Linux Questions & Answers on sed Editor for Freshers

1. What is sed?

a) a non-interactive stream editor
b) an IDE
c) a hex editor
d) none of the mentioned

Answer: a

2. Sed maintains the hold space (a buffer) to

a) copy the each line of input
b) save the data for later retrieval
c) copy the each line of input & save the data for later retrieval
d) none of the mentioned

Answer: b

Explanation: To copy the each line of input, sed maintains the pattern space.

3. Which is the correct syntax for sed on command line?

a) sed [options] ‘[command]’ [filename].
b) sed ‘[command]’ [options] [filename].
c) sed [filename] [options] ‘[command]’
d) sed ‘[command]’ [filename] [options].

Answer: a

4. If any sed command does not specify any address then the command is applied to

a) each input line
b) none of the input line
c) last input line
d) none of the mentioned

Answer: a

5. If no file is specified in sed command then

a) sed command will not work
b) sed reads from standard input
c) sed reads the data already present in buffer
d) it is necessary to provide the filename

Answer: b

6. Which sed command deletes the specified address range

a) [address range]/s
b) [address range]/p
c) [address range]/d
d) [address range]/y

Answer: c

Explanation: To use the command correct syntax specified for sed editor should be followed.

7. Which command is used to replace word ‘cat’ (already present in the file) with ‘mouse’ at all places in a file ‘old.txt’ and save the result in a new file ‘new.txt’?

a) sed ‘s/cat/mouce/g’ old.txt > new.txt
b) sed ‘s/cat/mouse’ old.txt new.txt
c) sed ‘/s/cat/mouse/g’ old.txt new.txt
d) sed ‘/s/cat/mouse’ old.txt > new.txt

Answer: a

8. Which command will delete all the blank lines in file old.txt?

a) sed ‘/d’ old.txt
b) sed ‘/^/d’ old.txt
c) sed ‘/^$/d’ old.txt
d) sed ‘/^*/d’ old.txt

Answer: c

9. The command “sed -n ‘/sanfoundry/p’ old.txt” will

a) print the lines containing the word ‘sanfoundry’ in file old.txt
b) delete the lines containing the word ‘sanfoundry’ in file old.txt
c) will generate an error message
d) none of the mentioned

Answer: a

10. Which option is used by sed to specify that the following string is an instruction or set of instructions?

a) -n
b) -e
c) -f
d) -i

Answer: a