The following command shows the use of this operator that will multiply 5 by 7 and print 25 as output. The following script shows the use of this operator. ‘&&’ is a comparison operator that is used for creating Boolean AND logic. AND & OR Operator (&& and ||) Combination of && Operator & OR Operator (||) is quite interesting … # Caution advised, however. is boolean operator, which is used to test whether expression is true or not. The following script shows the use of this operator. ‘+=’ is a shorthand arithmetic operator that adds an integer value with the value of a variable and store the result in that variable. Be extra careful when using this operator as you may overwrite an important file. ‘-=’ is a shorthand arithmetic operator that subtract numeric value from a variable and store the result in that variable. We have all ready provided tutorial and examples about grep and egrep. Bash AND logical operator can be used to form compound boolean expressions for conditional statements or looping statements. The script is executed two times with valid data and invalid data in the following output. The most used 74 bash operators are explained in this article with examples. To check if two strings are not equal in bash scripting, use bash if statement and not equal to!= operator. blank. 2. The following script shows the use of this operator. ‘-G’ operator is used to check both group id of the file and the login user is the same. The value of $i will be decremented before adding with the number 15 in the following example. ‘-ne’ operator is used to check two numbers are not equal or equal. The > redirection operator writes the output to a given file. ‘==’ operator is used to compare the equality of two values. Basically, these operators are used in simple mathematical calculations like addition and multiplications. Boolean logic operators mainly used with conditional statements where we can get more information from the following tutorial. ‘!’ operator is used to create logical NOT condition that changes true to false or false to true. The following script shows the use of this operator. Using Regex Operator # Another option to determine whether a specified substring occurs within a string is to use the regex operator =~. ‘-u’ operator is used to check the user id (SUID) is set or not for a file. ", "$1 and $2 are hard links of the same file. ‘-ge’ operator is used to compare two numbers and it returns true if any number is greater than or equal to the other number. ‘-s’ operator is used to check the file size is more than zero or not. ‘-a’ operator is used to create Boolean AND logic within two or more conditions. The following script shows the use of this operator. Different types of operators exist in Bash to perform various operations using bash script. ‘-h’ operator is used to check the file is a symbolic link or not. You should read the bash man pages, under the [[ expression ]] section. ‘-d’ operator is used to check any folder exists or not. ‘<‘ operator is used to compare two string values and it returns true if the first value is less than second value. In this tutorial we will look grep command or, and, not logic operations in detail. Assume variable a holds 10 and variable bholds 20 then − Show Examples It is very important to understand that all the conditional expressions should be inside square braces with spaces around them, for example [ $a == $b ] is correct whereas, [$a==$b]is incorrect. In this example, the current value of $i will be printed first and incremented by 1 in the second command that is 10. Linux Grep OR, AND, NOT Operator and Logic Examples. I am a trainer of web programming courses. Addition (+):Simply adds values of the two given variables. The following script shows the use of this operator. Some common groups of bash operators are arithmetic operators, comparison operators, bit-wise operators, logical operators, string operators, and file operators. The following script shows the use of this operator. The following script shows the use of this operator. The right side of && will only be evaluated if the exit status of the left side is zero (i.e. In the following example, the value of $n will be added with 30 and store the result in $n. ‘^’ operator is used to perform bitwise XOR operation that works on binary data. The following script shows the use of this operator. ‘%=’ is a shorthand arithmetic operator that calculates the remainder after dividing the values of a variable by a number and store the remainder value into that variable. ", "File does not have execution permission. 15/10/2017 by İsmail Baydan. ‘-O’ operator is used to check the ownership of the file. Similar to &&-o. Logical not (!) AND operator returns true if both the operands are true, else it returns false. Each operator returns true (0) if the condition is met and false (1) if the condition is not met. The script is executed without argument and with the argument in the following example. 3. ‘>>’ operator is used to right-shift the binary value. The following script shows the use of this operator. 1210 Kelly Park Cir, Morgan Hill, CA 95037. ‘-o’ operator is used to create Boolean OR logic within two or more conditions. ‘-eq’ operator is used to check two values are equal or not. Examples/Variations column contains some of the variations of arithmetic expansion. The following arithmetic operators are supported by Bourne Shell. The test and [commands determine their behavior based on the number of arguments; see the descriptions of those commands for any other command-specific actions.. ‘>>=’ operator is used to right-shift the binary value of any variable and store the value in that variable. The following script shows the use of this operator. If ‘–‘ operator is used after the variable, then it will act as a post-decrement operator and it decrements the value of the variable by 1 after doing another task. Example – 2: Using ‘let’ command ‘let’ is another built-in command to do arithmetic operations in bash.‘let’ command can’t print the output to the terminal without storing the value in a variable. If command1 fails for any reason, command2 won't run. Otherwise, the file is created. The -z and -n operators are used to verify whether the string is Null or not. -e test operator is used to check any file or folder is exists or not. The last command will print the value of $i , which is 11. Ex. If the test inside evaluates to true, it returns zero; it returns nonzero otherwise. ‘<=’ operator is used to compare two numbers and it returns true if any number is less than or equal to the other number. The following command shows the use of this operator. ‘**’ operator is used to calculate the xy.