您好，如果想让某段代码在10秒或1小时或10小时或......执行，用这个函数能实现吗？

C语言的标准库函数包括一系列日期和时间处理函数，它们都在头文件中说明。在头文件中定义了三种类型：time_t，struct tm和clock_t。下面列出了这些函数。time_t time(time_t *timer);double difftime(time_t time1,time_t time2);struct tm *gmtime(const time_t *timer);struct tm *localtime(const time_t *timer);char *asctime(const struct tm *timeptr);char *ctime(const time_t *timer);size_t strftime(char *s,size_t maxsize,const char *format,const struct tm *timeptr);time_t mktime(struct tm *timeptr);clock_t clock(void);【具体应用举例】asctime（将时间和日期以字符串格式表示）相关函数time，ctime，gmtime，localtime表头文件＃i nclude定义函数char * asctime(const struct tm * timeptr);函数说明asctime()将参数timeptr所指的tm结构中的信息转换成真实世界所使用的时间日期表示方法，然后将结果以字符串形态返回。此函数已经由时区转换成当地时间，字符串格式为:"Wed Jun 30 21:49:08 1993\n"返回值若再调用相关的时间日期函数，此字符串可能会被破坏。此函数与ctime不同处在于传入的参数是不同的结构。附加说明返回一字符串表示目前当地的时间日期。范例＃i ncludemain(){time_t timep;time (&timep);printf("%s",asctime(gmtime(&timep)));}执行Sat Oct 28 02:10:06 2000　ctime（将时间和日期以字符串格式表示）相关函数time，asctime，gmtime，localtime表头文件＃i nclude定义函数char *ctime(const time_t *timep);函数说明ctime ()将参数timep所指的time_t结构中的信息转换成真实世界所使用的时间日期表示方法，然后将结果以字符串形态返回。此函数已经由时区转换成当地时间，字符串格式为"Wed Jun 30 21 :49 :08 1993\n"。若再调用相关的时间日期函数，此字符串可能会被破坏。返回值返回一字符串表示目前当地的时间日期。范例＃i ncludemain(){time_t timep;time (&timep);printf("%s",ctime(&timep));}执行Sat Oct 28 10 : 12 : 05 2000　gettimeofday（取得目前的时间）相关函数time，ctime，ftime，settimeofday表头文件＃i nclude＃i nclude定义函数int gettimeofday ( struct timeval * tv , struct timezone * tz )函数说明gettimeofday()会把目前的时间有tv所指的结构返回，当地时区的信息则放到tz所指的结构中。timeval结构定义为:struct timeval{long tv_sec; /*秒*/long tv_usec; /*微秒*/};timezone 结构定义为:struct timezone{int tz_minuteswest; /*和Greenwich 时间差了多少分钟*/int tz_dsttime; /*日光节约时间的状态*/};上述两个结构都定义在/usr/include/sys/time.h。tz_dsttime 所代表的状态如下DST_NONE /*不使用*/DST_USA /*美国*/DST_AUST /*澳洲*/DST_WET /*西欧*/DST_MET /*中欧*/DST_EET /*东欧*/DST_CAN /*加拿大*/DST_GB /*大不列颠*/DST_RUM /*罗马尼亚*/DST_TUR /*土耳其*/DST_AUSTALT /*澳洲（1986年以后）*/返回值成功则返回0，失败返回－1，错误代码存于errno。附加说明EFAULT指针tv和tz所指的内存空间超出存取权限。范例＃i nclude＃i ncludemain(){struct timeval tv;struct timezone tz;gettimeofday (&tv , &tz);printf("tv_sec; %d\n", tv,.tv_sec) ;printf("tv_usec; %d\n",tv.tv_usec);printf("tz_minuteswest; %d\n", tz.tz_minuteswest);printf("tz_dsttime, %d\n",tz.tz_dsttime);}执行tv_sec: 974857339tv_usec:136996tz_minuteswest:-540tz_dsttime:0　gmtime（取得目前时间和日期）相关函数time,asctime,ctime,localtime表头文件＃i nclude定义函数struct tm*gmtime(const time_t*timep);函数说明gmtime()将参数timep 所指的time_t 结构中的信息转换成真实世界所使用的时间日期表示方法，然后将结果由结构tm返回。结构tm的定义为struct tm{int tm_sec;int tm_min;int tm_hour;int tm_mday;int tm_mon;int tm_year;int tm_wday;int tm_yday;int tm_isdst;};int tm_sec 代表目前秒数，正常范围为0-59，但允许至61秒int tm_min 代表目前分数，范围0-59int tm_hour 从午夜算起的时数，范围为0-23int tm_mday 目前月份的日数，范围01-31int tm_mon 代表目前月份，从一月算起，范围从0-11int tm_year 从1900 年算起至今的年数int tm_wday 一星期的日数，从星期一算起，范围为0-6int tm_yday 从今年1月1日算起至今的天数，范围为0-365int tm_isdst 日光节约时间的旗标此函数返回的时间日期未经时区转换，而是UTC时间。返回值返回结构tm代表目前UTC 时间范例＃i ncludemain(){char *wday[]={"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};time_t timep;struct tm *p;time(&timep);p=gmtime(&timep);printf("%d%d%d",(1900+p->tm_year), (1+p->tm_mon),p->tm_mday);printf("%s%d;%d;%d\n", wday[p->tm_wday], p->tm_hour, p->tm_min, p->tm_sec);}执行2000/10/28 Sat 8:15:38　localtime（取得当地目前时间和日期）相关函数time, asctime, ctime, gmtime表头文件＃i nclude定义函数struct tm *localtime(const time_t * timep);函数说明localtime()将参数timep所指的time_t结构中的信息转换成真实世界所使用的时间日期表示方法，然后将结果由结构tm返回。结构tm的定义请参考gmtime()。此函数返回的时间日期已经转换成当地时区。返回值返回结构tm代表目前的当地时间。范例＃i ncludemain(){char *wday[]={"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};time_t timep;struct tm *p;time(&timep);p=localtime(&timep); /*取得当地时间*/printf ("%d%d%d ", (1900+p->tm_year),( l+p->tm_mon), p->tm_mday);printf("%s%d:%d:%d\n", wday[p->tm_wday],p->tm_hour, p->tm_min, p->tm_sec);}执行2000/10/28 Sat 11:12:22　mktime（将时间结构数据转换成经过的秒数）相关函数time，asctime，gmtime，localtime表头文件＃i nclude定义函数time_t mktime(strcut tm * timeptr);函数说明mktime()用来将参数timeptr所指的tm结构数据转换成从公元1970年1月1日0时0分0 秒算起至今的UTC时间所经过的秒数。返回值返回经过的秒数。