From 1c382af469f840944a5b034be61f197b3c854659 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Thu, 20 Apr 2006 21:07:10 +0000 Subject: [PATCH] Point out more explicitly that 'tz' argument should normally be NULL. Various other minor edits and formatting fixes. --- man2/gettimeofday.2 | 71 ++++++++++++++++++++++++--------------------- 1 file changed, 38 insertions(+), 33 deletions(-) diff --git a/man2/gettimeofday.2 b/man2/gettimeofday.2 index 4adf0994e..495015ae1 100644 --- a/man2/gettimeofday.2 +++ b/man2/gettimeofday.2 @@ -60,14 +60,14 @@ argument is a (as specified in .IR ): .sp +.in +0.25i .nf struct timeval { -.in +8 -time_t tv_sec; /* seconds */ -suseconds_t tv_usec; /* microseconds */ -.in -8 + time_t tv_sec; /* seconds */ + suseconds_t tv_usec; /* microseconds */ }; .fi +.in -0.25i .sp and gives the number of seconds and microseconds since the Epoch (see .BR time (2)). @@ -76,16 +76,31 @@ The argument is a .IR "struct timezone" : .sp +.in +0.25i .nf struct timezone { -.in +8 -int tz_minuteswest; /* minutes W of Greenwich */ -int tz_dsttime; /* type of dst correction */ -.in -8 + int tz_minuteswest; /* minutes W of Greenwich */ + int tz_dsttime; /* type of dst correction */ }; .fi +.in -0.25i .PP -The use of the timezone struct is obsolete: the +If either +.I tv +or +.I tz +is NULL, the corresponding structure is not set or returned. +.\" The following is covered under EPERM below: +.\" .PP +.\" Only the superuser may use +.\" .BR settimeofday (). +.PP +The use of the +.I timezone +structure is obsolete; the +.I tz +argument should normally be specfied as NULL. +The .I tz_dsttime field has never been used under Linux; it has not been and will not be supported by libc or glibc. @@ -102,28 +117,27 @@ it does not indicate that DST is in force, it just selects an algorithm.) The daylight saving time algorithms defined are as follows : .PP -.ta 14 -\fB DST_NONE\fP /* not on dst */ +\fB DST_NONE\fP /* not on dst */ .br -\fB DST_USA\fP /* USA style dst */ +\fB DST_USA\fP /* USA style dst */ .br -\fB DST_AUST\fP /* Australian style dst */ +\fB DST_AUST\fP /* Australian style dst */ .br -\fB DST_WET\fP /* Western European dst */ +\fB DST_WET\fP /* Western European dst */ .br -\fB DST_MET\fP /* Middle European dst */ +\fB DST_MET\fP /* Middle European dst */ .br -\fB DST_EET\fP /* Eastern European dst */ +\fB DST_EET\fP /* Eastern European dst */ .br -\fB DST_CAN\fP /* Canada */ +\fB DST_CAN\fP /* Canada */ .br -\fB DST_GB\fP /* Great Britain and Eire */ +\fB DST_GB\fP /* Great Britain and Eire */ .br -\fB DST_RUM\fP /* Rumania */ +\fB DST_RUM\fP /* Rumania */ .br -\fB DST_TUR\fP /* Turkey */ +\fB DST_TUR\fP /* Turkey */ .br -\fB DST_AUSTALT\fP /* Australian style with shift in 1986 */ +\fB DST_AUSTALT\fP /* Australian style with shift in 1986 */ .PP Of course it turned out that the period in which Daylight Saving Time is in force cannot be given @@ -155,28 +169,19 @@ The following macros are defined to operate on a .IR "struct timeval" : .sp .nf -#define timerisset(tvp)\\ +#define timerisset(tvp)\\ .ti +8 ((tvp)\->tv_sec || (tvp)\->tv_usec) -#define timercmp(tvp, uvp, cmp)\\ +#define timercmp(tvp, uvp, cmp)\\ .in +8 ((tvp)\->tv_sec cmp (uvp)\->tv_sec ||\\ (tvp)\->tv_sec == (uvp)\->tv_sec &&\\ (tvp)\->tv_usec cmp (uvp)\->tv_usec) .in -8 -#define timerclear(tvp)\\ +#define timerclear(tvp)\\ .ti +8 ((tvp)\->tv_sec = (tvp)\->tv_usec = 0) .fi -.PP -If either -.I tv -or -.I tz -is null, the corresponding structure is not set or returned. -.PP -Only the superuser may use -.BR settimeofday (). .SH "RETURN VALUE" .BR gettimeofday () and