datetime.c File Reference

Date and time functions. More...

#include "libtpcmisc.h"
#include <locale.h>
#include <unistd.h>
#include <time.h>

Go to the source code of this file.

Functions
struct tm *	gmtime_r (const time_t *t, struct tm *tm)
	Convert time_t to GMT struct tm.
struct tm *	localtime_r (const time_t *t, struct tm *tm)
	Convert time_t to local time in struct tm.
time_t	timegm (struct tm *tm)
	Inverse of gmtime, converting struct tm to time_t.
char *	ctime_r_int (const time_t *t, char *buf)
	Convert calendard time t into a null-terminated string of the form YYYY-MM-DD hh:mm:ss, with length of 19 characters and the null.
int	isdate (char *str)
int	isdate2 (char *str, char *intdate)
int	isdate3 (char *str, char *intdate)
int	isdate4 (int dateint, int *year, int *month, int *day)
int	istime (char *str)
int	isdatetime (char *str, char *intdate)
int	get_datetime (char *str, struct tm *date, int verbose)
int	get_date (char *str, struct tm *date)
long int	math_div (long int a, long int b)
int	isleapyear (long int year)
long int	leaps_between (long int year1, long int year2)
void	time_to_tm (time_t totalsecs, int offset, struct tm *result)
double	tmDifference (struct tm *tm1, struct tm *tm0)
void	tmAdd (int s, struct tm *d)

Detailed Description

Date and time functions.

Author

Vesa Oikonen

Todo

Use strptime function, when available, to convert string to struct tm.

Definition in file datetime.c.

Function Documentation

ctime_r_int()

char * ctime_r_int	(	const time_t *	t,
		char *	buf )

Convert calendard time t into a null-terminated string of the form YYYY-MM-DD hh:mm:ss, with length of 19 characters and the null.

This is a replacement of the thread-safe ctime_r function which converts to date and time in english format.

Author

Vesa Oikonen

Returns

Returns pointer to the string, or null in case of an error.

Parameters

t	Pointer to calendar time ; do not give pointer to int here, like &e7mhdr.scan_start_time
buf	Pointer to string where the date and time will be written. It must be pre-allocated for at least 20 characters.

Definition at line 110 of file datetime.c.

  {
  if(buf==NULL) return(NULL);
  buf[0]=(char)0;
  struct tm tm;
  if(!gmtime_r(t, &tm)) return(NULL);
  if(!strftime(buf, 20, "%Y-%m-%d %H:%M:%S", &tm)) return(NULL);
  return(buf);
}

Referenced by atnMake(), ecat7MHeaderToIFT(), ecat7PrintMainheader(), fitWrite(), imgGetEcat63MHeader(), imgInfo(), imgSetEcat63MHeader(), imgWriteEcat63Frame(), imgWriteFrame(), plotdata(), resWrite(), resWriteHTML_table(), and sifPrint().

get_date()

int get_date	(	char *	str,
		struct tm *	date )

Reads date from a standard string representation of date.

Returns

Returns 0 when successful, <>0 in case of an error.

Parameters

str	Pointer to string that contains date in one of the formats YYYY-MM-DD, DD/MM/YYYY, DD.MM.YYYY, DD/MM/YY, or DD.MM.YYYY. This string is not modified.
date	Pointer to allocated struct tm where the date is written

Definition at line 377 of file datetime.c.

  {
  char buf[32];
  int ret, n, YYYY=0, MM=0, DD=0;
 
  if(strlen(str)<8) return 1;
  if((ret=isdate(str))<=0) {
    strncpy(buf, str, 10); buf[10]=(char)0; 
  } else {
    ret=isdate2(str, buf);
    if(ret>0) ret=isdate3(str, buf);
  }
  if(ret>0) return 2;
  n=sscanf(buf, "%d-%d-%d", &YYYY, &MM, &DD);
  if(n!=3) return(3);
  date->tm_year=YYYY-1900; date->tm_mday=DD; date->tm_mon=MM-1;
  date->tm_hour=0; date->tm_min=0; date->tm_sec=0;  date->tm_isdst=-1;
  ret=strftime(buf, 32, "%Y-%m-%d %H:%M:%S", date);
  if(ret==0) return(4);
  return(0);
}

Referenced by resRead().

get_datetime()

int get_datetime	(	char *	str,
		struct tm *	date,
		int	verbose )

Reads time and date from a standard string representation of date and time.

