PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

STRPTIME(3P)              POSIX Programmer's Manual             STRPTIME(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       strptime — date and time conversion

SYNOPSIS         top

       #include <time.h>

       char *strptime(const char *restrict buf, const char *restrict format,
           struct tm *restrict tm);

DESCRIPTION         top

       The strptime() function shall convert the character string pointed to
       by buf to values which are stored in the tm structure pointed to by
       tm, using the format specified by format.

       The format is composed of zero or more directives. Each directive is
       composed of one of the following: one or more white-space characters
       (as specified by isspace()); an ordinary character (neither '%' nor a
       white-space character); or a conversion specification.

       Each conversion specification is introduced by the '%' character
       after which the following appear in sequence:

        *  An optional flag, the zero character ('0') or the <plus-sign>
           character ('+'), which is ignored.

        *  An optional field width. If a field width is specified, it shall
           be interpreted as a string of decimal digits that will determine
           the maximum number of bytes converted for the conversion rather
           than the number of bytes specified below in the description of
           the conversion specifiers.

        *  An optional E or O modifier.

        *  A terminating conversion specifier character that indicates the
           type of conversion to be applied.

       The conversions are determined using the LC_TIME category of the
       current locale. The application shall ensure that there is white-
       space or other non-alphanumeric characters between any two conversion
       specifications unless all of the adjacent conversion specifications
       convert a known, fixed number of characters. In the following list,
       the maximum number of characters scanned (excluding the one matching
       the next directive) is as follows:

        *  If a maximum field width is specified, then that number

        *  Otherwise, the pattern "{x}" indicates that the maximum is x

        *  Otherwise, the pattern "[x,y]" indicates that the value shall
           fall within the range given (both bounds being inclusive), and
           the maximum number of characters scanned shall be the maximum
           required to represent any value in the range without leading
           zeros and without a leading <plus-sign>

       The following conversion specifiers are supported.

       The results are unspecified if a modifier is specified with a flag or
       with a minimum field width, or if a field width is specified for any
       conversion specifier other than C, F, or Y.

       a       The day of the week, using the locale's weekday names; either
               the abbreviated or full name may be specified.

       A       Equivalent to %a.

       b       The month, using the locale's month names; either the
               abbreviated or full name may be specified.

       B       Equivalent to %b.

       c       Replaced by the locale's appropriate date and time
               representation.

       C       All but the last two digits of the year {2}; leading zeros
               shall be permitted but shall not be required. A leading '+'
               or '−' character shall be permitted before any leading zeros
               but shall not be required.

       d       The day of the month [01,31]; leading zeros shall be
               permitted but shall not be required.

       D       The date as %m/%d/%y.

       e       Equivalent to %d.

       h       Equivalent to %b.

       H       The hour (24-hour clock) [00,23]; leading zeros shall be
               permitted but shall not be required.

       I       The hour (12-hour clock) [01,12]; leading zeros shall be
               permitted but shall not be required.

       j       The day number of the year [001,366]; leading zeros shall be
               permitted but shall not be required.

       m       The month number [01,12]; leading zeros shall be permitted
               but shall not be required.

       M       The minute [00,59]; leading zeros shall be permitted but
               shall not be required.

       n       Any white space.

       p       The locale's equivalent of a.m. or p.m.

       r       12-hour clock time using the AM/PM notation if t_fmt_ampm is
               not an empty string in the LC_TIME portion of the current
               locale; in the POSIX locale, this shall be equivalent to
               %I:%M:%S %p.

       R       The time as %H:%M.

       S       The seconds [00,60]; leading zeros shall be permitted but
               shall not be required.

       t       Any white space.

       T       The time as %H:%M:%S.

       U       The week number of the year (Sunday as the first day of the
               week) as a decimal number [00,53]; leading zeros shall be
               permitted but shall not be required.

       w       The weekday as a decimal number [0,6], with 0 representing
               Sunday.

       W       The week number of the year (Monday as the first day of the
               week) as a decimal number [00,53]; leading zeros shall be
               permitted but shall not be required.

       x       The date, using the locale's date format.

       X       The time, using the locale's time format.

       y       The last two digits of the year. When format contains neither
               a C conversion specifier nor a Y conversion specifier, values
               in the range [69,99] shall refer to years 1969 to 1999
               inclusive and values in the range [00,68] shall refer to
               years 2000 to 2068 inclusive; leading zeros shall be
               permitted but shall not be required. A leading '+' or '−'
               character shall be permitted before any leading zeros but
               shall not be required.

