You can use the `wc` command in Linux to count the number of lines, words, and characters in a text file. To specifically count the number of characters you can use the `-m` option. Here is an example: ```bash wc -m filename.txt ``` In this command, `wc` stands for 'word count' and `-m` tells it to count characters. Replace 'filename.txt' with the name of your file. Explanation: - `wc`: The command reads either standard input or a list of files and generates one or more of the following statistics: newline count, word count, and byte count. If a list of files is provided, `wc` generates a statistic for each file and then totals the numbers and produces the same statistics for the total. - `-m`: Prints the character counts. So, for example, if you have a file called 'example.txt', and you want to find out how many characters it contains, you would type: ```bash wc -m example.txt ``` After hitting enter, `wc` will print the number of characters in 'example.txt' to the terminal. It's an extremely handy tool that comes with virtually all unix-like operating systems, or available for installation on those where it doesn't.