Returns

Returns 0 when successful, <>0 in case of an error.

Parameters

str	Pointer to string that contains date and time in one of the formats YYYY-MM-DD hh:mm:ss, DD.MM.YYYY hh:mm:ss, or DD/MM/YY hh:mm:ss This string is not modified.
date	Pointer to allocated struct tm where date and time is written
verbose	Verbose level; if <=0, then nothing is printed into stdout

Definition at line 322 of file datetime.c.

  {
  char buf[32];
  int ret, n, YYYY=0, MM=0, DD=0, hh=0, mm=0, ss=0;
 
  if(verbose>0) printf("get_datetime(%s)\n", str);
  if(date==NULL) return(1);
  ret=isdatetime(str, buf); if(ret!=0) return(ret);
  n=sscanf(buf, "%d-%d-%d %d:%d:%d", &YYYY, &MM, &DD, &hh, &mm, &ss);
  if(n!=6) return(40);
  date->tm_year=YYYY-1900; date->tm_mday=DD; date->tm_mon=MM-1;
  date->tm_hour=hh; date->tm_min=mm; date->tm_sec=ss; 
  date->tm_isdst=-1;
#ifdef HAVE_TM_GMTOFF
  date->tm_gmtoff=0L;
#endif
  if(verbose>2) {
    printf("tm_mday=%d\n", date->tm_mday);
    printf("tm_mon=%d\n", date->tm_mon);
    printf("tm_year=%d\n", date->tm_year);
    printf("tm_hour=%d\n", date->tm_hour);
    time_t t=timegm(date);
    printf(" tm_hour=%d\n", date->tm_hour);
    printf("time_t=%ld\n", (long)t);
    printf("time_t_int=%d\n", (int)t);
  }
//  if(mktime(date)==-1 && date->tm_year<70) {
  if(timegm(date)==-1 && date->tm_year<70) {
    if(verbose>2) printf("tm_mday=%d\n", date->tm_mday);
    if(verbose>1) printf("mktime() fails\n");
    /* Date and time format was previously verified, so lets put
       1970-01-01 01:00:00 instead */  
    date->tm_year=70; date->tm_mday=1; date->tm_mon=0;
    date->tm_hour=1; date->tm_min=0; date->tm_sec=0; 
    date->tm_yday=0;
    date->tm_isdst=-1;
    mktime(date);
  }
  if(verbose>1) printf(" tm_hour=%d\n", date->tm_hour);
  return(0);
}

Referenced by ecat7EditMHeader(), fitRead(), resRead(), and selectEcat931Calibrationfile().

gmtime_r()

struct tm * gmtime_r	(	const time_t *	t,
		struct tm *	tm )

Convert time_t to GMT struct tm.

This version of gmtime_r function is here for systems (at least Windows) where it is not defined. Uses gmtime, which is threadsafe in Windows.

Returns

Pointer to struct tm, or null in case of an error.

Parameters

t	Pointer to time_t; do not give pointer to int here, like &e7mhdr.scan_start_time
tm	Pointer to struct tm, to be filled here

Definition at line 22 of file datetime.c.

  {
  struct tm *ltm=gmtime(t);
  if(ltm==NULL || tm==NULL) return(NULL);
  *tm=*ltm; tm->tm_isdst=-1;
  return tm;
}

Referenced by ctime_r_int(), ecat63AddImg(), ecat63WriteAllImg(), ecat7EditMHeader(), ecat7ReadMainheader(), ecatCopy7to63mainheader(), imgSetAnalyzeHeader(), imgSetEcat63MHeader(), imgWriteAnalyze(), res2ift(), sifWrite(), time_to_tm(), and timegm().

isdate()

int isdate

(

char *

str

)

Check if specified string contains date in correct international format (YYYY-MM-DD). String must start with date, but any contents after it is ignored.

Returns

Returns 0 if date is in correct format, -1 if format is correct but date is invalid, and otherwise <>0.

Parameters

str	String to be checked; not changed in this routine

Definition at line 146 of file datetime.c.

  {
  int Y, M, D, n;
  if(strlen(str)<10) return 1;
  if(str[4]!='-' || str[7]!='-') return 2;
  if(strncasecmp(str, "YYYY-MM-DD", 10)==0) return -1;
  n=sscanf(str, "%4d-%2d-%2d", &Y, &M, &D); if(n!=3) return 3;
  if(M>12 || D>31) return -1;
  if(Y<0 || M<1 || D<1) return -1;
  return 0;
}

Referenced by dcmDA2intl(), get_date(), and isdatetime().

isdate2()

int isdate2	(	char *	str,
		char *	intdate )

Check if specified string contains date in correct format (DD.MM.YYYY or DD/MM/YYYY). String must start with date, but any contents after it is ignored.

