_SYS_NAMELEN
char sysname[_SYS_NAMELEN]; /* Name of the OS */
char nodename[_SYS_NAMELEN]; /* Name of this node (network related) */
char release[_SYS_NAMELEN]; /* Current release level */
char version[_SYS_NAMELEN]; /* Current version level */
char machine[_SYS_NAMELEN]; /* Name of the hardware type */