1 files changed, 75 insertions, 0 deletions
diff --git a/tool_select.h b/tool_select.h
new file mode 100644
index 0000000..7071718
--- /dev/null
+++ b/tool_select.h
@@ -0,0 +1,75 @@
+#ifndef TOOLBOX_SELECT_H
+#define TOOLBOX_SELECT_H
+
+#include "tools.h"
+
+#include <sys/types.h>
+
+/* cTBSelect provides an interface for polling UNIX-like file descriptors. */
+
+class cTBSelect {
+private:
+	int    m_MaxFiled;
+
+	fd_set m_Rfds;
+	fd_set m_Wfds;
+
+public:
+	cTBSelect(void);
+	virtual ~cTBSelect();
+
+	/* Clear() resets the object for use in a new Select() call. All file 
+	   descriptors and their previous states are invalidated. */
+	virtual void Clear(void);
+
+	/* Add() adds a file descriptor to be polled in the next Select() call.
+	   That call polls if the file is readable if Output is set to false, 
+	   writeable otherwise. */
+	virtual bool Add(int Filed, bool Output = false);
+
+	/* Select() polls all descriptors added by Add() and returns as soon as
+	   one of those changes state (gets readable/writeable), or after
+	   TimeoutMs milliseconds, whichever happens first. It returns the number
+	   of filedescriptors that have changed state. On error, -1 is returned
+	   and errno is set appropriately. */
+	virtual int Select(uint TimeoutMs);
+
+	/* Select() polls all descriptors added by Add() and returns as soon as
+	   one of those changes state (gets readable/writeable). It returns the 
+	   number of filedescriptors that have changed state. On error, -1 is 
+	   returned and errno is set appropriately. */
+	virtual int Select(void);
+
+	/* CanRead() returns true if the descriptor has changed to readable during
+	   the last Select() call. Otherwise false is returned. */
+	virtual bool CanRead(int FileNo) const;
+
+	/* CanWrite() returns true if the descriptor has changed to writeable 
+	   during the last Select() call. Otherwise false is returned. */
+	virtual bool CanWrite(int FileNo) const;
+};
+
+inline void cTBSelect::Clear(void) {
+	FD_ZERO(&m_Rfds);
+	FD_ZERO(&m_Wfds);
+	m_MaxFiled = -1;
+}
+
+inline bool cTBSelect::Add(int Filed, bool Output /* = false */) {
+	if (Filed < 0) return false;
+	FD_SET(Filed, Output ? &m_Wfds : &m_Rfds);
+	if (Filed > m_MaxFiled) m_MaxFiled = Filed;
+	return true;
+}
+
+inline bool cTBSelect::CanRead(int FileNo) const {
+	if (FileNo < 0) return false;
+	return FD_ISSET(FileNo, &m_Rfds);
+}
+
+inline bool cTBSelect::CanWrite(int FileNo) const {
+	if (FileNo < 0) return false;
+	return FD_ISSET(FileNo, &m_Wfds);
+}
+
+#endif // TOOLBOX_SELECT_H