范例/* 用time()取得时间（秒数），利用localtime()转换成struct tm 再利用mktine（）将struct tm转换成原来的秒数*/＃i ncludemain(){time_t timep;strcut tm *p;time(&timep);printf("time() : %d \n",timep);p=localtime(&timep);timep = mktime(p);printf("time()->localtime()->mktime():%d\n",timep);}执行time():974943297time()->localtime()->mktime():974943297　settimeofday（设置目前时间）相关函数time，ctime，ftime，gettimeofday表头文件＃i nclude＃i nclude定义函数int settimeofday ( const struct timeval *tv,const struct timezone *tz);函数说明settimeofday()会把目前时间设成由tv所指的结构信息，当地时区信息则设成tz所指的结构。详细的说明请参考gettimeofday()。注意，只有root权限才能使用此函数修改时间。返回值成功则返回0，失败返回－1，错误代码存于errno。错误代码EPERM 并非由root权限调用settimeofday（），权限不够。EINVAL 时区或某个数据是不正确的，无法正确设置时间。　time（取得目前的时间）相关函数ctime，ftime，gettimeofday表头文件＃i nclude定义函数time_t time(time_t *t);函数说明此函数会返回从公元1970年1月1日的UTC时间从0时0分0秒算起到现在所经过的秒数。如果t 并非空指针的话，此函数也会将返回值存到t指针所指的内存。返回值成功则返回秒数，失败则返回((time_t)-1)值，错误原因存于errno中。范例＃i ncludemian(){int seconds= time((time_t*)NULL);printf("%d\n",seconds);}Date and Time Functions: <time.h>The header <time.h> declares types and functions for manipulating date and time. Some functions process local time,which may differ from calendar time, for example because of time zone. clock_t and time_t are arithmetic typesrepresenting times, and struct tm holds the componentsof a calendar time:int tm_sec; seconds after the minute (0,61)int tm_min; minutes after the hour (0,59)int tm_hour; hours since midnight (0,23)int tm_mday; day of the month (1,31)int tm_mon; months since January (0,11)int tm_year; years since 1900int tm_wday; days since Sunday (0,6)int tm_yday; days since January 1 (0,365)int tm_isdst; Daylight Saving Time flagtm_isdst is positive if Daylight Saving Time is in effect, zero if not, and negative if the information is not available.clock_t clock(void)clock returns the processor time used by the program since the beginning of execution, or -1 if unavailable.clock()/CLK_PER_SEC is a time inseconds.time_t time(time_t *tp)time returns the current calendar time or -1 if the time is not available. If tp is not NULL,the return value is also assigned to *tp.double difftime(time_t time2, time_t time1)difftime returns time2-time1 expressed in seconds.time_t mktime(struct tm *tp)mktime converts the local time in the structure *tp into calendar time in the same representation used by time.The components will have valuesin the ranges shown. mktime returns the calendar time or -1 if it cannot be represented.The next four functions return pointers to static objects that may be overwritten by other calls.char *asctime(const struct tm *tp)asctime*tp into a string of the formSun Jan 3 15:14:13 1988\n\0char *ctime(const time_t *tp)ctime converts the calendar time *tp to local time; it is equivalent toasctime(localtime(tp))struct tm *gmtime(const time_t *tp)gmtime converts the calendar time *tp into Coordinated Universal Time (UTC). It returns NULL if UTC is not available.The name gmtime has historical significance.struct tm *localtime(const time_t *tp)localtime converts the calendar time *tp into local time.size_t strftime(char *s, size_t smax, const char *fmt, const struct tm *tp)strftime formats date and time information from *tp into s according to fmt, which is analogous to a printf format.Ordinary characters (including the terminating '\0') are copied into s. Each %c is replaced as described below,using values appropriate for the local environment.No more than smax characters are placed into s. strftime returns the number of characters, excluding the '\0',or zero if more than smax characters were produced.%a abbreviated weekday name.%A full weekday name.%b abbreviated month name.%B full month name.%c local date and time representation.%d day of the month (01-31).%H hour (24-hour clock) (00-23).%I hour (12-hour clock) (01-12).%j day of the year (001-366).%m month (01-12).%M minute (00-59).%p local equivalent of AM or PM.%S second (00-61).%U week number of the year (Sunday as 1st day of week) (00-53).%w weekday (0-6, Sunday is 0).%W week number of the year (Monday as 1st day of week) (00-53).%x local date representation.%X local time representation.%y year without century (00-99).%Y year with century.%Z time zone name, if any.%% %

您好，如果想让某段代码在10秒或1小时或10小时或......执行，用这个函数能实现吗？

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