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The ternary if-then-else operator generally has the following syntax: E ? X : Y where E is a Boolean expression and if true, the statement is assigned the value Y.
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getdate(3) [redhat man page]

GETDATE(3)						     Linux Programmer's Manual							GETDATE(3)

NAME
getdate() - convert a string to struct tm SYNOPSIS
#define _XOPEN_SOURCE #define _XOPEN_SOURCE_EXTENDED #include <time.h> struct tm *getdate (const char *string); extern int getdate_err; #define _GNU_SOURCE #include <time.h> int getdate_r (const char *string, struct tm *res); DESCRIPTION
The function getdate() converts a string pointed to by string into the tm structure that it returns. This tm structure may be found in static storage, so that it will be overwritten by the next call. In contrast to strptime(3), (which has a format argument), getdate() uses the formats found in the file of which the full path name is given in the environment variable DATEMSK. The first line in the file that matches the given input string is used for the conversion. The matching is done case insensitively. Superfluous whitespace, either in the pattern or in the string to be converted, is ignored. The conversion specifications that a pattern can contain are those given for strptime(3). One more conversion specification is accepted: %Z Timezone name. When %Z is given, the value to be returned is initialised to the broken-down time corresponding to the current time in the given time zone. Otherwise, it is initialised to the broken-down time corresponding to the current local time. When only the weekday is given, the day is taken to be the first such day on or after today. When only the month is given (and no year), the month is taken to be the first such month equal to or after the current month. If no day is given, it is the first day of the month. When no hour, minute and second are given, the current hour, minute and second are taken. If no date is given, but we know the hour, then that hour is taken to be the first such hour equal to or after the current hour. RETURN VALUE
When successful, this function returns a pointer to a struct tm. Otherwise, it returns NULL and sets the global variable getdate_err. Changes to errno are unspecified. The following values for getdate_err are defined: 1 The DATEMSK environment variable is null or undefined. 2 The template file cannot be opened for reading. 3 Failed to get file status information. 4 The template file is not a regular file. 5 An error is encountered while reading the template file. 6 Memory allocation failed (not enough memory available). 7 There is no line in the file that matches the input. 8 Invalid input specification. NOTES
Since getdate() is not reentrant because of the use of getdate_err and the static buffer to return the result in, glibc provides a thread- safe variant. The functionality is the same. The result is returned in the buffer pointed to by res and in case of an error the return value is nonzero with the same values as given above for getdate_err. The POSIX 1003.1-2001 specification for strptime() contains conversion specifications using the %E or %O modifier, while such specifica- tions are not given for getdate(). The glibc implementation implements getdate() using strptime() so that automatically precisely the same conversions are supported by both. The glibc implementation does not support the %Z conversion specification. ENVIRONMENT
DATEMSK File containing format patterns. TZ, LC_TIME Variables used by strptime(). CONFORMING TO
ISO 9899, POSIX 1003.1-2001 SEE ALSO
localtime(3), strftime(3), strptime(3), time(3) 2001-12-26 GETDATE(3)

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GETDATE(3)						     Linux Programmer's Manual							GETDATE(3)

