Is there a way to round a number in Bash?
Bash only evaluates expressions with non-floating point numbers. So there is no built-in function for rounding up or down floating point numbers. External commands like bc or awk or perl can be used to round numbers as needed. I have tried several methods.
How can I round up a number in Unix?
Unix commandline tool awk can also be used to round up or down numbers. awk has built in functions like int () to cast numbers as integers. Here is an example. See? The precision part is always dropped.
How can I do Division with variables in a Linux shell?
The default shell on most Linux distributions is Bash. In Bash, variables must use a dollar sign prefix for parameter expansion. For example: Of course, Bash also has arithmetic operators and a special arithmetic expansion syntax, so there’s no need to invoke the expr binary as a separate process.
What’s the difference between rounding up and rounding down?
Note that rounding up to nearest integer is equivalent to adding .5 and taking the floor, or rounding down (for positive numbers). Also, the scale factor is applied at the time of operation; so (these are bc commands, you can paste them into your terminal):
How to round up a float point in shell?
You can just use printf: To extend Tim’s answer, you can write a shell helper function round $ {FLOAT} $ {PRECISION} for this: A little trick is to add 0.0005 to your input, this way you will have your number round up correctly.
Is there a way to do math calculations in Bash?
The legacy way to do math calculations with integer, and only integer, has been for a long time to use the expr command line. Though, this method can be slow as expr is a binary, not a shell builtin. It will fork a new process which is not ideal in a large for-loop. Also, the expr behavior may vary between systems depending on the implementation.