...p () Thread safety MT-Safe VERSIONS These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls. STANDARDS POSIX.1-2008. HISTORY POSIX.1-2001. The ioctls appeared in …...p () Thread safety MT-Safe VERSIONS These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls. STANDARDS POSIX.1-2008. HISTORY POSIX.1-2001. The ioctls appeared in …