TIME
Since:
1.0
Version:
1.0
Summary
Files
Data Structures
Macros
Functions
ftime (struct tp) |
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difftime (time_t time1, time_t time2) |
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(struct tm ) |
Converts the broken-down time in the tm structure into seconds. |
(char restrict s, size_t n, const char restrict f, const struct tm restrict ) |
Converts the broken-down time in the tm structure to a string in the required format. |
struct tm Converts the number of seconds to the UTC time in the structure. |
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localtime (const time_t t) |
Converts the number of seconds to the local time in the tm structure. |
(const struct tm ) |
Converts the broken-down time in the tm structure into a string. |
strftime_l (char restrict s, size_t n, const char *restrict f, const struct __restrict tm, locale_t loc) |
Converts the broken-down time in the structure to a string in a specified programming language and format. |
Converts the number of seconds to the UTC time in the tm structure. (This function is reentrant.) |
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(const time_t restrict t, struct tm *restrict ) |
struct tm Converts the number of seconds to the local time in the structure. (This function is reentrant.) |
Converts the broken-down time in the structure into a string. (This function is reentrant.) |
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ctime_r (const time_t t, char buf) |
Converts the date and time into a string. (This function is reentrant.) |
(const struct timespec tspec1, struct tspec2) |
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clock_getres (clockid_t id, struct tspec) |
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clock_gettime (clockid_t id, struct tspec) |
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clock_settime (clockid_t id, const struct tspec) |
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clock_nanosleep (clockid_t id, int flag, const struct tspec1, struct timespec tspec2) |
Pauses the current thread until a specified time of a clock arrives. |
(clockid_t id, struct sigevent restrict evp, timer_t *restrict t) |
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timer_settime (timer_t t, int flags, const struct __restrict val, struct itimerspec __restrict old) |
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(timer_t t, struct itimerspec tspec) |
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Converts a time string to the broken-down time in the structure. |
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getdate (const char buf) |
Converts a time string to the broken-down time in the tm structure. |
Converts the broken-down time in the structure to the number of seconds. |
Details
Macro Definition Documentation
CLOCK_REALTIME
Description:
Defines the clock that runs in real time.
Function Documentation
asctime()
Description:
Converts the broken-down time in the structure into a string.
Parameters:
tm | Indicates the pointer to the broken-down time in the structure. |
Returns:
Returns the string in the format of week month day hour:minute:second year, for example, Thu Jan 1 08:00:00 1970. If the conversion fails, the program ends.
asctime_r()
char* asctime_r (const struct [tm]($api-api-SmartVision-Devices-tm.md) *__restrict tm, char *__restrict buf )
Description:
Converts the broken-down time in the structure into a string. (This function is reentrant.)
Parameters:
tm | Indicates the pointer to the broken-down time in the structure. |
buf | Indicates the pointer to the buffer for storing the string. |
Returns:
Returns the string in the format of week month day hour:minute:second year, for example, Thu Jan 1 08:00:00 1970. If the conversion fails, the program ends.
clock_getres()
int clock_getres (clockid_t id, struct [timespec]($api-api-SmartVision-Devices-timespec.md) * tspec )
Description:
Obtains the precision of a clock.
Parameters:
Returns:
Returns 0 if the operation is successful; returns -1 otherwise.
int clock_gettime (clockid_t id, struct [timespec]($api-api-SmartVision-Devices-timespec.md) * tspec )
Description:
Obtains the time of a clock.
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
clock_nanosleep()
Description:
Pauses the current thread until a specified time of a clock arrives.
A sleeping thread cannot be woken up by a signal.
Parameters:
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
clock_settime()
int clock_settime (clockid_t id, const struct [timespec]($api-api-SmartVision-Devices-timespec.md) * tspec )
Description:
Sets the time for a clock.
Parameters:
id | Indicates the clock ID. Only CLOCK_REALTIME is supported. |
tspec | Indicates the pointer to the time to set. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
ctime()
char* ctime (const time_t * timep)
Description:
Converts the date and time into a string.
