Merge pull request #73 from markus-oberhumer/safe-read-write

1 files changed, 55 insertions, 0 deletions

diff --git a/util.c b/util.c
index 42e3d98..00f5b78 100644
--- a/util.c
+++ b/util.c
@@ -368,3 +368,58 @@ int bfs_minor(dev_t dev) {
 	return dev & 0xFF;
 #endif
 }
+
+ssize_t safe_read(int fd, void *buf, size_t nbytes) {
+	for (;;) {
+		ssize_t ret = read(fd, buf, nbytes);
+		if (ret < 0 && errno == EINTR) {
+			continue;
+		}
+		return ret;
+	}
+}
+
+ssize_t safe_read_all(int fd, void *buf, size_t nbytes) {
+	size_t count = 0;
+	for (;;) {
+		ssize_t ret = read(fd, (char *)buf + count, nbytes - count);
+		if (ret < 0 && errno == EINTR) {
+			continue;
+		}
+		if (ret < 0) {
+			return ret; // always return error < 0
+		}
+		count += ret;
+		if (ret == 0 || count == nbytes) { // EOF or success
+			return count;
+		}
+	}
+}
+
+ssize_t safe_write(int fd, const void *buf, size_t nbytes) {
+	for (;;) {
+		ssize_t ret = write(fd, buf, nbytes);
+		if (ret < 0 && errno == EINTR) {
+			continue;
+		}
+		return ret;
+	}
+}
+
+ssize_t safe_write_all(int fd, const void *buf, size_t nbytes)
+{
+	size_t count = 0;
+	for (;;) {
+		ssize_t ret = write(fd, (const char *)buf + count, nbytes - count);
+		if (ret < 0 && errno == EINTR) {
+			continue;
+		}
+		if (ret < 0) {
+			return ret; // always return error < 0
+		}
+		count += ret;
+		if (ret == 0 || count == nbytes) { // EOF (should never happen with write) or success
+			return count;
+		}
+	}
+}