![\"Arithmetic](\"https:\/\/www.tecmint.com\/wp-content\/uploads\/2019\/01\/do-simple-math-in-cli-using-double-parenthesis.png\")
<\/a><\/p>\nArithmetic in Linux Bash Shell<\/p>\n<\/div>\n
2. Using expr Command<\/h3>\n
The\u00a0expr command<\/strong>\u00a0evaluates expressions and prints the value of provided expression to standard output. We will look at different ways of using\u00a0expr<\/strong>\u00a0for doing simple math, making comparison, incrementing the value of a variable and finding the length of a string.<\/p>\n The following are some examples of doing simple calculations using the\u00a0expr command<\/strong>. Note that many operators need to be escaped or quoted for shells, for instance the\u00a0 Basic Arithmetic Using expr Command in Linux<\/p>\n<\/div>\n Next, we will cover how to make comparisons. When an expression evaluates to false, expr will print a value of\u00a00<\/strong>, otherwise it prints\u00a01<\/strong>.<\/p>\n Let\u2019s look at some examples:<\/p>\n Comparing Arithmetic Expressions in Linux<\/p>\n<\/div>\n You can also use the\u00a0expr<\/strong>\u00a0command to increment the value of a variable. Take a look at the following example (in the same way, you can also decrease the value of a variable).<\/p>\n Increment Value of a Variable<\/p>\n<\/div>\n Let\u2019s also look at how to find the length of a string using:<\/p>\n Find Length of a String<\/p>\n<\/div>\n For more information especially on the meaning of the above operators, see the\u00a0expr<\/strong>\u00a0man page:<\/p>\n bc (Basic Calculator)<\/a>\u00a0is a command-line utility that provides all features you expect from a simple scientific or financial calculator. It is specifically useful for doing floating point math.<\/p>\n If\u00a0bc command<\/strong>\u00a0not installed, you can install it using:<\/p>\n Once installed, you can run it in interactive mode or non-interactively by passing arguments to it \u2013 we will look at both case. To run it interactively, type the command\u00a0bc<\/strong>\u00a0on command prompt and start doing some math, as shown.<\/p>\n Start bc in Non-Interactive Mode<\/p>\n<\/div>\n The following examples show how to use\u00a0bc<\/strong>\u00a0non-interactively on the command-line.<\/p>\n Do Math Using bc in Linux<\/p>\n<\/div>\n The\u00a0 Do Math with Floating Numbers<\/p>\n<\/div>\n Awk<\/a>\u00a0is one of the most prominent text-processing programs in GNU\/Linux. It supports the addition, subtraction, multiplication, division, and modulus arithmetic operators. It is also useful for doing floating point math.<\/p>\n You can use it to do basic math as shown.<\/p>\n Do Basic Math Using Awk Command<\/p>\n<\/div>\n If you are new to\u00a0Awk<\/strong>, we have a complete series of guides to get you started with learning it:\u00a0Learn Awk Text Processing Tool<\/a>.<\/p>\n The\u00a0factor command<\/strong>\u00a0is use to decompose an integer into prime factors. For example:<\/p>\n Factor a Number in Linux<\/p>\n<\/div>\n That\u2019s all! In this article, we have explained various useful ways of doing arithmetic\u2019s in the Linux terminal.<\/p>\n*<\/code>\u00a0operator (we will look at more under comparison of expressions).<\/p>\n$ expr 3 + 5\r\n$ expr 15 % 3\r\n$ expr 5 \\* 3\r\n$ expr 5 \u2013 3\r\n$ expr 20 \/ 4\r\n<\/pre>\n
<\/a><\/p>\n$ expr 5 = 3\r\n$ expr 5 = 5\r\n$ expr 8 != 5\r\n$ expr 8 \\> 5\r\n$ expr 8 \\< 5\r\n$ expr 8 \\<= 5\r\n<\/pre>\n
<\/a><\/p>\n$ NUM=$(( 1 + 2))\r\n$ echo $NUM\r\n$ NUM=$(expr $NUM + 2)\r\n$ echo $NUM\r\n<\/pre>\n
<\/a><\/p>\n$ expr length \"This is Tecmint.com\"\r\n<\/pre>\n
<\/a><\/p>\n$ man expr\r\n<\/pre>\n
3. Using bc Command<\/h3>\n
$ sudo apt install bc #Debian\/Ubuntu\r\n$ sudo yum install bc #RHEL\/CentOS\r\n$ sudo dnf install bc #Fedora 22+\r\n<\/pre>\n
$ bc \r\n<\/pre>\n
<\/a><\/p>\n$ echo '3+5' | bc\r\n$ echo '15 % 2' | bc\r\n$ echo '15 \/ 2' | bc\r\n$ echo '(6 * 2) - 5' | bc\r\n<\/pre>\n
<\/a><\/p>\n-l<\/code>\u00a0flag is used to the default scale (digits after the decimal point) to\u00a020<\/strong>, for example:<\/p>\n$ echo '12\/5 | bc'\r\n$ echo '12\/5 | bc -l'\r\n<\/pre>\n
<\/a><\/p>\n4. Using Awk Command<\/h3>\n
$ awk 'BEGIN { a = 6; b = 2; print \"(a + b) = \", (a + b) }'\r\n$ awk 'BEGIN { a = 6; b = 2; print \"(a - b) = \", (a - b) }'\r\n$ awk 'BEGIN { a = 6; b = 2; print \"(a * b) = \", (a * b) }'\r\n$ awk 'BEGIN { a = 6; b = 2; print \"(a \/ b) = \", (a \/ b) }'\r\n$ awk 'BEGIN { a = 6; b = 2; print \"(a % b) = \", (a % b) }'\r\n<\/pre>\n<\/a><\/p>\n5. Using factor Command<\/h3>\n
$ factor 10\r\n$ factor 127\r\n$ factor 222\r\n$ factor 110 \r\n<\/pre>\n
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