Returns

Returns 0 if date is in correct format, -1 if format is correct but date is invalid, and otherwise <>0.

Parameters

str	String to be checked; not changed in this routine
intdate	Pointer to allocated string where date is written in international format; enter NULL, if not needed.

Definition at line 168 of file datetime.c.

  {
  int Y, M, D, n;
  if(strlen(str)<10) return 1;
  if(str[2]!='.' && str[2]!='/') return 2;
  if(str[5]!='.' && str[5]!='/') return 2;
  if(isspace(str[8])) return 2;
  if(strncasecmp(str, "DD.MM.YYYY", 10)==0 ||
     strncasecmp(str, "DD/MM/YYYY", 10)==0) return -1;
  n=sscanf(str, "%2d/%2d/%4d", &D, &M, &Y);
  if(n<3) n=sscanf(str, "%2d.%2d.%4d", &D, &M, &Y);
  if(n!=3) return 3;
  if(M>12 || D>31) return -1;
  if(Y<0 || M<1 || D<1) return -1;
  if(intdate!=NULL) sprintf(intdate, "%04d-%02d-%02d", Y, M, D);
  return 0;
}

Referenced by get_date(), and isdatetime().

isdate3()

int isdate3	(	char *	str,
		char *	intdate )

Check if specified string contains date in correct format (DD.MM.YY or DD/MM/YY). String must start with date, but any contents after it is ignored.

Returns

Returns 0 if date is in correct format, -1 if format is correct but date is invalid, and otherwise <>0.

Parameters

str	String to be checked; not changed in this routine
intdate	Pointer to allocated string where date is written in international format; enter NULL, if not needed.

Definition at line 199 of file datetime.c.

  {
  int Y, M, D, n;
  if(strlen(str)<8) return 1;
  if(str[2]!='.' && str[2]!='/') return 2;
  if(str[5]!='.' && str[5]!='/') return 2;
  if(strncasecmp(str, "DD.MM.YY", 8)==0 ||
     strncasecmp(str, "DD/MM/YY", 8)==0) return -1;
  n=sscanf(str, "%2d/%2d/%2d", &D, &M, &Y);
  if(n<3) n=sscanf(str, "%2d.%2d.%2d", &D, &M, &Y);
  if(n!=3) return 3;
  if(Y>99 || M>12 || D>31) return -1;
  if(Y<0 || M<1 || D<1) return -1;
  if(intdate!=NULL) {
    if(Y>=70) Y+=1900; else Y+=2000;
    sprintf(intdate, "%04d-%02d-%02d", Y, M, D);
  }
  return 0;
}

Referenced by get_date(), and isdatetime().

isdate4()

int isdate4	(	int	dateint,
		int *	year,
		int *	month,
		int *	day )

Check if specified integer contains date in format YYYYMMDD.

Returns

Returns 0 if date is in correct format, -1 if format is correct but date is invalid, and otherwise <>0.

Parameters

dateint	Integer to be checked; not changed in this routine
year	Year is written in this pointer; enter NULL if not needed
month	Month is written in this pointer; enter NULL if not needed
day	Day is written in this pointer; enter NULL if not needed

Definition at line 230 of file datetime.c.

  {
  int Y, M, D, n;
  if(dateint<1201 || dateint>99991231) return 1;
  n=dateint/100; D=dateint-100*n; Y=n/100; M=n-100*Y;
  if(M>12 || D>31) return -1;
  if(Y<1 || M<1 || D<1) return -1;
  if(year!=NULL) *year=Y;
  if(month!=NULL) *month=M;
  if(day!=NULL) *day=D;
  return 0;
}

Referenced by ecat7ReadMainheader().

isdatetime()

int isdatetime	(	char *	str,
		char *	intdate )

Check if specified string contains date and time in correct format (YYYY-MM-DD hh:mm:ss, DD.MM.YYYY hh:mm:ss, or DD.MM.YY hh:mm:ss). String must start with date, but any contents after time is ignored.

Returns

Returns 0 if date and time are in correct format, <0 if format is correct but date or time is invalid, and otherwise <>0.

