Example program won't run; undefined debug symbol

[JohnBabrick]

I am building in eclipse the receive example program and get this error when I try to run it:

/home/johann/workspace/testSerial/Debug/testSerial: symbol lookup error: /home/johann/workspace/testSerial/Debug/testSerial: undefined symbol: _ZN9LibSerial12SerialStream4OpenENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESt13_Ios_Openmode

I have added the -lserial and the -pthread and the appropriate lib and include directories. I built the code from source on the latest from github under Ubuntu 15.04. Any ideas?

include

include

include

include

int main( int argc, char\ argv ) { // // Open the serial port. // using namespace LibSerial ; SerialStream serial_port ; serial_port.Open( "/dev/ttyUSB0" ) ; if ( ! serial_port.good() ) { std::cerr << "[" << FILE << ":" << LINE << "] " << "Error: Could not open serial port." << std::endl ; exit(1) ; } // // Set the baud rate of the serial port. // serial_port.SetBaudRate( SerialStreamBuf::BAUD_115200 ) ; if ( ! serial_port.good() ) { std::cerr << "Error: Could not set the baud rate." << std::endl ; exit(1) ; } // // Set the number of data bits. // serial_port.SetCharSize( SerialStreamBuf::CHAR_SIZE_8 ) ; if ( ! serial_port.good() ) { std::cerr << "Error: Could not set the character size." << std::endl ; exit(1) ; } // // Disable parity. // serial_port.SetParity( SerialStreamBuf::PARITY_NONE ) ; if ( ! serial_port.good() ) { std::cerr << "Error: Could not disable the parity." << std::endl ; exit(1) ; } // // Set the number of stop bits. // serial_port.SetNumOfStopBits( 1 ) ; if ( ! serial_port.good() ) { std::cerr << "Error: Could not set the number of stop bits." << std::endl ; exit(1) ; } // // Turn off hardware flow control. // serial_port.SetFlowControl( SerialStreamBuf::FLOW_CONTROL_NONE ) ; if ( ! serial_port.good() ) { std::cerr << "Error: Could not use hardware flow control." << std::endl ; exit(1) ; } // // Do not skip whitespace characters while reading from the // serial port. // // serial_port.unsetf( std::ios_base::skipws ) ; // // Wait for some data to be available at the serial port. // while( serial_port.rdbuf()->in_avail() == 0 ) { usleep(100) ; } // // Keep reading data from serial port and print it to the screen. // while( serial_port.rdbuf()->in_avail() > 0 ) { char next_byte; serial_port.get(next_byte); std::cerr << std::hex << static_cast(next_byte) << " "; usleep(100) ; } std::cerr << std::endl ; return EXIT_SUCCESS ; }

[crayzeewulf]

Can you please show the compiler command that you used to build your example program (you might have to copy this from Eclipse window)? Also, what is the output of the following command:

ldd path_to_your_executable

(Replace path_to_your_executable with the path to your program's executable, of course).

[JohnBabrick]

I think I found my problem.

I originally installed libserial from Ubuntu's repository which installed it to /usr/lib/x86_64-linux-gnu, then, when I couldn't get things to work correctly I tried removing it and then installing it by building the source from github. That installation put it in /usr/local/lib. However, apparently the remove did not remove it from /usr/lib/x86_64-linux-gnu and now I had versions in both /usr/lib/x86_64-linux-gnu (didn't work) and /usr/local/lib (does work). ldd showed a link to the /usr/lib/x86_64-linux-gnu.

The solution was to manually remove from /usr/lib and run ldconfig. For what it's worth I learned a bit about ldd, ldconfig and ld.so today. Thanks for your help, I look forward to using your code to access a ham radio's serial port.

[crayzeewulf]

Excellent! Glad to hear that you found the source of the problem. Thanks for the update.