an io library shouldnt have race conditions

libio/Makefile

@@ -1,2 +0,0 @@
-libio.o: libio.c libio.h
-	$(CC) -c -o libio.o libio.c

libio/libio.c

@@ -1,97 +0,0 @@
-#include <unistd.h>
-#include "libio.h"
-
-/* Backups of standard library systems for the odd scenario where there is no
- * standard library but there is the write(2) system call. */
-
-#if defined USE_SYSTEM_STRING_H
-#	include <string.h>
-#	define _strlen strlen
-#else
-/* Normally in <string.h> */
-static int
-_strlen(char *s){
-	int i;
-
-	for(i = 0; s[i] != '\0'; ++i);
-
-	return i;
-}
-#endif
-
-#if defined USE_SYSTEM_CTYPE_H
-#	include <ctype.h>
-#	define _isdigit isdigit
-#else
-/* Normally in <ctype.h> */
-static int
-_isdigit(int c){
-	return c >= '0' && c <= '9';
-}
-#endif
-
-/* Wrappers around write(2) */
-static int _write(int fd, char *s, int n);
-static int _write1(int fd, int c);
-
-/* Wrapper around write(2) - keeps re-running write(2) until the operation
- * succeeds in full. Usually unnecessary but still good. */
-static int
-_write(int fd, char *s, int n){
-	int i;
-
-	for(
-		i = 0;
-		i < n;
-		i += write(fd, s+i, n-i)
-	);
-
-	return i;
-}
-
-/* For writing a single character. To optimize for speed, functions should
- * allocate a buffer and add to that buffer before write(2)ing the buffer out
- * in a single system call. However sometimes cheap tricks are as effective. */
-static int
-_write1(int fd, int c){
-	while(write(fd, &c, 1) != 1);
-	return 1;
-}
-
-int
-fdprint(int fd, char *s){
-	return _write(fd, s, _strlen(s));
-}
-
-int
-fdputs(int fd, char *s){
-	int i;
-	int r;
-
-	i = _strlen(s);
-
-	/* RACE CONDITION */
-	/* This leaves s as an invalid string while the write(2) syscall is
-	 * performed, which can take a non-trivial amount of time. This
-	 * implementation is unsuitable when s is shared between threads or
-	 * whatever the CS term for that is. */
-	s[i] = '\n';
-	r = _write(fd, s, i + 1);
-	s[i] = '\0';
-
-	return r;
-}
-
-/* Another possible implementation would take char **s and leave *s at the next
- * non-digit. But that's less simple; just while(isdigit(*s)) ++s;. */
-unsigned int
-parse_uint(char *s){
-	unsigned int r;
-	for(
-		r = 0;
-		_isdigit(*s);
-		r = r * 10 + *s - '0',
-			++s
-	);
-	return r;
-}

libio/libio.h

@@ -1,7 +0,0 @@
-#ifndef _LIBIO_H
-#	define _LIBIO_H
-int fdprint(int fd, char *s);
-int fdputd(int fd, int d);
-int fdputs(int fd, char *s);
-unsigned int parse_uint(char *s);
-#endif /* ifndef _LIBIO_H */