Ubuntu Unleashed 2019 Edition: Covering 18.04, 18.10, 19.04

if  [   $number1    -gt $number2    ];  then

            echo    "number1    is  greater than    number2"

else

            echo    "number1    is  not greater than    number2"

fi

if  [   $number1    -ge $number3    ];  then

            echo    "number1    is  greater than    or  equal   to  number3"

else

            echo    "number1    is  not greater than    or  equal   to  number3"

fi

if  [   $number1    -lt $number2    ];  then

            echo    "number1    is  less    than    number2"

else

            echo    "number1    is  not less    than    number2"

fi

if  [   $number1    -le $number3    ];  then

            echo    "number1    is  less    than    or  equal   to  number3"

else

            echo    ""number1   is  not less    than    or  equal   to  number3"

fi

When you execute the shell program, you get the following results:

Click here to view code image
number1 is equal to number3
number1 is not equal to number2
number1 is not greater than number2
number1 is greater than or equal to number3
number1 is less than number2
number1 is less than or equal to number3

File Operators

You can use the following operators as file comparison operators:

-d—Determines   whether a   file    is  a   directory

-f—Determines   whether a   file    is  a   regular file

-r—Determines   whether read    permission  is  set for a   file

-s—Determines   whether a   file    exists  and has a   length  greater than    zero

-w—Determines   whether write   permission  is  set for a   file

-x—Determines   whether execute permission  is  set for a   file

Assume that a shell program called compare3 is in a directory with a file