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sf_time(3)		 BSD Library Functions Manual		    sf_time(3)

NAME
     strtotime,	timetostr -- date and time conversions.

SYNOPSIS
     #include <strfunc.h>

     time_t
     strtotime(char *datestring);

     char *
     timetostr(time_t value, int flags);

DESCRIPTION
     Those functions used to convert time format from string to	binary time_t
     and vice versa.

     strtotime(char *) takes one string	argument that represents the date and
     time in a number of formats, briefly shown	below.	strtotime() is immune
     to	trailing spaces, newlines and other non-printable and printable	tails.
     It	also tries to recognize	elder time formats variants and	strings	cre-
     ated by broken implementations.

     1.	 ISO-8601 notation. This form best suited for use in mixed human/auto-
     matic parsing and comparisons.  The typical date string looks like:

	   20000930T172458+0400
	   or
	   2000-09-30T17:24:58+0400
	   or
	   2000-09-30T21:24:58Z

     2.	 RFC-822 (updated by RFC-1123).	This form used in the E-mail headers,
     like "Data:" and other. The date in this format looks like:

	   Sat,	30 Sep 2000 17:24:58 +0400 (MSD)
	   or
	   Sat,	30 Sep 2000 17:24:58 +0400
	   or even
	   Sat,	30 Sep 2000 17:24:58 MSD
	   that	is but widely used, but	lame,
	   though correctly handled by strtotime.

     3.	 ctime(3) or asctime(3)	form:

	   Sat Sep 30 17:24:58 2000

     4.	 Syslog	daemon's form:

	   Mar 23 19:07:43

     5.	 Unix time in numeric form. This form specifies	the number of seconds
     passed since the Epoch (00:00:00 UTC, January 1, 1970; see	time(3)	).
     Typical form is "970257600" (signed long number).

     Other types.  A set of other formats that are widely used is supported
     too.

	   Thursday, 10-Jun-93 01:29:59	GMT
	   Thu,	10 Jan 1993 01:29:59 GMT
	   Wed Jun  9 01:29:59 1993 GMT
	   1997/06/23 13:22:33

	   and derivatives.

     Support for other time representation formats can be added	upon request.

     timetostr(time_t value, int flags)	used to	convert	the time value to the
     user-specified representation format, specified by	flags. Flags are de-
     fined in strfunc.h:

     TFMT_UNIX - simple	numeric	unix_time format.

     TFMT_CTIME	- ctime(3) and asctime(3) format.

     TFMT_RFC822 - format defined in RFC's 822 and 1123.

     TFMT_X208 - format	specified in X.208.

     TFMT_ISO8601 - general representation according to	ISO-8601 conventions.

     Those flags are present to	specify	the output format. And the following
     ones exist	to slightly modify the output:

     TFMT_LOCAL	- construct string representing	the time within	the local
     timezone instead of default GMT (zero timezone offset).

     TFMT_UF - user-friendly output. This flag turns on	some additional	fea-
     tures like	dashes and colons within the ISO-8601 output or	timezone ab-
     breviation	within the RFC-822 date	string.

     TFMT_OLD822GMT - use old RFC-822 scheme with the hard-coded GMT zone ab-
     breviation. This flag also	disables the TFMT_LOCAL	and TFMT_UF flag will
     be	ignored. The typical string in this format will	look like "Sat,	30 Sep
     2000 21:24:58 GMT".  This time format is widely used by the HTTP browsers
     and CGI scripts to	exchange the "expiration" and "modified" times.	This
     flag should be used in conjunction	with TFMT_RFC822.

     Those flags can be	mixed by OR'ing.

RETURN VALUES
     The strtotime() function returns the value	of given time representation
     in	seconds	since 0	hours, 0 minutes, 0 seconds, January 1,	1970, Coordi-
     nated Universal Time.  If parse error occured, zero is returned and
     global variable errno is set to EINVAL to indicate	an error.

     timetostr() always	returns	pointer	to the internal	static object with
     string representation of given time_t value.

EXAMPLE
     void test() {
	     char *timeString =	"Sat, 1	Oct 2000 01:34:00 +0400";
	     time_t timeValue =	970348600;

	     printf("timeString	-> time_t: %ld\n", (long)strtotime(timeString));

	     printf("timeValue -> string: %s\n",
		     timetostr(timeValue,
			     TFMT_RFC822 | TFMT_LOCAL |	TFMT_UF));
     }

SEE ALSO
     strfunc(3), ctime(3), asctime(3).

AUTHORS
     Lev Walkin	<vlm@lionet.info>

BSD				October	1, 2000				   BSD

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | EXAMPLE | SEE ALSO | AUTHORS

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