MAX_SYSFS_ATTR_NAME_LENGTH
char name[MAX_SYSFS_ATTR_NAME_LENGTH];
char event[MAX_SYSFS_ATTR_NAME_LENGTH + 5];
char sattr[MAX_SYSFS_ATTR_NAME_LENGTH];
scnprintf(sattr, MAX_SYSFS_ATTR_NAME_LENGTH, template, base + channel);