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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#include "node.h"
#include "sysinfo.h"
/*
* This code is heavily modified from the procps package.
*/
#define UPTIME_FILE "/proc/uptime"
#define LOADAVG_FILE "/proc/loadavg"
#define MEMINFO_FILE "/proc/meminfo"
static char buf[4096];
/* This macro opens FILE only if necessary and seeks to 0 so that successive
calls to the functions are more efficient. It also reads the current
contents of the file into the global buf.
*/
#define FILE_TO_BUF(FILE) { \
static int n, fd = -1; \
if (fd == -1 && (fd = open(FILE, O_RDONLY)) == -1) { \
node_perror(FILE, errno); \
close(fd); \
return 0; \
} \
lseek(fd, 0L, SEEK_SET); \
if ((n = read(fd, buf, sizeof buf - 1)) < 0) { \
node_perror(FILE, errno); \
close(fd); \
fd = -1; \
return 0; \
} \
buf[n] = '\0'; \
}
#define SET_IF_DESIRED(x,y) if (x) *(x) = (y) /* evals 'x' twice */
int uptime(double *uptime_secs, double *idle_secs)
{
double up=0, idle=0;
FILE_TO_BUF(UPTIME_FILE)
if (sscanf(buf, "%lf %lf", &up, &idle) < 2) {
node_msg("Bad data in " UPTIME_FILE );
return 0;
}
SET_IF_DESIRED(uptime_secs, up);
SET_IF_DESIRED(idle_secs, idle);
return up; /* assume never be zero seconds in practice */
}
int loadavg(double *av1, double *av5, double *av15)
{
double avg_1=0, avg_5=0, avg_15=0;
FILE_TO_BUF(LOADAVG_FILE)
if (sscanf(buf, "%lf %lf %lf", &avg_1, &avg_5, &avg_15) < 3) {
node_msg("Bad data in " LOADAVG_FILE );
return 0;
}
SET_IF_DESIRED(av1, avg_1);
SET_IF_DESIRED(av5, avg_5);
SET_IF_DESIRED(av15, avg_15);
return 1;
}
int load_meminfo(void)
{
FILE_TO_BUF(MEMINFO_FILE)
return 1;
}
int meminfo(const char *s)
{
char *cp;
int len;
len = strlen(s);
cp = buf;
while (1) {
if (strncasecmp(cp, s, len) == 0) {
cp += len;
if (*cp == ':')
return atoi(++cp);
}
if ((cp = strchr(cp, '\n')) == NULL)
break;
cp++;
}
return -1;
}
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