41⟩ Which of the following file set in the current directory are identified by the regular expression a?b*? a) afcc, aabb b) aabb, axbc c) abbb, abxy d) abcd, axbb
b) aabb, axbc
Linux Shell
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53 Linux Shell Questions And Answers
42⟩ When the return value of any function is not specified within the function, what function returns? a) nothing b) exit status of the last command executed c) 0 d) none of the mentioned
b) exit status of the last command executed
43⟩ * Specifies a) one or more character b) zero or more charecter c) nothing d) None of the above
b) zero or more charecter
44⟩ Which of the following command provides the list of the functions defined in the login session? a) declare -f b) declare -F c) both (a) and (b) d) none of the mentioned
c) both (a) and (b)
Explanation:
'declare -F' provides just the name of the functions and 'declare -f' provides their definitions also.
45⟩ Functions improves the shell's program-ability significantly, because a) when we invoke a function, it is already in the shell's memory, therefore a function runs faster than seperate scripts b) function provides a piece of code for repetative tasks c) both (a) and (b) d) none of the mentioned
c) both (a) and (b)
46⟩ Parameters can be passed to a function a) by using the parameter variables $1, $2, $3……. b) by using the environment variables c) both (a) and (b) d) none of the mentioned
a) by using the parameter variables $1, $2, $3…….
47⟩ What is the output of this program? #!/bin/sh san_function() { echo "Welcome to the google" printf "World of Linuxn" } unset -f san_function san_function exit 0 a) Welcome to the google b) World of Linux c) both (a) and (b) d) nothing will print
d) nothing will print
Explanation:
Function definition was deleted before calling the function. command 'unset -f function_name' deletes the function definition.
Output:
root@ubuntu:/home/google# ./test.sh
./test.sh: 6: san_function: not found
root@ubuntu:/home/google#
48⟩ What is the output of this program? #!/bin/sh echo "Just call the function" san_function san_function() { echo "This is a function" } exit 0 a) only first string will print without any error b) only second string will print without any error c) both strings will print d) none of the mentioned
d) none of the mentioned
Explanation:
Function must be defined prior to call. Hence only first string will print and program will generate an error also.
Output:
root@ubuntu:/home/globalguideline# ./test.sh
Just call the function
./test.sh: 3: san_function: not found
root@ubuntu:/home/globalguideline#
49⟩ Which command reads user input from the terminal and assign this value to a variable name? a) read b) get c) declare d) set
a) read
50⟩ Which one of the following is not a valid shell variable? a) _san b) san_2 c) _san_2 d) 2_san
d) 2_san
Explanation:
The shell variable can contain only letters(a to z or A to Z), numbers(0 to 9), or a underscore character(_) and a variable can not start with a number.
51⟩ In the shell, by default, all variables are considered and stored as a) string b) integer c) character f) float
a) string
52⟩ What is the output of this program? #!/bin/bash san_var=hello readonly san_var san_var=hi echo $san_var exit 0 a) hello b) hi c) nothing will print d) none of the mentioned
a) hello
Explanation:
After the execution of the 'readonly' command, shell will not provide the permission to overwrite the value stored in variable 'san_var'.
Output:
root@ubuntu:/home/google# ./test.sh
./test.sh: line 4: san_var: readonly variable
hello
root@ubuntu:/home/google#
53⟩ What is the output of this program? #!/bin/bash san_var=10 echo "the value of "san_var" is $san_var" exit 0 a) the value of "san_var" is 10 b) the value of is 10 c) the value of san_var is $san_var d) the value of "san_var" is $san_var
a) the value of "san_var" is 10
Output:
root@ubuntu:/home/google# ./test.sh
the value of "san_var" is 10
root@ubuntu:/home/google#
