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.

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.