C’de Processler ve IPC

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
 
#define LINE 255
int main() {
 
    /* Acilis yazilari BASLANGICI */
    printf("Umut BENZER\n");
    printf("05-06-7670\n");
    printf("Ege Universitesi Bilgisayar Muhendisligi 3. Sinif\n");
    printf("http://www.ubenzer.com\n");
    printf("Processes\n\n");
    /* Acilis yazilari SONU */
 
    int m;
    int n;
    int k;
 
    int pid;
    pid = fork();
 
    if (pid == 0) {
        /* B süreci */
        FILE *fp;
        if((fp=fopen("input.txt","r")) == NULL) {
            printf ("Dosya acilamadi.");
            exit(-1);
        }
 
        fscanf(fp,"%d %d %d",&m, &n, &k);
 
        int matrisA[m][n];
        int matrisB[n][k];
        int matrisC[m][k];
 
        int i;
        int j;
 
        for(i=0;i<m;i++) {
             for(j=0;j<k;j++) {
                matrisC[i][j] = 0;
            }
        }
 
        /* A MATRISINI OKU */
        for(i=0;i<m;i++) {
            for(j=0;j<n;j++) {
                fscanf(fp,"%d",&matrisA[i][j]);
            }
        }
 
        /* B MATRISINI OKU */
        for(i=0;i<n;i++) {
            for(j=0;j<k;j++) {
                fscanf(fp,"%d",&matrisB[i][j]);
            }
        }
 
        fclose(fp);
 
        /* EKRANA MATRISLERI YAZDIR */
        printf("Matris A:\n");
        for(i=0;i<m;i++) {
            for(j=0;j<n;j++) {
                printf("%d\t", matrisA[i][j]);
            }
            printf("\n");
        }
 
        printf("\nMatris B:\n");
        for(i=0;i<n;i++) {
            for(j=0;j<k;j++) {
                printf("%d\t", matrisB[i][j]);
            }
            printf("\n");
        }
 
        int pidler[m];
        int pipeler[i][2];
        for(i=0;i<m;i++) {
 
            if(pipe(pipeler[i]) < 0) fprintf(stderr, "Program coker. %d\n", errno);
            pidler[i] = fork();
            if (pidler[i] == 0) {
                close(pipeler[i][0]); /* OKuma ucunu kapat */
                int ic1,ic2;
                int temp = 0;
                for(ic1=0; ic1<k; ic1++) {
                    for(ic2=0; ic2<n; ic2++)  {
                        temp += matrisA[i][ic2] * matrisB[ic2][ic1];
                    }
 
                    /* integer to char array dönüşümü */
                    char array[LINE] = {0};
                    sprintf(array, "%d\n", temp);
                    write(pipeler[i][1],array,LINE);
                    temp = 0;
                }
 
                exit(0);
 
            } else if(pidler[i] > 0) {
                close(pipeler[i][1]); /* Yazma ucunu kapat. */
 
            } else {
                fprintf(stderr, "Fork yapamadim. %d\n", errno);
                exit(EXIT_FAILURE);
            }
        }
        for(i=0;i<m;i++) {
            wait(pidler[i]);
        }
 
        char veribuf[LINE];
        for(i=0;i<m;i++) {
            for(j=0;j<n;j++) {
                read(pipeler[i][0],veribuf,LINE);
                matrisC[i][j] = atoi(veribuf);
            }
        }
 
        printf("\nMatris C:\n");
        for(i=0;i<m;i++) {
            for(j=0;j<k;j++) {
                printf("%d\t", matrisC[i][j]);
            }
            printf("\n");
        }
        exit(0);
 
    } else if (pid > 0) {
        wait();
    } else {
        fprintf(stderr, "Fork yapamadim. %d\n", errno);
        exit(EXIT_FAILURE);
    }
}