sysinfo — return system information
#include <sys/sysinfo.h>
int
sysinfo( |
struct sysinfo *info); |
sysinfo() returns certain
statistics on memory and swap usage, as well as the load
average.
Until Linux 2.3.16, sysinfo() returned information in the
following structure:
struct sysinfo { long uptime;unsigned long loads[3];unsigned long totalram;unsigned long freeram;unsigned long sharedram;unsigned long bufferram;unsigned long totalswap;unsigned long freeswap;unsigned short procs;char _f[22];};
In the above structure, the sizes of the memory and swap fields are given in bytes.
Since Linux 2.3.23 (i386) and Linux 2.3.48 (all architectures) the structure is:
struct sysinfo { long uptime; /* Seconds since boot */ unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ unsigned long totalram; /* Total usable main memory size */ unsigned long freeram; /* Available memory size */ unsigned long sharedram; /* Amount of shared memory */ unsigned long bufferram; /* Memory used by buffers */ unsigned long totalswap; /* Total swap space size */ unsigned long freeswap; /* Swap space still available */ unsigned short procs; /* Number of current processes */ unsigned long totalhigh; /* Total high memory size */ unsigned long freehigh; /* Available high memory size */ unsigned int mem_unit; /* Memory unit size in bytes */ char _f[20−2*sizeof(long)−sizeof(int)]; /* Padding to 64 bytes */ };
In the above structure, sizes of the memory and swap
fields are given as multiples of mem_unit bytes.
On success, sysinfo()
returns zero. On error, −1 is returned, and
errno is set to indicate the
cause of the error.
This function is Linux-specific, and should not be used in programs intended to be portable.
All of the information provided by this system call is
also available via /proc/meminfo and /proc/loadavg.
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright (C) 2016, Michael Kerrisk <mtk.manpagesgmail.com> Based on an earlier version of the page where a few pieces were copyright (C) 1993 by Dan Miner (dminernyx.cs.du.edu) and subsequently others (see old changelog below). The structure definitions are taken more or less straight from the kernel source files. %%%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 Modified Sat Jul 24 12:35:12 1993 by Rik Faith <faithcs.unc.edu> Modified Tue Oct 22 22:29:51 1996 by Eric S. Raymond <esrthyrsus.com> Modified Mon Aug 25 16:06:11 1997 by Nicolás Lichtmaier <nickdebian.org> |