server/syncrw.c

#include <unistd.h>
#include <errno.h>

int sync_read(int fd, void *buffer, size_t count) {
	char *p = buffer;
	do {
		int s = read(fd, p, count);
		if(s < 0) {
			if(errno == EINTR) continue;
			return -1;
		}
		if(!s) return p - (char *)buffer;
		count -= s;
		p += s;
	} while(count > 0);
	return p - (char *)buffer;
}

int sync_write(int fd, const void *buffer, size_t count) {
	const char *p = buffer;
	do {
		int s = write(fd, p, count);
		if(s < 0) {
			if(errno == EINTR) continue;
			return -1;
		}
		if(!s) return p - (char *)buffer;
		count -= s;
		p += s;
	} while(count > 0);
	return p - (char *)buffer;
}