Hi This is in tclcl.h file. #include <sys/types.h> #include <string.h> #include <tcl.h> extern "C" { #include <otcl.h> } #include "tclcl-config.h" #include "tracedvar.h" What does extern "C" ... mean? Thanks in advance. -- Xia YinChu 夏寅初 @ ShangHai JiaoTong University - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs