NAME

SYNOPSIS

time_t
strtotime(char *datestring);

char *
timetostr(time_t value, int flags);

DESCRIPTION

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 created by broken implementations.

1. ISO-8601 notation. This form best suited for use in mixed human/automatic 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 defined 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 features like dashes and colons within the ISO-8601 output or timezone abbreviation within the RFC-822 date string.

TFMT_OLD822GMT - use old RFC-822 scheme with the hard-coded GMT zone abbreviation. 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

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

AUTHORS