I have written a program, However I have discovered it has a memory leak

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Asked: June 15, 20262026-06-15T02:14:07+00:00 2026-06-15T02:14:07+00:00

I have written a program, However I have discovered it has a memory leak

0

I have written a program, However I have discovered it has a memory leak and after a few iterations it segfaults. I don’t understand where this memory leak is.

Here is the entire code snippet below. I’m aware there are conventional errors with the code, like the global allocation and making a buffer that is way larger than it needs to be. I just can’t see the source of the leak.

Thanks in advance.

#include <stdlib.h>
#include <stdio.h>

#define DATA 1000
#define TRUE 1
#define FALSE 0
const int16_t TIME = 600; // Time in seconds.
const int8_t DEBUG = 0;
// Globals Because I'm lazy!
long int cpua[5];
long int cpub[5];
long int mema[2];
long int nets[2];
long int netr[2];
int k=0;
char ch[150];
FILE *file_read;
char buffer[DATA];

void CPUread(void){
    file_read = popen("cat /proc/stat | grep \"cpu \"","r");
    fgets(buffer, DATA, file_read);
    sscanf(buffer,"%s %ld %ld %ld %ld %ld",&ch[0],&cpua[0],&cpua[1],&cpua[2],&cpua[3],&cpua[4]);

    // Time to read the network..
    file_read = popen("ifconfig | grep -m 1 \"RX bytes:\" | awk -F \"[^0-9]*\" '{ print $2 }'","r");
    fgets(buffer, DATA, file_read);
    sscanf(buffer,"%ld",&netr[0]);
    file_read = popen("ifconfig | grep -m 1 \"RX bytes:\" | awk -F \"[^0-9]*\" '{ print $5 }'","r");
    fgets(buffer, DATA, file_read);
    sscanf(buffer,"%ld",&nets[0]);

    // Time to read memory
    file_read = popen("cat /proc/meminfo | grep -m 1 \"MemFree\" | awk -F \"[^0-9]*\" '{ print $2 }'","r");
    fgets(buffer, DATA, file_read);
    sscanf(buffer,"%ld",&mema[0]);

    file_read = popen("cat /proc/meminfo | grep -m 1 \"MemTotal\" | awk -F \"[^0-9]*\" '{ print $2 }'","r");
    fgets(buffer, DATA, file_read);
    sscanf(buffer,"%ld",&mema[1]);
}


void main(void){
    FILE *file_write, *fp;
    int i;
    long int total=0, ptotal=0;
    int valid = FALSE;
    char charbuf[100];
    file_write=popen("echo -n \"/var/www/dir/`date +%Y-%b-%d`.csv\"","r");
    fgets(charbuf,100, file_write);
    while(1){
        // Open up the status file container and read from the system.
        if(valid == FALSE ){

            CPUread();
            // Need to make a new file here.... With Date code.
            fp=fopen(charbuf,"a");
            if ( fp == NULL){
                perror("Dummy Spit In initial File create!\n");
                exit(-1);
            }
            fprintf(fp,"CPU,IOwait,Memory,KB_up,KB_down\n");
            if(DEBUG) printf("CPU,IOwait,Memory,KB_up,KB_down\n");
            valid = TRUE;
            fclose(fp);
        }else{
            for(i=0;i<5;i++) cpub[i] = cpua[i];
            nets[1]=nets[0];
            netr[1]=netr[0];
            CPUread();

            total = 0;
            for(i=0;i<5;i++){
                cpub[i]=cpua[i]-cpub[i];
                total+=cpub[i];
            }
            // Time to find the CPU useage and IO waits...
            fp=fopen(charbuf,"a");
            if ( fp == NULL){
                perror("Dummy Spit Trying to open file\n");
                exit(-1);
            }
            fprintf(fp,"%0.2f,%0.2f,%0.2f,%ld,%ld\n",(((float)cpub[0])/total)*100,(((float)cpub[4]/total)*100),((((float)mema[1]-(float)mema[0])/(float)mema[1]))*100,(nets[0]-nets[1])/1024,(netr[0]-netr[1])/1024);
            if(DEBUG) printf("%0.2f,%0.2f,%0.2f,%ld,%ld\n",(((float)cpub[0])/total)*100,(((float)cpub[4]/total)*100),((((float)mema[1]-(float)mema[0])/(float)mema[1]))*100,(nets[0]-nets[1])/1024,(netr[0]-netr[1])/1024);
            fclose(fp);
        }
    sleep(TIME);
    }
}