#include <stdlib.h> #include <string.h> #include <unistd.h> #include <errno.h> #define __USE_GNU #include <sys/utsname.h> int getdomainname(char *name, size_t len) { struct utsname uts; if (name == NULL) { __set_errno(EINVAL); return -1; } if (uname(&uts) == -1) return -1; if (strlen(uts.domainname)+1 > len) { __set_errno(EINVAL); return -1; } strcpy(name, uts.domainname); return 0; }