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101 lines
2.6 KiB
Plaintext
101 lines
2.6 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "TZSET" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" tzset
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.SH NAME
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daylight, timezone, tzname, tzset \- set timezone conversion information
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.SH SYNOPSIS
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.LP
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\fB#include <time.h>
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.br
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.sp
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\fP
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.LP
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\fBextern int daylight;
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.br
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extern long timezone;
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.br
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\fP
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.LP
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\fBextern char *tzname[2];
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.br
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void tzset(void); \fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fItzset\fP() function shall use the value of the environment
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variable \fITZ\fP to set time conversion information used by
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\fIctime\fP() , \fIlocaltime\fP() , \fImktime\fP() , and \fIstrftime\fP()
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\&. If \fITZ\fP is absent from the
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environment, implementation-defined default timezone information shall
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be used.
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.LP
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The \fItzset\fP() function shall set the external variable \fItzname\fP
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as follows:
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.sp
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.RS
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.nf
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\fBtzname[0] = "\fP\fIstd\fP\fB";
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tzname[1] = "\fP\fIdst\fP\fB";
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\fP
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.fi
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.RE
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.LP
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where \fIstd\fP and \fIdst\fP are as described in the Base Definitions
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volume of IEEE\ Std\ 1003.1-2001, Chapter 8, Environment Variables.
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.LP
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The \fItzset\fP() function also shall set the external variable \fIdaylight\fP
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to 0 if Daylight Savings Time conversions should
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never be applied for the timezone in use; otherwise, non-zero. The
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external variable \fItimezone\fP shall be set to the
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difference, in seconds, between Coordinated Universal Time (UTC) and
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local standard time.
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.SH RETURN VALUE
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.LP
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The \fItzset\fP() function shall not return a value.
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.SH ERRORS
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.LP
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No errors are defined.
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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Example \fITZ\fP variables and their timezone differences are given
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in the table below:
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.TS C
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center; l l.
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TZ timezone
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EST5EDT 5*60*60
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GMT0 0*60*60
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JST-9 -9*60*60
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MET-1MEST -1*60*60
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MST7MDT 7*60*60
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PST8PDT 8*60*60
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.TE
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIctime\fP() , \fIlocaltime\fP() , \fImktime\fP() , \fIstrftime\fP()
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, the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, Chapter 8, Environment Variables, \fI<time.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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