How to check if a file's size is greater than a certain value in Bash

Question

How do I achieve the following goal:

• I need to check the size of a file
• Then compare this file size to a fixed number using an if condition and corresponding conditional statement

So far, I have the following:

#!/bin/bash  # File to consider FILENAME=./testfile.txt  # MAXSIZE is 5 MB MAXSIZE = 500000  # Get file size FILESIZE=$(stat -c%s "$FILENAME") # Checkpoint echo "Size of $FILENAME = $FILESIZE bytes."  # The following doesn't work if [ (( $FILESIZE > MAXSIZE)) ]; then     echo "nope" else     echo "fine" fi 

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With this code, I can get the file name in the variable $FILESIZE, but I am unable to compare it with a fixed integer value.

#!/bin/bash filename=./testfile.txt maxsize=5 filesize=$(stat -c%s "$filename") echo "Size of $filename = $filesize bytes."  if (( filesize > maxsize )); then     echo "nope" else     echo "fine" fi 

Answer 1

A couple of syntactic issues.

1. The variable definitions in Bash do not take spaces. It should have been MAXSIZE=500000, without spaces.
2. The way comparison operation is done is incorrect. Instead of if [ (( $FILESIZE > MAXSIZE)) ];, you could very well use Bash’s own arithmetic operator alone and skip the [ operator to just if (( FILESIZE > MAXSIZE)); then

If you are worried about syntax issues in your script, use ShellCheck to syntax check your scripts and fix the errors as seen from it.

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As a general coding practice, use lowercase user-defined variables in Bash to avoid confusing them with the special environment variables which are interpreted for different purposes by the shell (e.g., $HOME and $SHELL).