NAME
getdate, getdate_r - convert a date-plus-time string to broken-down time SYNOPSIS
#define _XOPEN_SOURCE 500 #include <time.h> struct tm *getdate(const char *string); extern int getdate_err; #define _GNU_SOURCE #include <time.h> int getdate_r(const char *string, struct tm *res); DESCRIPTION
The function getdate() converts a string representation of a date and time, contained in the buffer pointed to by string, into a broken- down time. The broken-down time is stored in a tm structure, and a pointer to this structure is returned as the function result. This tm structure is allocated in static storage, and consequently it will be overwritten by further calls to getdate(). In contrast to strptime(3), (which has a format argument), getdate() uses the formats found in the file whose full pathname is given in the environment variable DATEMSK. The first line in the file that matches the given input string is used for the conversion. The matching is done case insensitively. Superfluous whitespace, either in the pattern or in the string to be converted, is ignored. The conversion specifications that a pattern can contain are those given for strptime(3). One more conversion specification is specified in POSIX.1-2001: %Z Timezone name. This is not implemented in glibc. When %Z is given, the structure containing the broken-down time is initialized with values corresponding to the current time in the given timezone. Otherwise, the structure is initialized to the broken-down time corresponding to the current local time (as by a call to local- time(3)). When only the weekday is given, the day is taken to be the first such day on or after today. When only the month is given (and no year), the month is taken to be the first such month equal to or after the current month. If no day is given, it is the first day of the month. When no hour, minute and second are given, the current hour, minute and second are taken. If no date is given, but we know the hour, then that hour is taken to be the first such hour equal to or after the current hour. getdate_r() is a GNU extension that provides a reentrant version of getdate(). Rather than using a global variable to report errors and a static buffer to return the broken down time, it returns errors via the function result value, and returns the resulting broken-down time in the caller-allocated buffer pointed to by the argument res. RETURN VALUE
When successful, getdate() returns a pointer to a struct tm. Otherwise, it returns NULL and sets the global variable getdate_err to one of the error numbers shown below. Changes to errno are unspecified. On success getdate_r() returns 0; on error it returns one of the error numbers shown below. ERRORS
The following errors are returned via getdate_err (for getdate()) or as the function result (for getdate_r()): 1 The DATEMSK environment variable is not defined, or its value is an empty string. 2 The template file specified by DATEMSK cannot be opened for reading. 3 Failed to get file status information. 4 The template file is not a regular file. 5 An error was encountered while reading the template file. 6 Memory allocation failed (not enough memory available). 7 There is no line in the file that matches the input. 8 Invalid input specification. ENVIRONMENT
DATEMSK File containing format patterns. TZ, LC_TIME Variables used by strptime(3). CONFORMING TO
POSIX.1-2001. NOTES
The POSIX.1-2001 specification for strptime(3) contains conversion specifications using the %E or %O modifier, while such specifications are not given for getdate(). In glibc, getdate() is implemented using strptime(3), so that precisely the same conversions are supported by both. EXAMPLE
The program below calls getdate() for each of its command-line arguments, and for each call displays the values in the fields of the returned tm structure. The following shell session demonstrates the operation of the program: $ TFILE=$PWD/tfile $ echo '%A' > $TFILE # Full weekday name $ echo '%T' >> $TFILE # ISO date (YYYY-MM-DD) $ echo '%F' >> $TFILE # Time (HH:MM:SS) $ date $ export DATEMSK=$TFILE $ ./a.out Tuesday '2009-12-28' '12:22:33' Sun Sep 7 06:03:36 CEST 2008 Call 1 ("Tuesday") succeeded: tm_sec = 36 tm_min = 3 tm_hour = 6 tm_mday = 9 tm_mon = 8 tm_year = 108 tm_wday = 2 tm_yday = 252 tm_isdst = 1 Call 2 ("2009-12-28") succeeded: tm_sec = 36 tm_min = 3 tm_hour = 6 tm_mday = 28 tm_mon = 11 tm_year = 109 tm_wday = 1 tm_yday = 361 tm_isdst = 0 Call 3 ("12:22:33") succeeded: tm_sec = 33 tm_min = 22 tm_hour = 12 tm_mday = 7 tm_mon = 8 tm_year = 108 tm_wday = 0 tm_yday = 250 tm_isdst = 1 Program source #define _GNU_SOURCE 500 #include <time.h> #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { struct tm *tmp; int j; for (j = 1; j < argc; j++) { tmp = getdate(argv[j]); if (tmp == NULL) { printf("Call %d failed; getdate_err = %d ", j, getdate_err); continue; } printf("Call %d ("%s") succeeded: ", j, argv[j]); printf(" tm_sec = %d ", tmp->tm_sec); printf(" tm_min = %d ", tmp->tm_min); printf(" tm_hour = %d ", tmp->tm_hour); printf(" tm_mday = %d ", tmp->tm_mday); printf(" tm_mon = %d ", tmp->tm_mon); printf(" tm_year = %d ", tmp->tm_year); printf(" tm_wday = %d ", tmp->tm_wday); printf(" tm_yday = %d ", tmp->tm_yday); printf(" tm_isdst = %d ", tmp->tm_isdst); } exit(EXIT_SUCCESS); } SEE ALSO
time(2), localtime(3), setlocale(3), strftime(3), strptime(3), feature_test_macros(7) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2008-09-07 GETDATE(3)

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