Implementation of [SRFI 170](https://srfi.schemers.org/srfi-170/srfi-170.html)
POSIX API using [(foreign c)](https://git.sr.ht/~retropikzel/foreign-c).

Currently only supports Linux.

Uncommented things here are implemented.

    ;;;;posix-error?
    ;;;;posix-error-name
    ;;;;posix-error-message
    ;;;;open-file
    ;;;;fd->port
    create-directory
    ;;;;create-fifo
    create-hard-link
    create-symlink
    ;;;;read-symlink
    ;;;;rename-file
    delete-directory
    ;;;;set-file-owner
    ;;;;set-file-times
    ;;;;truncate-file
    file-info
    file-info?
    ;;;;file-info:device
    ;;;;file-info:inode
    ;;;;file-info:mode
    ;;;;file-info:nlinks
    ;;;;file-info:uid
    ;;;;file-info:gid
    ;;;;file-info:rdev
    ;;;;file-info:size
    ;;;;file-info:blksize
    ;;;;file-info:blocks
    ;;;;file-info:atime
    ;;;;file-info:mtime
    ;;;;file-info:ctime
    file-info-directory?
    ;;;;file-info-fifo?
    ;;;;file-info-symlink?
    ;;;;file-info-regular?
    ;;;;file-info-socket?
    ;;;;file-info-device?
    set-file-mode
    directory-files
    ;;;;make-directory-files-generator
    open-directory
    read-directory
    close-directory
    real-path
    ;;;;file-space
    temp-file-prefix
    create-temp-file
    call-with-temporary-filename
    ;;;;umask
    ;;;;set-umask!
    current-directory
    set-current-directory!
    pid
    ;;;;nice
    user-uid
    user-gid
    user-effective-uid
    user-effective-gid
    user-supplementary-gids
    user-info
    user-info?
    user-info:name
    user-info:uid
    user-info:gid
    user-info:home-dir
    user-info:shell
    user-info:full-name
    ;;;;user-info:parsed-full-name
    group-info
    group-info?
    group-info:name
    group-info:gid
    ;;;;posix-time
    ;;;;monotonic-time
    set-environment-variable!
    delete-environment-variable!
    ;;;;terminal?