[qt, cmd] Document & fix some inconsistencies with command line arguments (#3104)

- documents command line arguments
- allows you to specify files starting with `-`
Signed-off-by: lizzie lizzie@eden-emu.dev

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3104
Reviewed-by: Caio Oliveira <caiooliveirafarias0@gmail.com>
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

1 files changed, 22 insertions, 0 deletions

diff --git a/docs/user/CommandLine.md b/docs/user/CommandLine.md
new file mode 100644
index 0000000000..4b3a5bdf58
--- /dev/null
+++ b/docs/user/CommandLine.md
@@ -0,0 +1,22 @@
+# User Handbook - Command Line
+
+There are two main applications, an SDL2 based app (`eden-cli`) and a Qt based app (`eden`); both accept command line arguments.
+
+## eden
+- `./eden <path>`: Running with a single argument and nothing else, will make the emulator look for the given file and load it, this behaviour is similar to `eden-cli`; allows dragging and dropping games into the application.
+- `-g <path>`: Alternate way to specify what to load, overrides. However let it be noted that arguments that use `-` will be treated as options/ignored, if your game, for some reason, starts with `-`, in order to safely handle it you may need to specify it as an argument.
+- `-f`: Use fullscreen.
+- `-u <number>`: Select the index of the user to load as.
+- `-qlaunch`: Launch QLaunch.
+- `-setup`: Launch setup applet.
+
+## eden-cli
+- `--debug/-d`: Enter debug mode, allow gdb stub at port `1234`
+- `--config/-c`: Specify alternate configuration file.
+- `--fullscreen/-f`: Set fullscreen.
+- `--help/-h`: Display help.
+- `--game/-g`: Specify the game to run.
+- `--multiplayer/-m`: Specify multiplayer options.
+- `--program/-p`: Specify the program arguments to pass (optional).
+- `--user/-u`: Specify the user index.
+- `--version/-v`: Display version and quit.