From cb7fd5031ae61c55e404a06f9f2932ee89a9cde1 Mon Sep 17 00:00:00 2001 From: Alejandro Colomar Date: Thu, 17 Sep 2020 12:42:59 +0200 Subject: [PATCH] system_data_types.7: Add a new page to document system data types The initial version documents sigval, ssize_t, suseconds_t, time_t, timer_t, timespec, and timeval. Signed-off-by: Alejandro Colomar Signed-off-by: Michael Kerrisk --- man7/system_data_types.7 | 280 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 280 insertions(+) create mode 100644 man7/system_data_types.7 diff --git a/man7/system_data_types.7 b/man7/system_data_types.7 new file mode 100644 index 000000000..f94c0f2dd --- /dev/null +++ b/man7/system_data_types.7 @@ -0,0 +1,280 @@ +.\" Copyright (c) 2020 by Alejandro Colomar +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" 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 +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date.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. +.\" %%%LICENSE_END +.\" +.\" +.TH SYSTEM_DATA_TYPES 7 2020-09-13 "Linux" "Linux Programmer's Manual" +.SH NAME +system_data_types \- overview of system data types +.SH DESCRIPTION +.\" TODO: +.\" * Add types +.\" * Curate "See also" +.\" Layout: +.\" A list of type names (the struct/union keyword will be omitted). +.\" Each entry will have the following parts: +.\" * Include +.\" The headers will be in the following order: +.\" 1) The main header that shall define the type +.\" according to the C Standard, +.\" and +.\" the main header that shall define the type +.\" according to POSIX, +.\" in alphabetical order. +.\" ; +.\" 2) All other headers that shall define the type +.\" as described in the previous header(s) +.\" according to the C Standard or POSIX, +.\" in alphabetical order. +.\" *) All headers that define the type +.\" *if* the type is not defined by C nor POSIX, +.\" in alphabetical order. +.\" +.\" * Definition (no "Definition" header) +.\" Only struct/union types will have definition; +.\" typedefs will remain opaque. +.\" +.\" * Description (no "Description" header) +.\" A few lines describing the type. +.\" +.\" * Conforming to +.\" Format: CXY and later; POSIX.1-XXXX and later. +.\" Forget about pre-C99 C standards (i.e., C89/C90) +.\" +.\" * Notes (optional) +.\" +.\" * See also +.TP +.I sigval +.IP +Include: +.IR . +.IP +.EX +union sigval { + int sigval_int; /* Integer value */ + void *sigval_ptr; /* Pointer value */ +}; +.EE +.IP +Data passed with a signal. +.IP +Conforming to: POSIX.1-2001 and later. +.IP +See also: +.BR pthread_sigqueue (3), +.BR sigqueue (3), +.BR sigevent (7) +.\".IP +.\"See also the +.\".I sigevent +.\"structure and the +.\".I siginfo_t +.\"type in this page. +.TP +.I ssize_t +.IP +Include: +.IR ; +or +.I +or +.I +or +.I +or +.I +or +.I +or +.I +or +.I +or +.IR . +.IP +Used for a count of bytes or an error indication. +According to POSIX, it shall be a signed integer type +capable of storing values at least in the range [-1, +.BR SSIZE_MAX ]. +.IP +Conforming to: POSIX.1-2001 and later. +.IP +See also: +.BR read (2), +.BR readlink (2), +.BR readv (2), +.BR recv (2), +.BR send (2), +.BR write (2) +.\".IP FIXME: When size_t is added, uncomment +.\"See also the +.\".I size_t +.\"type in this page. +.TP +.I suseconds_t +.IP +Include: +.IR ; +or +.I +or +.IR . +.IP +Used for time in microseconds. +According to POSIX, it shall be a signed integer type +capable of storing values at least in the range [-1, 1000000]. +.IP +Conforming to: POSIX.1-2001 and later. +.IP +See also the +.I timeval +structure in this page. +.TP +.I time_t +.IP +Include: +.I +or +.IR ; +or +.I +or +.I +or +.I +or +.I +or +.I +or +.I +or +.I +or +.IR . +.IP +Used for time in seconds. +According to POSIX, it shall be an integer type. +.IP +Conforming to: C99 and later; POSIX.1-2001 and later. +.IP +Notes: +.I +defines +.I time_t +since POSIX.1-2008. +.IP +See also: +.BR stime (2), +.BR time (2), +.BR ctime (3), +.BR difftime (3) +.TP +.I timer_t +.IP +Include: +.IR ; +or +.IR . +.IP +Used for timer ID returned by +.BR timer_create (2). +According to POSIX, +there are no defined comparison or assignment operators for this type. +.IP +Conforming to: POSIX.1-2001 and later. +.IP +See also: +.BR timer_create (2), +.BR timer_delete (2), +.BR timer_getoverrun (2), +.BR timer_settime (2) +.TP +.I timespec +.IP +Include: +.IR ; +or +.I +or +.I +or +.I +or +.I +or +.I +or +.IR . +.IP +.EX +struct timespec { + time_t tv_sec; /* Seconds */ + long tv_nsec; /* Nanoseconds */ +}; +.EE +.IP +Describes times in seconds and nanoseconds. +.IP +Conforming to: C11 and later; POSIX.1-2001 and later. +.IP +See also: +.BR clock_gettime (2), +.BR clock_nanosleep (2), +.BR nanosleep (2), +.BR timerfd_gettime (2), +.BR timer_gettime (2) +.TP +.I timeval +.IP +Include: +.IR ; +or +.I +or +.I +or +.IR . +.IP +.EX +struct timeval { + time_t tv_sec; /* Seconds */ + suseconds_t tv_usec; /* Microseconds */ +}; +.EE +.IP +Describes times in seconds and microseconds. +.IP +Conforming to: POSIX.1-2001 and later. +.IP +See also: +.BR gettimeofday (2), +.BR select (2), +.BR utimes (2), +.BR adjtime (3), +.BR futimes (3), +.BR timeradd (3) +.SH NOTES +The structures described in this manual page shall contain, +at least, the members shown in their definition, in no particular order.