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diff --git a/man3/difftime.3 b/man3/difftime.3 new file mode 100644 index 000000000..21f0090f1 --- /dev/null +++ b/man3/difftime.3 @@ -0,0 +1,61 @@ +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified Sat Jul 24 19:48:17 1993 by Rik Faith (faith@cs.unc.edu) +.TH DIFFTIME 3 1993-07-02 "GNU" "Linux Programmer's Manual" +.SH NAME +difftime \- calculate time difference +.SH SYNOPSIS +.nf +.B #include <time.h> +.sp +.BI "double difftime(time_t " time1 ", time_t " time0 ); +.fi +.SH DESCRIPTION +The \fBdifftime()\fP function returns the number of seconds elapsed +between time \fItime1\fP and time \fItime0\fP, represented as a double. +The two times are specified in calendar time, which represents the time +elapsed since the Epoch +(00:00:00 on January 1, 1970, Coordinated Universal Time (UTC)). +.SH "CONFORMING TO" +SVID 3, BSD 4.3, ISO 9899 +.SH NOTES +This function is required by ANSI C. +On a POSIX system, time_t is an arithmetic type, and one could just +define +.RS +.nf +#define difftime(t1,t0) (double)(t1 - t0) +.fi +.RE +when the possible overflow in the subtraction is not a concern. +.SH "SEE ALSO" +.BR date (1), +.BR gettimeofday (2), +.BR time (2), +.BR ctime (3), +.BR gmtime (3), +.BR localtime (3) |