Getting error number returned by recv function

Question

How can I get the error number or error string returned by the recv() in socket communication, recv() returns -1 as read size which means some error has occurred. I want to know the specific reason for the error. so how can I get that.

Answer 1

You need to include errno.h and use the errno global variable to check the last error code. Also, you can use strerror() to print a locale aware string explaining the error.

Example

#include <errno.h>

ssize_t size;

if ((size = recv( ... )) == -1)
{
    fprintf(stderr, "recv: %s (%d)\n", strerror(errno), errno);
}