diff --git a/src/main.d b/src/main.d
index 4b54157..2eddf43 100644
--- a/src/main.d
+++ b/src/main.d
@@ -23,9 +23,6 @@ import std.getopt;
 import sums;
 
 int main (string[] parArgs) {
-	if (parArgs.length == 1)
-		return 0;
-
 	const auto cwd = getcwd();
 	const auto working_dir = cwd ~ (cwd[$-1] == '/' ? "" : "/");
 
diff --git a/src/sums.d b/src/sums.d
index d64d29e..3284644 100644
--- a/src/sums.d
+++ b/src/sums.d
@@ -26,6 +26,8 @@ import std.format;
 import std.array : appender;
 import std.path;
 
+private const string g_out_format = "%s  %s";
+
 private void writeError (string parFile, string parMessage) {
 	stderr.writefln("tigersum: %s: %s", parFile, parMessage);
 }
@@ -34,7 +36,7 @@ private void writeWarning (string parMessage) {
 	writeError("WARNING", parMessage);
 }
 
-void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, string parFileMode, bool parBsdStyle) {
+private void calculateSumsOnFiles (in string[] parFiles, in string parCWD, bool parTiger2, string parFileMode, bool parBsdStyle) {
 	ulong[] read_buff = new ulong[READ_BUFF_BLOCKS * 64 / ulong.sizeof];
 
 	foreach (file_name; parFiles) {
@@ -54,7 +56,7 @@ void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, stri
 				writefln("tiger (%s) = %s", file_name, hash);
 			}
 			else {
-				writefln("%s  %s", hash, file_name);
+				writefln(g_out_format, hash, file_name);
 			}
 		}
 		else {
@@ -63,6 +65,20 @@ void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, stri
 	}
 }
 
+private void calculateSumsOnStdIn (bool parTiger2, bool parBsdStyle) {
+	const string hash = tigerToString(getTiger(stdin, parTiger2));
+	writefln(g_out_format, hash, "-");
+}
+
+void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, string parFileMode, bool parBsdStyle) {
+	if (parFiles.empty || parFiles.length == 1 && parFiles[0] == "-") {
+		calculateSumsOnStdIn(parTiger2, parBsdStyle);
+	}
+	else {
+		calculateSumsOnFiles(parFiles, parCWD, parTiger2, parFileMode, parBsdStyle);
+	}
+}
+
 bool checkSums (in string parFile, in string parRoot, bool parTiger2, string parFileMode) {
 	File curr_list = File(parFile, "r");
 	bool ret_val = true;
diff --git a/src/tiger.d b/src/tiger.d
index 13806cf..4cc9923 100644
--- a/src/tiger.d
+++ b/src/tiger.d
@@ -53,26 +53,19 @@ public ulong[3] getTiger (ref File parData, bool parV2, char[] parBuffer) {
 	assert((cast(size_t)parBuffer.ptr & cast(size_t)(ulong.alignof - 1)) == 0);
 
 	ulong[3] retval;
-	auto data_left = parData.size;
-	const auto buff_length = 64 * READ_BUFF_BLOCKS;
+	char[] data, prev_data;
+	ulong real_length = 0;
 
 	tiger_init(retval);
-	while (data_left >= buff_length) {
-		parData.rawRead(parBuffer);
-		tiger_chunk(parBuffer.ptr, buff_length, retval);
-		data_left -= buff_length;
+	while (!(data = parData.rawRead(parBuffer)).empty) {
+		tiger_chunk(data.ptr, data.length, retval);
+		real_length += data.length;
+		prev_data = data;
 	}
 
 	const char padding = (parV2 ? 0x80 : 0x01);
-	if (data_left) {
-		parData.rawRead(parBuffer[0 .. data_left]);
-		const ulong proc_length = data_left & ~0x3fUL;
-		tiger_chunk(parBuffer.ptr, proc_length, retval);
-		tiger_last_chunk(parBuffer.ptr + proc_length, data_left - proc_length, parData.size, retval, padding);
-	}
-	else {
-		tiger_last_chunk(null, 0, parData.size, retval, padding);
-	}
+	const ulong proc_length = prev_data.length & ~0x3fUL;
+	tiger_last_chunk(prev_data.ptr + proc_length, prev_data.length - proc_length, real_length, retval, padding);
 
 	return retval;
 }