# kcore
**kcore** is the foundation for the rest of libk. it defines types and structs that are needed by every program, and provides the stub that launches a program's "entry" function.
## entry
when using libk, your program's entry point will not be the `int main(int,char**)` function that libc opens into. libk will call the function `stat entry(kenv)` instead. like libc, the value returned by `entry` will be returned to the host platform.
## types
kcore contains fixed-width integer types (in <k/type.h>). note that the availability of each depends on your platform; compilation will fail if e.g. you try to use a u64 or a u128 on a 32-bit platform, so where exact lengths are not required, you may wish to use the built-in C types instead.
* `u8` - an unsigned 8-bit integer
* `s8` - a signed 8-bit integer
* `u16` - an unsigned 16-bit integer
* `s16` - a signed 16-bit integer
* `u32` - an unsigned 32-bit integer
* `s32` - a signed 32-bit integer
* `u64` - an unsigned 64-bit integer
* `s64` - a signed 64-bit integer
* `u128` - an unsigned 128-bit integer
* `s128` - a signed 128-bit integer
* `word` - an unsigned integer of platform word-length (e.g. 32 bits on x86.32; 64 on x86.64)
* `sword` - a signed integer of platform word-length (e.g. 32 bits on x86.32; 64 on x86.64)
* `stat` - the type of process return values expected by the platform (usually u8 on linux)
### struct kenv
`kenv` is a struct that encompasses the environment the program was launched in.
* `kiochan std` - a stereo IO channel for reading and writing to and from stdout.
* `kiochan err` - a mono IO channel for writing to stderr.
* `kvar* vars` - a pointer into the program's environment
### struct kvar
`kvar` is a struct that abstracts over platform environment variables.
* `kstr name` - the name of an environment variable
* `kstr val` - the value of an environment variable
* `char* platform` - a pointer into the platform's underlying representation