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115 lines
2.1 KiB
Groff
115 lines
2.1 KiB
Groff
.TH CTIME 3
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.SH NAME
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ctime, localtime, gmtime, asctime, tm2sec \- convert date and time
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.SH SYNOPSIS
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.B #include <u.h>
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.br
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.B #include <libc.h>
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.PP
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.ta \w'\fLchar* 'u
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.B
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char* ctime(long clock)
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.PP
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.B
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Tm* localtime(long clock)
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.PP
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.B
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Tm* gmtime(long clock)
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.PP
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.B
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char* asctime(Tm *tm)
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.PP
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.B
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long tm2sec(Tm *tm)
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.SH DESCRIPTION
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.I Ctime
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converts a time
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.I clock
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such as returned by
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.MR time (3)
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into
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.SM ASCII
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(sic)
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and returns a pointer to a
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30-byte string
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in the following form.
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All the fields have constant width.
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.PP
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.B
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Wed Aug 5 01:07:47 EST 1973\en\e0
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.PP
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.I Localtime
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and
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.I gmtime
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return pointers to structures containing
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the broken-down time.
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.I Localtime
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corrects for the time zone and possible daylight savings time;
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.I gmtime
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converts directly to GMT.
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.I Asctime
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converts a broken-down time to
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.SM ASCII
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and returns a pointer
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to a 30-byte string.
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.IP
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.EX
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.ta 6n +\w'char 'u +\w'zone[4]; 'u
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typedef
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struct {
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int sec; /* seconds (range 0..59) */
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int min; /* minutes (0..59) */
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int hour; /* hours (0..23) */
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int mday; /* day of the month (1..31) */
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int mon; /* month of the year (0..11) */
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int year; /* year A.D. \- 1900 */
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int wday; /* day of week (0..6, Sunday = 0) */
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int yday; /* day of year (0..365) */
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char zone[4]; /* time zone name */
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int tzoff; /* time zone delta from GMT */
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} Tm;
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.EE
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.PP
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.I Tm2sec
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converts a broken-down time to
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seconds since the start of the epoch.
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It ignores
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.BR wday ,
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and assumes the local time zone
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if
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.B zone
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is not
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.BR GMT .
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.SH SOURCE
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.B \*9/src/lib9/ctime.c
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.br
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.B \*9/src/lib9/tm2sec.c
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.SH "SEE ALSO"
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.MR date (1) ,
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.MR time (3)
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.SH BUGS
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The return values point to static data
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whose content is overwritten by each call.
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.PP
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Daylight Savings Time is ``normal'' in the Southern hemisphere.
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.PP
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These routines are not equipped to handle non-\c
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.SM ASCII
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text, and are provincial anyway.
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.PP
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To avoid name conflicts with the underlying system,
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.IR ctime ,
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.IR localtime ,
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.IR gmtime ,
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.IR asctime ,
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and
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.I tm2sec
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are preprocessor macros defined as
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.IR p9ctime ,
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.IR p9localtime ,
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.IR p9gmtime ,
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.IR p9asctime ,
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and
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.IR p9tm2sec ;
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see
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.MR intro (3) .
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