SYSINFO

SYSINFO

NAME SYNOPSIS DESCRIPTION RETURN VALUE ERRORS CONFORMING TO SEE ALSO

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 following 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 mem_unit; / Memory unit size in bytes / char _f[20-2*sizeof(long)-sizeof(int)?; / Padding for libc5 */ };

and the sizes are given as multiples of mem_unit bytes.

sysinfo provides a simple way of getting overall system statistics. This is more portable than reading /dev/kmem. For an example of its use, see intro(2).

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)