getdate_r(3)

1GETDATE(3)                 Linux Programmer's Manual                GETDATE(3)
2
3
4

NAME

6       getdate - convert a string to struct tm
7

SYNOPSIS

9       #define _XOPEN_SOURCE
10       #define _XOPEN_SOURCE_EXTENDED
11       #include <time.h>
12
13       struct tm *getdate (const char *string);
14
15       extern int getdate_err;
16
17
18       #define _GNU_SOURCE
19       #include <time.h>
20
21       int getdate_r (const char *string, struct tm *res);
22

DESCRIPTION

24       The  function getdate() converts a string pointed to by string into the
25       tm structure that it returns.  This tm structure may be found in static
26       storage, so that it will be overwritten by the next call.
27
28       In  contrast  to  strptime(3), (which has a format argument), getdate()
29       uses the formats found in the file of which the full pathname is  given
30       in  the  environment variable DATEMSK.  The first line in the file that
31       matches the given input string is used for the conversion.
32
33       The matching  is  done  case  insensitively.   Superfluous  whitespace,
34       either in the pattern or in the string to be converted, is ignored.
35
36       The  conversion  specifications  that  a  pattern can contain are those
37       given for strptime(3).  One more conversion specification is accepted:
38
39       %Z     Timezone name.
40
41       When %Z is given, the value to be returned is initialised to  the  bro‐
42       ken-down time corresponding to the current time in the given time zone.
43       Otherwise, it is initialised to the broken-down time  corresponding  to
44       the current local time.
45
46       When  only  the weekday is given, the day is taken to be the first such
47       day on or after today.
48
49       When only the month is given (and no year), the month is  taken  to  be
50       the first such month equal to or after the current month.  If no day is
51       given, it is the first day of the month.
52
53       When no hour, minute and second are given, the current hour, minute and
54       second are taken.
55
56       If  no  date is given, but we know the hour, then that hour is taken to
57       be the first such hour equal to or after the current hour.
58

RETURN VALUE

60       When successful, this function returns a pointer to a struct tm.   Oth‐
61       erwise,  it  returns  NULL  and  sets  the global variable getdate_err.
62       Changes to errno are unspecified.  The following values for getdate_err
63       are defined:
64
65       1   The DATEMSK environment variable is null or undefined.
66
67       2   The template file cannot be opened for reading.
68
69       3   Failed to get file status information.
70
71       4   The template file is not a regular file.
72
73       5   An error is encountered while reading the template file.
74
75       6   Memory allocation failed (not enough memory available).
76
77       7   There is no line in the file that matches the input.
78
79       8   Invalid input specification.
80

NOTES

82       Since  getdate() is not reentrant because of the use of getdate_err and
83       the static buffer to return the result in, glibc provides a thread-safe
84       variant.  The functionality is the same.  The result is returned in the
85       buffer pointed to by res and in case of an error the  return  value  is
86       non-zero with the same values as given above for getdate_err.
87
88       The POSIX.1-2001 specification for strptime() contains conversion spec‐
89       ifications using the %E or %O modifier, while such  specifications  are
90       not given for getdate().  The glibc implementation implements getdate()
91       using strptime() so that automatically precisely the  same  conversions
92       are supported by both.
93
94       The  glibc implementation does not support the %Z conversion specifica‐
95       tion.
96

ENVIRONMENT

98       DATEMSK
99              File containing format patterns.
100
101       TZ, LC_TIME
102              Variables used by strptime().
103

CONFORMING TO

105       POSIX.1-2001
106