HP C/iX Library Reference Manual (30026-90004)

52 Chapter4
HP C/iX Library Header Descriptions
Header File Contents
CLOCKS_PER_SEC macro The number of clock ticks per second, as counted by the
clock function.
ctime() function Converts a calendar time into a 26-character ASCII string.
daylight
a
global variable Communicates with functions in this library. See the
function descriptions in chapter 5 for more information.
difftime() function Computes the difference between two times.
gmtime() function Converts time to Coordinated Universal Time (UTC) in the
structured tm type format.
localtime() function Converts time to the local time zone.
mktime() function Converts a broken-down time of type struct tm to a
calendar time of of type time_t.
NULL macro The constant 0.
size_t type definition The data type used to return values from the sizeof
operator.
strftime() function Creates a formatted time string.
time() function Returns the current calendar time.
time_t type definition A data type definition used to return values from the time
function. It is also used to declare return values and
parameters of other time.h> functions. A time value
represented using type time_t is referred to as a calendar
time.
timezone macro A constant containing the offset of the local time zone to
GMT. The local time zone defaults to EST. This value can be
changed by setting the environment variable TZ using the
SETVAR command.
tm type definition A structure data type definition used to declare parameters
and return values for time.h> functions. Contains the
components of a calendar time value, broken down into
individual fields for year, month, day, hour, and so on. A
time value represented using type struct tm is referred to
as a broken-down time.
tzname
b
global variable An external variable used to communicate with functions in
this library. See the time function descriptions in chapter 5
for more information.
tzset() function Sets time zone conversion information.
a. These identifiers are not defined by the ANSI C standard. Programs using these
identifiers are likely to be less portable.
Table 4-16. Date and Time <time.h>
Name Type Description