21⟩ Which command can be used to test various file attributes a) if b) file c) test d) type
c) test
Linux Shell
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“Linux OS Shell frequently Asked Questions by expert members with experience in Linux Shell. These questions and answers will help you strengthen your technical skills, prepare for the new job test and quickly revise the concepts”
53 Linux Shell Questions And Answers
22⟩ What is the output of the following command for bash shell echo linux $0 a) linux echo b) linux linux c) linux bash d) linux
c) linux bash
23⟩ ? Specifies a) one or more character b) zero or more charecter c) one character d) None of the above
c) one character
24⟩ Which variable will display the list of the positional parameters? a) $# b) $* c) $? d) $$
b) $*
25⟩ The keyword 'local' is used a) to define a variable within a function for its local scope b) to redefine any global variable c) this is not a valid keyword d) none of the mentioned
a) to define a variable within a function for its local scope
26⟩ What command would send the output of cmd1 to the input of cmd2? a) cmd1 | cmd2 b) cmd1 || cmd2 c) cmd1 && cmd2 d) cmd1 ; cmd2 e) cmd1 cmd2
a) cmd1 | cmd2
27⟩ What is the output of this program? #!/bin/sh var="google" san_function() { var="Linux" echo $var } san_function exit 0 a) google b) Linux c) command not found d) none of the mentioned
b) Linux
Explanation:
If local variable name is same as the global variable, it overlays the variable, but only within the function.
Output:
root@ubuntu:/home/google# ./test.sh
Linux
root@ubuntu:/home/google#
28⟩ What is the output of this program? #!/bin/bash function san_function1 { echo "This is first function" } san_function2() { echo "This is second function" } san_function1 san_function2 exit 0 a) This is the first function b) This is the second function c) This is the first function This is the second function d) program will generate error because first function definition is not correct
c) This is the first function
This is the second function
29⟩ What is the output of this program? #!/bin/sh san_function1() { a=5 echo "This is the first function" san_function2 } san_function2() { echo "This is the second function" san_function3 } san_function3() { echo "This is the third function" } san_function1 exit 0 a) This is the first function This is the second function This is the third function b) This is the first function This is the third function This is the second function c) This is the second function This is the first function This is the third function d) This is the third function This is the first function This is the second function
a) This is the first function
This is the second function
This is the third function
Output:
root@ubuntu:/home/google# ./test.sh
This is the first function
This is the second function
This is the third function
root@ubuntu:/home/google#
30⟩ Which one of the following statement is true about variables in shell? a) variables do not require declaration before assigning value to them b) variables are case sensitive c) to extract the contents of a variable, we have to provide the variable a preceding $ d) all of the mentioned
d) all of the mentioned
31⟩ What is the output of this program? #!/bin/bash san_var="google" echo "$san_var" echo '$san_var' echo '"$san_var"' echo "'$san_var'" echo $san_var exit 0 a) google $san_var "$san_var" 'google' $san_var b) google google "google" 'google' google c) program will generate an error message d) program will print nothing
a) google
$san_var
"$san_var"
'google'
$san_var
Explanation:
Using double quotes does not affect the substitution of the variable, while single quotes and backslash do.
Output:
root@ubuntu:/home/google# ./test.sh
$san_var
"$san_var"
'google'
$san_var
root@ubuntu:/home/google#
32⟩ What is the output of this program? #!/bin/bash var1=10 $var1=20 echo $var1 exit 0 a) program will print 10 b) program will generate a warning message c) program will print 20 d) both (a) and (b)
d) both (a) and (b)
Explanation:
The doller sign ($) is used to access a variable's value, not to define it.
Output:
root@ubuntu:/home/google# ./test.sh
./test.sh: line 3: 10=20: command not found
10
root@ubuntu:/home/google#
33⟩ What is the output of this program? #!/bin/bash var[1]=san_1 var[2]=san_2 var[3]=san_3 echo ${var[*]} exit 0 a) san_1 b) san_2 c) san_3 d) san_1 san_2 san_3
d) san_1 san_2 san_3
Explanation:
All items of an array can be accessed by using ${[*]} or ${[@]}.
Output:
root@ubuntu:/home/google# ./test.sh
san_1 san_2 san_3
root@ubuntu:/home/google#
34⟩ To redefine a variable, it can be removed from the list of variables by using the command a) unset b) delete c) remove d) clear
a) unset
35⟩ How to feed standard output of one command to standard input of another in a single shell session? a) IO redirection can be used b) Named pipes can be used c) The pipe operator provided by the shell can be used d) It can not be done
c) The pipe operator provided by the shell can be used
36⟩ cmd > abc 2>&1 will a) Write file2 to file1 b) Write standard output and standard error to abc c) Write standard error to abc d) Write standard output to abc & standard error to monitor
b) Write standard output and standard error to abc
37⟩ The following commands gives the output like this #cat file1 file2 #cat file1 No such file or directory hello If we execute the command "cat file1 file2 1>2 2>&1" the output would be a) cat file1 No such file or directory hello b) No output is displayed c) Cat 1>2 No such file or directory d) hello
b) No output is displayed
38⟩ cat < file1 >> file2 | file3 a) file1 content will be appended to file2 and finally stored in file3 b) file1 content will be appended to file2 and file3 will be ignored c) file2 and file3 will have same content d) syntax error
d) syntax error
39⟩ Which variable is used to display number of arguments specified in command line a) $0 b) $# c) $* d) $?
b) $#
40⟩ Syntax to suppress the display of command error to monitor? a) command > &2 b) command 2> &1 c) command 2> &2 d) command 2> /dev/null
d) command 2> /dev/null
