# style50 `style50` is a command-line tool with which you can check your code for consistency with [CS50's style guide](../style/c/) (for C). If your code isn't styled consistently, `style50` will summarize the changes you should make to your code, as by highlighting in green characters you should add and highlighting in red characters you should delete. For instance, consider the code below, wherein the call to `printf` isn't properly indented. ```text #include int main(void) { printf("hello, world\n"); } ``` Given that code as input, `style50` will output

#include <stdio.h>

int main(void)
{
    printf("hello, world\n");
}

wherein highlighted are four spaces that should be added for style's sake. On the other hand, consider the code below, wherein the curly braces are unnecessarily indented. ```text #include int main(void) { printf("hello, world\n"); } ``` Given that code as input, `style50` will output

#include <stdio.h>

int main(void)
    {
    printf("hello, world\n");
    }

wherein highlighted are four spaces that should be deleted for style's sake. ## Usage To check your code's style, execute ```text style50 file ``` where `file` is the (path to some) file whose style you'd like to check. ### Modes By default, `style50` operates in [`character`](#character) mode, but you can specify other modes with `-o` or `--output`. Consider the (poorly styled) file below, `hello.c`, for a look at these modes. ```text #include int main(void) { printf("hello, world\n"); } ``` #### `character` In `character` mode, `style50` compares its input against CS50's style guide character by character. Were you to run ```text style50 --output character hello.c ``` or just ```text style50 -o character hello.c ``` or even just ```text style50 hello.c ``` you would see the below.

#include <stdio.h>

int main(void)
{\n
    {\n
    printf("hello, world\n");
    }

#### `split` In `split` mode, `style50` displays its input and output side by side. Were you to run ```text style50 --output split hello.c ``` or just ```text style50 -o split hello.c ``` you would see the below.

#include <stdio.h>               #include <stdio.h>

int main(void)                   int main(void)
    {                            {
printf("hello, world\n");            printf("hello, world\n");
    }                            }

#### `unified` In `unified` mode, `style50` displays its output line by line, akin to [`git-diff`](https://git-scm.com/docs/git-diff). Were you to run ```text style50 --output unified hello.c ``` or just ```text style50 -o unified hello.c ``` you would see the below.

  #include <stdio.h>

  int main(void)
-     {
+ {
- printf("hello, world\n");
+     printf("hello, world\n");
-     }
+ }

## Installation `style50` is already installed for you in [CS50 IDE](https://ide.cs50.io/), so no need to install it yourself; simply use it as directed! If you'd like to install `style50` on your own Mac or PC, so that you can check your code's style without using CS50 IDE, you'll need a command-line environment: - If running Linux or the like, you already have one! Open a terminal window in your usual way. - If running Mac OS, you already have one! Open **Applications > Utilities > Terminal**. - If running Windows, you'll need to install the [Windows Subsystem for Linux](https://msdn.microsoft.com/commandline/wsl/about), which is only supported on Windows 10. Once installed, [run `bash`](https://blogs.windows.com/buildingapps/2016/03/30/run-bash-on-ubuntu-on-windows/). To install `style50` within that command-line environment: 1. [Install Python](https://www.python.org/downloads/) 2.7 or higher, if not already installed. 1. Install `pip`, as via ```text sudo easy_install pip ``` if not already installed. 1. Execute ```text sudo pip3 install style50 ``` to install `style50` itself. 1. Install [Artistic Style 3.0](http://astyle.sourceforge.net/). If running a Debian-based operating system (e.g., Ubuntu Linux), simply run ```text apt-get update apt-get install astyle ``` to install CS50's own compiled version of `astyle`. ## Upgrading Execute ```text sudo pip install --upgrade style50 ``` to upgrade `style50`, once installed. ## Source Code