd ( Ad) first ab will be immediately transmitted, then cd will be transmitted. Whenever you press control d. then what you have typed between the previous control d (or from the start of the current line) to the current control d will be transmitted. So. if you type two control d consecutively or a single control d. at the beginning of a line then you are telling it to transmit. but nothing is there to be transmitted. So. the command gets terminated. Click on Discuss to view users comments. |