split some io routines into separate file

ioutil.c

@@ -0,0 +1,67 @@
+#include <stdint.h>
+#include <string.h>
+#include "types.h"
+#include "ioutil.h"
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int writeall(FH fd,const u8 *data,size_t len)
+{
+	ssize_t wrote;
+	while (len) {
+		wrote = write(fd,data,len);
+		if (wrote == -1) {
+			if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+				continue;
+			return -1;
+		}
+		len -= wrote;
+		data += wrote;
+	}
+	return 0;
+}
+
+FH createfile(const char *path,int secret)
+{
+	int fd;
+	do {
+		fd = open(path,O_WRONLY | O_CREAT | O_TRUNC,secret ? 0600 : 0666);
+		if (fd == -1) {
+			if (errno == EINTR)
+				continue;
+			return -1;
+		}
+	} while (0);
+	return fd;
+}
+
+int closefile(FH fd)
+{
+	int cret;
+	do {
+		cret = close(fd);
+		if (cret == -1) {
+			if (errno == EINTR)
+				continue;
+			return -1;
+		}
+	} while (0);
+	return 0;
+}
+
+int writetofile(const char *path,const u8 *data,size_t len,int secret)
+{
+	FH fd = createfile(path,secret);
+	int wret = writeall(fd,data,len);
+	int cret = closefile(fd);
+	if (cret == -1)
+		return -1;
+	return wret;
+}
+
+int createdir(const char *path,int secret)
+{
+	return mkdir(path,secret ? 0700 : 0777);
+}