.fp 5 CW

.de Af

.ds ;G \\*(;G\\f\\$1\\$3\\f\\$2

.if !\\$4 .Af \\$2 \\$1 "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"

..

.de aF

.ie \\$3 .ft \\$1

.el \{\

.ds ;G \&

.nr ;G \\n(.f

.Af "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"

\\*(;G

.ft \\n(;G \}

..

.de L

.aF 5 \\n(.f "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de LR

.aF 5 1 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de RL

.aF 1 5 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"

..

.de EX \" start example

.ta 1i 2i 3i 4i 5i 6i

.PP

.RS

.PD 0

.ft 5

.nf

..

.de EE \" end example

.fi

.ft

.PD

.RE

.PP

..

.TH TM 3

.SH NAME

tv \- high resolution time support

.SH SYNOPSIS

.L "#include <tv.h>"

.SH DESCRIPTION

The

.I tv

library supports high resolution

.B Tv_t

time specifications.

.SS Tv_t

contains these elements:

.TP

.L unsigned

.L _ast_int4_t

.L tv_sec

Seconds since the epoch.

.TP

.L unsigned

.L _ast_int4_t

.L tv_nsec

Nanosecond resolution.

.PP

In practice resolution is much coarser than 1 nanosecond.

Systems that only support 1 second resolution always set

.L tv_nsec

to 0.

.SS "int tvgettime(Tv_t* tv)"

Sets

.L tv

to the current time.

.L 0

is returned on success,

.L -1

on error.

.SS "int tvsettime(const Tv_t* tv)"

Sets the system time to

.LR tv .

The caller must have sufficient privilege.

.L 0

is returned on success,

.L -1

on error.

.SS "int tvcmp(const Tv_t* av, const Tv_t* bv)"

Compares the times

.L av

and

.L bv

and returns

.L -1

if

.L av

is less than

.LR bv ,

.L 0

if

.L av

is equal to

.LR bv ,

and

.L 1

if

.L av

is greater than

.LR bv .

.SS "time_t tvgetatime(Tv_t* tv, const struct stat* st)"

.SS "time_t tvgetmtime(Tv_t* tv, const struct stat* st)"

.SS "time_t tvgetctime(Tv_t* tv, const struct stat* st)"

These macros set

.L tv

to the

.L st

the access, modify, or change time, respectively.

The seconds portion of

.L tv

is returned.

.SS "time_t tvsetatime(Tv_t* tv, struct stat* st)"

.SS "time_t tvsetmtime(Tv_t* tv, struct stat* st)"

.SS "time_t tvsetctime(Tv_t* tv, struct stat* st)"

These macros set the

.L st

access, modify, or change time, respectively, to

.LR tv .

The seconds portion of

.L tv

is returned.

.SS "int tvtouch(const char* path, const Tv_t* av, const Tv_t* mv, const Tv_t* cv, int copy)"

Sets the file

.L path

access time from

.LR av ,

modify time from

.LR mv ,

and change time from

.LR cv .

Any of

.LR av ,

.LR mv ,

and

.L cv

may be 0; the corresponding file time will retain the previous value if

.L path

exists and

.L copy

is

.L 1 ;

otherwise the corresponding file time will be set to the current time.

.L 0

is returned on success,

.L -1

on error.

.SS "int tvsleep(const Tv_t* tv, Tv_t* rv)"

Pauses execution for

.L tv

time.

.L 0

is returned if the full

.L tv

amount has expired.

Otherwise

.L -1

is returned and

.LR rv ,

if not 0, is set to the sleep time remaining.

.SH "RETURN VALUE"

Except for

.LR tvcmp() ,

an error return of

.L -1

also sets

.L errno

to the corresponding error code.

.SH "SEE ALSO"

tm(3)