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/*
* sysinfo.c - get kernel info
*
*/
/*
* Written by Gabor Herr <herr@iti.informatik.th-darmstadt.de>.
*
* Copyright (c) 1992, 1993 by Gabor Herr, all rights reserved.
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear in
* supporting documentation, and that may name is not used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. I make no representations
* about the suitability of this software for any purpose. It is
* provided "as is" without express or implied warranty.
*/
/* $Id: sysinfo.c,v 1.3 1993/02/12 11:40:16 gabor Exp $ */
#include "sysinfo.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
static int meminfo_fd;
static int load_fd;
static int loadavg_fd;
static int swaps_fd;
static char buffer[1024];
/* reread rewritten by Ernst Kloppenburg <kloppen@isr.uni-stuttgart.de> */
/* Now works with Linux 2.2 */
static void reread( int fd, char *message )
{
int i;
int bytesread;
if ( lseek( fd, 0L, 0 ) == 0 ) {
bytesread = read( fd, buffer, sizeof(buffer) - 1 );
if ( bytesread < (sizeof(buffer) - 1) ) {
buffer[bytesread] = 0x0;
return;
}
}
perror(message);
exit(1);
}
static int getentry(const char *tag, const char *bufptr) {
char *tail;
int retval, len = strlen(tag);
while (bufptr) {
if (*bufptr == '\n') bufptr++;
if (!strncmp(tag, bufptr, len)) {
retval = strtol(bufptr + len, &tail, 10);
if (tail == bufptr + len) {
return -1;
} else {
return retval;
}
}
bufptr = strchr( bufptr, '\n' );
}
return -1;
}
void get_meminfo( int *swapdevs, struct meminfo *result )
{
int i;
char *bufptr;
int res;
int sw_size, sw_used;
reread( meminfo_fd, "get_meminfo");
/* Try new /proc/meminfo format first */
*swapdevs = 1;
if ((result[0].total = getentry("MemTotal:", buffer)) < 0 ||
(result[0].free = getentry("MemFree:", buffer)) < 0 ||
(result[0].shared = getentry("MemShared:", buffer)) < 0 ||
(result[0].buffers = getentry("Buffers:", buffer)) < 0 ||
(result[0].cache = getentry("Cached:", buffer)) < 0 ||
(result[1].total = getentry("SwapTotal:", buffer)) < 0 ||
(result[1].free = getentry("SwapFree:", buffer)) < 0) {
/* Fall back to old format */
bufptr = strchr( buffer, '\n' ) + 1;
sscanf( bufptr, "Mem: %d %*d %d %d %d",
&result[0].total,
&result[0].free,
&result[0].shared,
&result[0].cache );
result[0].buffers = -1;
for ( i = 1; i < MAX_SWAPFILES; i++ ) {
bufptr = strchr( bufptr, '\n' ) + 1;
if ( *bufptr == '\0' ||
(res = sscanf( bufptr, "Swap: %d %*d %d",
&result[i].total,
&result[i].free )) != 2 )
break;
}
*swapdevs = i - 1;
} else if (swaps_fd > 0) {
reread( swaps_fd, "get_meminfo");
bufptr = buffer;
for ( i = 1; i < MAX_SWAPFILES; i++ ) {
bufptr = strchr( bufptr, '\n' ) + 1;
if ( *bufptr == '\0' ||
(res = sscanf( bufptr, "%*s %*s %d %d",
&sw_size, &sw_used)) != 2 )
break;
result[i].total = sw_size;
result[i].free = sw_size - sw_used;
}
*swapdevs = i - 1;
}
}
double get_loadavg( void )
{
double load;
reread( loadavg_fd, "get_loadavg");
sscanf( buffer, "%lf", &load );
return load;
}
static struct load* last_load = NULL;
void get_load(struct load * result, int load_number)
{
struct load curr_load;
char *ptr = buffer;
int i;
reread( load_fd, "get_load" );
for ( i = 0; i < load_number; ++i )
ptr = strchr( ptr, '\n' ) + 1;
sscanf( ptr, "%*s %lu %lu %lu %lu\n", &curr_load.user,
&curr_load.nice, &curr_load.system, &curr_load.idle );
curr_load.total = curr_load.user + curr_load.nice + curr_load.system +
curr_load.idle;
result->total = curr_load.total - last_load[load_number].total;
result->user = curr_load.user - last_load[load_number].user;
result->nice = curr_load.nice - last_load[load_number].nice;
result->system = curr_load.system - last_load[load_number].system;
result->idle = curr_load.idle - last_load[load_number].idle;
last_load[load_number].total = curr_load.total;
last_load[load_number].user = curr_load.user;
last_load[load_number].nice = curr_load.nice;
last_load[load_number].system = curr_load.system;
last_load[load_number].idle = curr_load.idle;
}
int get_load_number( void )
{
int load_number = 0;
char *ptr = buffer;
reread( load_fd, "get_load_number" );
while( strncmp( ptr, "cpu", 3 ) == 0 ) {
load_number++;
ptr = strchr( ptr, '\n' ) + 1;
}
if ( load_number && last_load == NULL ) {
last_load = malloc(sizeof(*last_load) * load_number);
if ( last_load == NULL ) {
perror("get_load_number");
exit(1);
}
memset(last_load, 0, sizeof(*last_load) * load_number);
}
return load_number;
}
int sysinfo_init( void )
{
if ((meminfo_fd = open("/proc/meminfo",O_RDONLY)) < 0) {
perror("/proc/meminfo");
return 1;
}
if ((loadavg_fd = open("/proc/loadavg",O_RDONLY)) < 0) {
perror("/proc/loadavg");
return 1;
}
if ((load_fd = open("/proc/stat",O_RDONLY)) < 0) {
perror("/proc/stat");
return 1;
}
/* Failing here is not critical. We can get the info from meminfo. */
swaps_fd = open("/proc/swaps",O_RDONLY);
return 0;
}
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