Parameters:
timep | Indicates the number of seconds to convert. |
Returns:
Returns the string in the format of week month day hour:minute:second year, for example, Thu Jan 1 08:00:00 1970. If the conversion fails, the program ends.
ctime_r()
char* ctime_r (const time_t * t, char * buf )
Description:
Converts the date and time into a string. (This function is reentrant.)
Parameters:
t | Indicates the pointer to the number of seconds to convert. |
buf | Indicates the pointer to the buffer for storing the string. |
Returns:
Returns the string in the format of week month day hour:minute:second year, for example, Thu Jan 1 08:00:00 1970. If the conversion fails, the program ends.
difftime()
double difftime (time_t time1, time_t time2 )
Description:
Calculates the difference between two times, in seconds.
Parameters:
time1 | Indicates the first time. |
time2 | Indicates the second time. |
Returns:
Returns the difference, represented using a double.
ftime()
Description:
Obtains the current time, accurate to milliseconds.
The time obtained is the total number of milliseconds elapsed since January 1, 1970 00:00:00 (UTC).
Parameters:
Returns:
Returns 0 if the operation is successful; returns -1 otherwise.
getdate()
Description:
Converts a time string to the broken-down time in the structure.
Parameters:
buf | Indicates the pointer to the time string. The format is specified by the file defined by the environment variable DATEMSK. |
Returns:
Returns the time in the structure if the operation is successful; returns NULL otherwise.
gmtime()
struct [tm]($api-api-SmartVision-Devices-tm.md)* gmtime (const time_t * t)
Description:
Converts the number of seconds to the UTC time in the structure.
Parameters:
t | Indicates the pointer to the number of seconds to convert. |
Returns:
Returns the pointer to the UTC time in the structure if the conversion is successful; returns NULL and sets errno to a value in the following table if the operation fails.
gmtime_r()
struct [tm]($api-api-SmartVision-Devices-tm.md)* gmtime_r (const time_t *__restrict t, struct [tm]($api-api-SmartVision-Devices-tm.md) *__restrict tm )
Description:
Converts the number of seconds to the UTC time in the tm structure. (This function is reentrant.)
This function is used in the multi-task environment.
Parameters:
t | Indicates the pointer to the number of seconds to convert. |
tm | Indicates the pointer to the tm structure. |
Returns:
Returns the pointer to the UTC time in the structure if the conversion is successful; returns NULL and sets errno to a value in the following table if the operation fails.
localtime()
struct [tm]($api-api-SmartVision-Devices-tm.md)* localtime (const time_t * t)
Description:
Converts the number of seconds to the local time in the tm structure.
Parameters:
t | Indicates the pointer to the number of seconds to convert. |
Returns:
Returns the pointer to the local time in the tm structure if the conversion is successful; returns NULL and sets errno to a value in the following table if the operation fails.
localtime_r()
struct [tm]($api-api-SmartVision-Devices-tm.md)* localtime_r (const time_t *__restrict t, struct [tm]($api-api-SmartVision-Devices-tm.md) *__restrict tm )
Description:
Converts the number of seconds to the local time in the structure. (This function is reentrant.)
Parameters:
t | Indicates the pointer to the number of seconds to convert. |
tm | Indicates the pointer to the structure. |
Returns:
Returns the pointer to the local time in the tm structure if the conversion is successful; returns NULL and sets errno to a value in the following table if the operation fails.
mktime()
time_t mktime (struct [tm]($api-api-SmartVision-Devices-tm.md) * tm)
Description:
Converts the broken-down time in the structure into seconds.
Parameters:
tm | Indicates the pointer to the broken-down time in the structure. |
Returns:
Returns the total number of seconds elapsed since January 1, 1970 00:00:00 (UTC) if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
int nanosleep (const struct [timespec]($api-api-SmartVision-Devices-timespec.md) * tspec1, struct [timespec]($api-api-SmartVision-Devices-timespec.md) * tspec2 )
Description:
Pauses the current thread until a specified time arrives.
