1 files changed, 14 insertions, 0 deletions
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 48884d5208..90856d67e5 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -961,3 +961,17 @@ test_env () {
 		done
 	)
 }
+
+# Read up to "$1" bytes (or to EOF) from stdin and write them to stdout.
+test_copy_bytes () {
+	perl -e '
+		my $len = $ARGV[1];
+		while ($len > 0) {
+			my $s;
+			my $nread = sysread(STDIN, $s, $len);
+			die "cannot read: $!" unless defined($nread);
+			print $s;
+			$len -= $nread;
+		}
+	' - "$1"
+}