You can count the characters in a file in Linux using a few different methods, let's talk about two of them. **Method 1:** Use `wc` (word count) command with `-m` option which counts the number of characters. ``` wc -m filename ``` `filename` is the name of your file. The output will be the number of characters along with the filename. **Method 2:** Use `cat` command with `wc -m`: ``` cat filename | wc -m ``` This will simply output the number of characters. Brief explanation of the commands used: - `wc` (short for word count) is a command in Unix and Unix-like operating systems that prints newline, word, and byte counts for each input file, or a total if more than one input file is specified. - `-m` option tells `wc` to count characters. - `cat` command concatenates and displays files. - `|` is a pipeline which takes the output of one command (left of `|`) as input to the next one (right of `|`). Please note that these commands will count newline characters as well. For more detailed guide on how to use these commands, refer to their man pages (manual pages) by typing `man wc` or `man cat` in the terminal.