Linux-Shell Programming

December 23, 2010 3-minute read

linux

Write a program to print details of currently logged in users,
print date and calendar?

 #/bin/bash
 echo "Current login users: `who`"
 echo "Date: `date`"
 echo "Calendar: `cal`"

Write a program to define user defined variables ‘x’ with value
‘10’ and ‘y’ ‘20’ and print it on screen?
```
 #/bin/bash
 a=10
 b=20
 echo "a = $a , b = $b"
```
Write a program to print current shell, present working directory,
and username, using system variable?
```
 #/bin/bash
 echo "Shell: $SHELL"
 echo "Current Directory: `pwd`"
 echo "User name: `whoami`"
```
Write a program to print the sum of two numbers a=10, b=20?
```
 #/bin/bash
 a=10
 b=20
 echo "Sum: `expr $a + $b`"
```

Write a program to read two numbers from the keyboard and to print
the sum, product and quotient of the numbers?

 #/bin/bash
 echo "Enter the first number: "
 read a
 echo "Enter the second number: "
 read b
 sum=`expr $a + $b`
 echo "Sum is: $sum"
 pro=`expr $a \* $b`
 echo "Product is: $pro"
 quo=`expr $a / $b`
 echo "Quotient is: $quo"

Write a program to obtain and print the status of any one command?

 #/bin/bash
 echo "hi"
 a=$?
 if [ $a -eq 0 ]
 then
 echo "Execution successfully completed"
 else
 echo "Execution failed"
 fi

Write a program to check the following condition:
Read a number from the keyboard; if that number is greater than ‘0’
then print as “Positive”, else print as “Negative”?
```
 #/bin/bash
 echo "Enter a number: "
 read a
 if [ $a -gt 0 ]
 then
 echo "Number is positive"
 else
 echo "Number is negative"
 fi
```
Write a program to implement choices:
                         1. Windows
                         2. Linux
                         Select your choice [1 or 2]
Read the choice from keyboard. If that is ‘1’ the print “Windows”, if
that is ‘2’ then print “Linux” else print “You don’t like Windows or
Linux”?
```
 #/bin/bash
 echo "1. Windows"
 echo "2. Linux"
 echo "    Select [1 or 2]"
 read ch
 if [ $ch -eq 1 ]
 then
 echo "Windows"
 else if [ $ch -eq 2 ]
 then
 echo "Linux"
 else
 echo "You dont like Windows or Linux"
 fi
 fi
```

Write a program to prepare students record consisting of name,
roll no, and marks of three subjects. Take sum of the three marks and
print all details of student with total mark?

 #/bin/bash
 echo "Enter Student Details"
 echo "Name: "
 read name
 echo "Roll No: "
 read roll
 echo "Mark1: "
 read m1
 echo "Mark2: "
 read m2
 echo "Mark3: "
 read m3
 tot=`expr $m1 + $m2 + $m3`
 echo "Student Record"
 echo "Name: $name"
 echo "Roll No: $roll"
 echo "Total marks: $tot"

Write a program to print cut 5 to 8 columns from any textile?
```
#/bin/bash
cut -c 5-8 textile
```
Write a simple program using awk?
```
#/bin/bash
awk '{ print $1 }' textile
```
Write a program to search a specific word from a file, first read
word from keyboard then using grep command search that word, and take
status of that command, if status is success the print “Word Found”
else print “Word not Found”?
```
#/bin/bash
echo "Enter a pattern to search"
read pat
grep $pat textile
if [ $? -eq 0 ]
then
echo "Word Found"
else
echo "Not found"
fi
```