int sys_popen(const char *command);
int sys_pclose(int fd);
ssize_t sys_getxattr (const char *path, const char *name, void *value, size_t size);
-ssize_t sys_lgetxattr (const char *path, const char *name, void *value, size_t size);
ssize_t sys_fgetxattr (int filedes, const char *name, void *value, size_t size);
ssize_t sys_listxattr (const char *path, char *list, size_t size);
ssize_t sys_llistxattr (const char *path, char *list, size_t size);