Manual Pages for Linux CentOS command on man sysinfo
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Manual Pages for Linux CentOS command on man sysinfo

SYSINFO(2) Linux Programmer's Manual SYSINFO(2)

NAME

sysinfo - returns information on overall system statistics SYNOPSIS

#include int sysinfo(struct sysinfo *info); DESCRIPTION Until Linux 2.3.16, sysinfo() used to return information in the follow‐ ing structure: 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 */ char f[22]; /* Pads structure to 64 bytes */ }; and the sizes were given in bytes. Since Linux 2.3.23 (i386), 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 memunit; /* Memory unit size in bytes */

char f[20-2*sizeof(long)-sizeof(int)]; /* Padding to 64 bytes */ }; and the sizes are given as multiples of memunit bytes. sysinfo() provides a simple way of getting overall system statistics. This is more portable than reading /dev/kmem. RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set appropriately. ERRORS EFAULT pointer to struct sysinfo is invalid CONFORMING TO

This function is Linux-specific, and should not be used in programs intended to be portable. The Linux kernel has a sysinfo() system call since 0.98.pl6. Linux libc contains a sysinfo() routine since 5.3.5, and glibc has one since 1.90. SEE ALSO proc(5) COLOPHON

This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can

be found at http://www.kernel.org/doc/man-pages/.

Linux 2012-05-05 SYSINFO(2)




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