Unix 'cat' Command Implemented In Swift Without Foundation

bridge.h

#import <stdio.h>

cat.swift

let byLine = { (file : UnsafeMutablePointer<FILE>) in
    anyGenerator({ () -> String? in
        var input = UnsafeMutablePointer<Int8>()
        var lim = 0
        return getline(&input, &lim, file) > 0 ? String.fromCString(input) : nil
    })
}

let cat = {(fd: UnsafeMutablePointer<FILE>) -> Void in
    for line in byLine(fd) {
        print(line, appendNewline: false)
    }
}

if Process.arguments.count == 1 {
    cat(stdin)
} else {
    Process.arguments[1..<Process.arguments.count].map { f -> Void in
        let fd = fopen(f, "r")
        cat(fd)
        fclose(fd)
    }
}

Makefile

SDKPATH = $(shell xcrun --show-sdk-path --sdk macosx)
CBRIDGEHEADER = bridge.h
TARGETS := cat

.PHONY : all $(TARGETS)

all: $(TARGETS)

$(TARGETS):
	swiftc -sdk $(SDKPATH) $@.swift -import-objc-header $(CBRIDGEHEADER) -o $@