A sleeping thread cannot be woken up by a signal.
tspec1 | Indicates the pointer to the minimum duration that the current thread is paused. Currently, the unit of precision is tick, and the discrepancy is fewer than 2 ticks. |
tspec2 | This parameter is not used yet. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
stime()
int stime (const time_t * t)
Description:
Sets the system time.
Parameters:
t | Indicates the pointer to the number of seconds to set. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
strftime()
size_t strftime (char *restrict s, size_t n, const char *restrict f, const struct [tm]($api-api-SmartVision-Devices-tm.md) *restrict tm )
Description:
Converts the broken-down time in the structure to a string in the required format.
Parameters:
Returns:
Returns the number of bytes in the string if the conversion is successful; returns 0 otherwise.
strftime_l()
Description:
Converts the broken-down time in the tm structure to a string in a specified programming language and format.
Parameters:
s | Indicates the pointer to the string. |
n | Indicates the size of the buffer for storing the string. |
f | Indicates the pointer to the required format. |
tm | Indicates the pointer to the broken-down time in the tm structure. |
loc | Indicates the required programming language. Currently, only C programming language is supported. |
Returns:
Returns the number of bytes in the string if the conversion is successful; returns 0 otherwise.
strptime()
Description:
Converts a time string to the broken-down time in the tm structure.
This function parses the input string s based on format and stores the result in the structure.
Parameters:
s | Indicates the pointer to the string that contains only time data. |
format | Indicates the pointer to the required format. |
tm | Indicates the pointer to the structure. |
Returns:
Returns the pointer to the position to which the string has been processed (the next character to be processed) upon the conversion completion if the operation is successful; returns NULL otherwise.
time()
time_t time (time_t * t)
Description:
Obtains the time.
The time obtained is the total number of seconds elapsed since January 1, 1970 00:00:00 (UTC).
Parameters:
t | Indicates the pointer to the number of seconds. You can also pass NULL to use the return value. |
Returns:
Returns the number of seconds.
timegm()
time_t timegm (struct [tm]($api-api-SmartVision-Devices-tm.md) * tm)
Description:
Converts the broken-down time in the structure to the number of seconds.
Parameters:
tm | Indicates the pointer to the broken-down time in the structure to convert. |
Returns:
Returns the number of seconds if the operation is successful; returns NULL and sets errno to a value in the following table if the operation fails.
timer_create()
int timer_create (clockid_t id, struct [sigevent]($api-api-SmartVision-Devices-sigevent.md) *__restrict evp, timer_t *__restrict t )
Description:
Creates a timer for the process.
Parameters:
id | Indicates the clock ID. Only CLOCK_REALTIME is supported. |
evp | Indicates the pointer to the asynchronous notification signal and action, which can be NULL. |
t | Indicates the pointer to the timer ID. |
Attention:
sigev_notify in the sigevent structure must be SIGEV_SIGNAL.
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
The value of evp is not NULL and sigev_notify is not SIGEV_SIGNAL. |
timer_delete()
int timer_delete (timer_t t)
Description:
Deletes a timer for the process.
Parameters:
t | Indicates the ID of the timer to delete. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
timer_getoverrun()
int timer_getoverrun (timer_t t)
Description:
Obtains the number of times that a timer overruns.
Parameters:
t | Indicates the ID of the timer to obtain. |
Returns:
Returns the number of times if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
timer_gettime()
int timer_gettime (timer_t t, struct [itimerspec]($api-api-SmartVision-Devices-itimerspec.md) * tspec )
Description:
Obtains a timer of the process.
Parameters:
t | Indicates the ID of the timer to obtain. |
tspec | Indicates the pointer to the timer duration and interval. |
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
timer_settime()
int timer_settime (timer_t t, int flags, const struct [itimerspec]($api-api-SmartVision-Devices-itimerspec.md) *__restrict val, struct [itimerspec]($api-api-SmartVision-Devices-itimerspec.md) *__restrict old )
Description:
Sets a timer for the process.
Parameters:
Returns:
Returns 0 if the operation is successful; returns -1 and sets errno to a value in the following table if the operation fails.
times()
Description:
Obtains the number of clock ticks of the current process.
Parameters:
Returns the number of clock ticks of CPU 0.