Parameters

str	String to be checked; not changed in this routine
intdate	Pointer to allocated string where date and time is written in international format (YYYY-MM-DD hh:mm:ss); enter NULL, if not needed.

Definition at line 280 of file datetime.c.

  {
  int ret1, ret2, len, type=0;
  char correct_date[20], *time_ptr=NULL;
 
  len=strlen(str); if(len<17) return 1;
  if((ret1=isdate(str))<=0) {
    type=1; strncpy(correct_date, str, 10); correct_date[10]=(char)0; 
  } else if((ret1=isdate2(str, correct_date))<=0) type=2;
  else if((ret1=isdate3(str, correct_date))<=0) type=3;
  else {return 2;}
  if(type==1 || type==2) {
    if(str[10]!=' ' && str[10]!='\t') return 3;
    time_ptr=str+11;
  } else if(type==3) {
    if(str[8]!=' ' && str[8]!='\t') return 3;
    time_ptr=str+9;
  }
  ret2=istime(time_ptr);
  if(ret1>0) {
    if(ret2>=0) return(100*ret1+ret2); else return(100*ret2);
  }
  if(ret2>0) return(10*ret2);
  if(ret1<0) {if(ret2<0) return(-3); else return(-1);}
  if(ret2<0) return(-2);
  if(intdate!=NULL) {
    sprintf(intdate, "%10.10s %8.8s", correct_date, time_ptr);
  }
  return 0;
}

Referenced by dcmDT2intl(), and get_datetime().

isleapyear()

int isleapyear

(

long int

year

)

Check for leap year.

Returns

Nonzero if 'year' is a leap year.

Parameters

year

Year

Definition at line 423 of file datetime.c.

  {
  return (year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0);
}

Referenced by time_to_tm().

istime()

int istime

(

char *

str

)

Check if specified string contains time in correct format (hh:mm:ss). String must start with time, but any contents after it is ignored.

Returns

Returns 0 if time is in correct format, -1 if format is correct but time is invalid, and otherwise <>0.

Parameters

str	String to be checked; not changed in this routine

Definition at line 259 of file datetime.c.

  {
  int h, m, s, n;
  if(strlen(str)<8) return 1;
  if(str[2]!=':' || str[5]!=':') return 2;
  if(strncasecmp(str, "hh:mm:ss", 8)==0) return -1;
  n=sscanf(str, "%d:%d:%d", &h, &m, &s); if(n!=3) return 3;
  if(h<0 || h>23 || m<0 || m>59 || s<0 || s>59) return -1;
  return 0;
}

Referenced by dcmTM2intl(), iftRead(), and isdatetime().

leaps_between()

long int leaps_between	(	long int	year1,
		long int	year2 )

Calculates the number of leap years between year1 and year2.

Returns

Nr of leap years.

Parameters

year1	Year 1
year2	Year 2

Definition at line 435 of file datetime.c.

  {
  long int leaps1, leaps2;
 
  leaps1 = math_div(year1-1, 4) - math_div(year1-1, 100) + math_div(year1-1, 400);
  leaps2 = math_div(year2-1, 4) - math_div(year2-1, 100) + math_div(year2-1, 400);
  return(leaps2-leaps1);
}

Referenced by time_to_tm().

localtime_r()

struct tm * localtime_r	(	const time_t *	t,
		struct tm *	tm )

Convert time_t to local time in struct tm.

This version of localtime_r function is here for systems (at least Windows) where it is not defined. Uses localtime, which is threadsafe in Windows.

See also

gmtime_r

Returns

Pointer to struct tm, or null in case of an error.

Parameters

t	Pointer to time_t; do not give pointer to int here, like &e7mhdr.scan_start_time
tm	Pointer to struct tm, to be filled here

Definition at line 46 of file datetime.c.

  {
  struct tm *ltm=localtime(t);
  if(ltm==NULL || tm==NULL) return(NULL);
  *tm=*ltm; tm->tm_isdst=-1;
  return tm;
}

math_div()

long int math_div	(	long int	a,
		long int	b )

Division for long integers.

Returns

a/b

Parameters

a	A/b
b	a/B

Definition at line 409 of file datetime.c.

  {
  return a/b - (a%b < 0);
}

Referenced by leaps_between(), and time_to_tm().

time_to_tm()

void time_to_tm	(	time_t	totalsecs,
		int	offset,
		struct tm *	result )

Convert calendar time to local broken-down time. This function is copied from GNU C Library with tiny modifications.

