Communicate whether file transfers were completed

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 53 insertions, 0 deletions

diff --git a/common.c b/common.c
new file mode 100644
index 0000000..5379f89
--- /dev/null
+++ b/common.c
@@ -0,0 +1,53 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+void
+copy_file(int destfd, const char *destfname, int srcfd, const char *srcfname, int *okp)
+{
+	char buf[BUFSIZ];
+	ssize_t r, w, p, ok_off;
+	size_t read_off;
+
+	if (okp) {
+		*okp = 0;
+		ok_off = 1;
+		read_off = 0;
+	} else {
+		ok_off = 0;
+		read_off = 1;
+		buf[0] = 0;
+	}
+
+	for (;;) {
+		r = read(srcfd, &buf[read_off], sizeof(buf) - read_off);
+		if (r <= 0) {
+			if (!r)
+				break;
+			fprintf(stderr, "%s: read %s: %s", argv0, srcfname, strerror(errno));
+			exit(1);
+		}
+
+		if (r == ok_off) { /* Only possible if okp != NULL */
+			*okp = 1;
+			break;
+		}
+
+		r += (ssize_t)read_off;
+		for (p = ok_off; p < r; p += w) {
+			w = write(destfd, buf, (size_t)(r - p));
+			if (r <= 0) {
+				fprintf(stderr, "%s: write %s: %s", argv0, destfname, strerror(errno));
+				exit(1);
+			}
+		}
+	}
+
+	if (!okp) {
+		w = write(destfd, buf, 1);
+		if (r <= 0) {
+			fprintf(stderr, "%s: write %s: %s", argv0, destfname, strerror(errno));
+			exit(1);
+		}
+	}
+}