strptime - convert a string representation of time to a time tm structure
#define _XOPEN_SOURCE /* glibc2 needs this */
#include <time.h>
char *strptime(const char *s, const char *format, struct tm *tm);
strptime() is the complementary function to strftime() and converts the
character string pointed to by s to values which are stored in the tm
structure pointed to by tm, using the format specified by format. Here
format is a character string that consists of field descriptors and
text characters, reminiscent of scanf(3). Each field descriptor consists
of a % character followed by another character that specifies the
replacement for the field descriptor. All other characters in the for-
mat string must have a matching character in the input string. Exceptions
are white spaces in the format string which can match zero or
more white space characters in the input string.
The strptime() function processes the input string from right to left.
Each of the three possible input elements (white space, literal, or
format) are handled one after the other. If the input cannot be
matched to the format string the function stops. The remainder of the
format and input strings are not processed.
The following field descriptors are supported:
%% the % character
%a or %A
day of week, using locale's weekday names; either the abbreviated
or full name may be specified
%b or %B or %h
month, using locale's month names; either the abbreviated or
full name may be specified
%c date and time as %x %X
%C date and time, in locale's long-format date and time representation
%d or %e
day of month (1-31; leading zeroes are permitted but not
required)
%D date as %m/%d/%y
%H or %k
hour (0-23; leading zeroes are permitted but not required)
%I or %l
hour (0-12; leading zeroes are permitted but not required)
%j day number of year (001-366)
%m month number (1-12; leading zeroes are permitted but not
required)
%M minute (0-59; leading zeroes are permitted but not required)
%p locale's equivalent of AM or PM
%r time as %I:%M:%S %p
%R time as %H:%M
%S seconds (0-61; leading zeroes are permitted but not required.
Extra second allowed for leap years)
%T time as %H:%M:%S
%w weekday number (0-6) with Sunday as the first day of the week
%x date, using locale's date format
%X time, using locale's time format
%y year within century (0-99; leading zeroes are permitted but not
required. When a century is not otherwise specified, values in
the range 69-99 refer to years in the twentieth century (1969 to
1999 inclusive); values in the range 00-68 refer to years in the
twenty-first century (2000 to 2068 inclusive).
%Y year, including century (for example, 1988)
Case is ignored when matching items such as month or weekday names.
Some field descriptors can be modified by the E and O modifier characters
to indicate that an alternative format or specification should be
used. If the alternative format or specification does not exist in the
current locale, the unmodified field descriptors is used.
The E modifier specifies that the input string may contain alternative
locale-dependent versions of the date and time representation:
%Ec the locale's alternative date and time representation.
%EC the name of the base year (period) in the locale's alternative
representation.
%Ex the locale's alternative date representation.
%EX the locale's alternative time representation.
%Ey the offset from %EC (year only) in the locale's alternative representation.
%EY the full alternative year representation.
The O modifier specifies that the numerical input may be in an alternative
locale-dependent format:
%Od or %Oe
the day of the month using the locale's alternative numeric symbols;
leading zeros are permitted but not required.
%OH the hour (24-hour clock) using the locale's alternative numeric
symbols.
%OI the hour (12-hour clock) using the locale's alternative numeric
symbols.
%Om the month using the locale's alternative numeric symbols.
%OM the minutes using the locale's alternative numeric symbols.
%OS the seconds using the locale's alternative numeric symbols.
%OU the week number of the year (Sunday as the first day of the
week) using the locale's alternative numeric symbols.
%Ow the number of the weekday (Sunday=0) using the locale's alternative
numeric symbols.
%OW the week number of the year (Monday as the first day of the
week) using the locale's alternative numeric symbols.
%Oy the year (offset from %C) using the locale's alternative numeric
symbols.
The broken-down time structure tm is defined in <time.h> as follows:
struct tm
{
int tm_sec; /* seconds */
int tm_min; /* minutes */
int tm_hour; /* hours */
int tm_mday; /* day of the month */
int tm_mon; /* month */
int tm_year; /* year */
int tm_wday; /* day of the week */
int tm_yday; /* day in the year */
int tm_isdst; /* daylight saving time */
};
The return value of the function is a pointer to the first character
not processed in this function call. In case the input string contains
more characters than required by the format string the return value
points right after the last consumed input character. In case the
whole input string is consumed the return value points to the NUL byte
at the end of the string. If strptime() fails to match all of the format
string and therefore an error occurred the function returns NULL.
In principle, this function does not initialize tm but only stores the
values specified. This means that tm should be initialized before the
call. Details differ a bit between different Unix systems. The GNU
libc implementation does not touch those fields which are not explicitly
specified, except that it recomputes the tm_wday and tm_yday field
if any of the year, month, or day elements changed.
This function is available since libc 4.6.8. Linux libc4 and libc5
includes define the prototype unconditionally; glibc2 includes provide
a prototype only when _XOPEN_SOURCE or _GNU_SOURCE are defined. The E
and O locale modifier characters are accepted since libc 5.4.13. The
'y' (year in century) specification is taken to specify a year in the
20th century by libc4 and libc5. It is taken to be a year in the range
1950-2049 by glibc 2.0. It is taken to be a year in 1969-2068 by glibc
2.1.
time(2), scanf(3), setlocale(3), strftime(3)
GNU 1994-09-26 STRPTIME(3)
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