Parameters

totalsecs	number of seconds elapsed since 00:00:00 on January 1, 1970, UTC; can be negative to represent times before 1970
offset	offset seconds adding to totalsecs (e.g. -timezone)
result	pointer to struct tm variable to receive broken-down time

Definition at line 452 of file datetime.c.

  {
  if(offset==0) {gmtime_r(&totalsecs, result); return;}
 
 
  long int days, rem, y, yg;
  const unsigned short *ip;
 
  days=totalsecs/86400; rem=totalsecs%86400; rem+=offset;
  while(rem<0) {rem+=86400; --days;}
  while(rem>=86400) {rem-=86400; ++days;}
  result->tm_hour=rem/3600;
  rem%=3600; result->tm_min=rem/60;
  result->tm_sec=rem%60;
 
  /* January 1, 1970 was a Thursday. */
  result->tm_wday=(4+days)%7;
  if(result->tm_wday<0) result->tm_wday+=7;
  y=1970;
  while(days<0 || days>=(isleapyear(y)?366:365)) {
    /* Guess a corrected year, assuming 365 days per year. */
    yg=y+math_div(days, 365);
    /* Adjust days and y to match the guessed year. */
    days-=(yg-y)*365 + leaps_between(y, yg);
    y=yg;
  }
  result->tm_year=y-1900; result->tm_yday=days;
  ip=__mon_yday[isleapyear(y)];
  for(y=11; days<ip[y]; y--) continue;
  days-=ip[y];
  result->tm_mon=y;
  result->tm_mday=days+1;
  result->tm_isdst=-1;
#if defined(HAVE_TM_GMTOFF)
  result->tm_gmtoff=0L;
#endif
}

timegm()

time_t timegm

(

struct tm *

tm

)

Inverse of gmtime, converting struct tm to time_t.

Otherwise same as mktime, except that mktime uses local time. Uses gmtime_r or gmtime_s, if available, otherwise gmtime, which is threadsafe in Windows.

Returns

Returns the time_t, or -1 in case of an error.

Parameters

tm	Pointer to struct tm

Definition at line 69 of file datetime.c.

  {
#ifdef HAVE_GMTIME_R
  {
  time_t temp_lt;
  struct tm temp_gm;
  if(!tm) temp_lt=0; else temp_lt=mktime(tm);
  if(gmtime_r(&temp_lt, &temp_gm)==NULL) return((time_t)-1);
  return(time_t)(temp_lt + (temp_lt - mktime(&temp_gm)));
  }
#endif
 
#ifdef HAVE_GMTIME_S
  {
  time_t temp_lt;
  struct tm temp_gm;
  if(!tm) temp_lt=0; else temp_lt=mktime(tm);
  if(gmtime_s(&temp_gm, &temp_lt)!=0) return(time_t)-1);
  return(time_t)(temp_lt + (temp_lt - mktime(&temp_gm)));
  }
#endif
 
  time_t temp_lt;
  struct tm *temp_gm;
  if(!tm) temp_lt=0; else {tm->tm_isdst=-1; temp_lt=mktime(tm);}
  temp_gm=gmtime(&temp_lt); if(temp_gm) temp_gm->tm_isdst=-1;
  return(time_t)(temp_lt + (temp_lt - mktime(temp_gm)));
}

Referenced by ecat63Scanstarttime(), ecat63ScanstarttimeToTm(), ecat7EditMHeader(), fitRead(), get_datetime(), imgGetMicropetHeader(), resRead(), sifRead(), tmAdd(), and upetScanStart().

tmAdd()

void tmAdd	(	int	s,
		struct tm *	d )

Add given time in seconds to the date and time.

Parameters

s	Time to add in seconds; can be negative
d	Pointer to tm struct

Definition at line 514 of file datetime.c.

  {
  if(d==NULL) return;
  d->tm_sec+=s; 
  //mktime(d); // this automatically normalizes sec to hours etc if necessary
  timegm(d); // this automatically normalizes sec to hours etc if necessary
}

tmDifference()

double tmDifference	(	struct tm *	tm1,
		struct tm *	tm0 )

Calculate the difference in seconds between two given dates and times.

Returns

Returns tm1-tm0 in seconds.

Parameters

tm1	Pointer to tm struct
tm0	Pointer to tm struct

Definition at line 502 of file datetime.c.

  {
  return(difftime(mktime(tm1), mktime(tm0)));
}

Referenced by selectEcat931Calibrationfile().