This file contains a list of things that are important to take note of when using WallShell.

C99

The entire core of WallShell is written with strict ISO C99 adherence in mind. It uses your systems implementation of threads and console control.

Note on Streams

• stdin is required for input on windows and POSIX.
  • The ability to change stdin is mostly meant for freestanding environments.
  • You have to define CUSTOM_CONSOLE_SETUP and everything that it includes.
    • You can do this on Windows and POSIX, but you will have to deal with console setup yourself. WallShell expects mostly raw terminal input, look through the source to see what this implies.
• stdout is used as default output, you can redirect it.
  • You can also redirect error output, default stderr, but currently it's not being used.
• Multiple things writing/reading from the same streams.
  • If multiple things (other than or including WallShell) are writing to the same stream, things may be out of order or out of place. This should not affect thread-safety, although if you are reading from the same stream you're writing to, make sure to sanitize input.

"Counts" are very important

• For any field in a struct that is a "count", like aliases_count, are expected to behave like strlen. It's the total count, not the indexes.
• WallShell will attempt to access any part of the array as long as our "count" says that it's there. If count is wrong, it's undefined behavior (although it'll probably cause a segfault of some type).

Using WallShell in C++

WallShell is written in ISO C, so it's compatible without modifications. A few things need to noted though:

• Commands are expected to be statically defined.
  • It's possible to use class methods as commands, but for C to be happy with them, you have to statically define them.
  • If this isn't possible, create a function outside the class specifically for WallShell.
• All functions passed to WallShell MUST be marked extern "C".
  • This does not mean that those functions cannot contain C++ code. extern "C" simply disables name mangling for that function.
• Be careful with strings.
  • WallShell, being written in C, of course wants null terminated strings of char* type.
  • If using std::string, utilize the c_str() function when needed.