               Note:     It is expected that in a future version of this
                         standard the default century inferred from a
                         2-digit year will change. (This would apply to all
                         commands accepting a 2-digit year as input.)

       Y       The full year {4}; leading zeros shall be permitted but shall
               not be required. A leading '+' or '−' character shall be
               permitted before any leading zeros but shall not be required.

       %       Replaced by %.

   Modified Conversion Specifiers
       Some conversion specifiers can be modified by the E and O modifier
       characters to indicate that an alternative format or specification
       should be used rather than the one normally used by the unmodified
       conversion specifier. If the alternative format or specification does
       not exist in the current locale, the behavior shall be as if the
       unmodified conversion specification were used.

       %Ec     The locale's alternative appropriate 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.

       %Od     The day of the month using the locale's alternative numeric
               symbols; leading zeros shall be permitted but shall not be
               required.

       %Oe     Equivalent to %Od.

       %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.

       A conversion specification composed of white-space characters is
       executed by scanning input up to the first character that is not
       white-space (which remains unscanned), or until no more characters
       can be scanned.

       A conversion specification that is an ordinary character is executed
       by scanning the next character from the buffer. If the character
       scanned from the buffer differs from the one comprising the
       directive, the directive fails, and the differing and subsequent
       characters remain unscanned.

       A series of conversion specifications composed of %n, %t, white-space
       characters, or any combination is executed by scanning up to the
       first character that is not white space (which remains unscanned), or
       until no more characters can be scanned.

       Any other conversion specification is executed by scanning characters
       until a character matching the next directive is scanned, or until no
       more characters can be scanned. These characters, except the one
       matching the next directive, are then compared to the locale values
       associated with the conversion specifier. If a match is found, values
       for the appropriate tm structure members are set to values
       corresponding to the locale information. Case is ignored when
       matching items in buf such as month or weekday names. If no match is
       found, strptime() fails and no more characters are scanned.

RETURN VALUE         top

       Upon successful completion, strptime() shall return a pointer to the
       character following the last character parsed. Otherwise, a null
       pointer shall be returned.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

   Convert a Data-Plus-Time String to Broken-Down Time and Then into Seconds
       The following example demonstrates the use of strptime() to convert a
       string into broken-down time. The broken-down time is then converted
       into seconds since the Epoch using mktime().

           #include <time.h>
           ...

           struct tm tm;
           time_t t;

           if (strptime("6 Dec 2001 12:33:45", "%d %b %Y %H:%M:%S", &tm) == NULL)
               /* Handle error */;

           printf("year: %d; month: %d; day: %d;\n",
                   tm.tm_year, tm.tm_mon, tm.tm_mday);
           printf("hour: %d; minute: %d; second: %d\n",
                   tm.tm_hour, tm.tm_min, tm.tm_sec);
           printf("week day: %d; year day: %d\n", tm.tm_wday, tm.tm_yday);

           tm.tm_isdst = −1;      /* Not set by strptime(); tells mktime()
                                     to determine whether daylight saving time
                                     is in effect */
           t = mktime(&tm);
           if (t == −1)
               /* Handle error */;
           printf("seconds since the Epoch: %ld\n", (long) t);"

APPLICATION USAGE         top

       Several ``equivalent to'' formats and the special processing of
       white-space characters are provided in order to ease the use of
       identical format strings for strftime() and strptime().

       It should be noted that dates constructed by the strftime() function
       with the %Y or %C%y conversion specifiers may have values larger than
       9999. If the strptime() function is used to read such values using
       %C%y or %Y, the year values will be truncated to four digits.
       Applications should use %+w%y or %+xY with w and x set large enough
       to contain the full value of any years that will be printed or
       scanned.

       See also the APPLICATION USAGE section in strftime(3p).

       It is unspecified whether multiple calls to strptime() using the same
       tm structure will update the current contents of the structure or
       overwrite all contents of the structure. Conforming applications
       should make a single call to strptime() with a format and all data
       needed to completely specify the date and time being converted.

RATIONALE         top

       See the RATIONALE section for strftime(3p).

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       fprintf(3p), fscanf(3p), strftime(3p), time(3p)

       The Base Definitions volume of POSIX.1‐2008, time.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) In the event of any discrepancy between this version and
       the original IEEE and The Open Group Standard, the original IEEE and
       The Open Group Standard is the referee document. The original
       Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                        STRPTIME(3P)

Pages that refer to this page: time.h(0p)asctime(3p)clock(3p)ctime(3p)difftime(3p)gmtime(3p)localtime(3p)mktime(3p)strftime(3p)time(3p)