Assignment 1 Submission

mm.c

@@ -0,0 +1,94 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#define debug 0
+
+// Comparison function for qsort()
+int numcmp (const void *a, const void *b) {
+    int x = *((int*) a);
+    int y = *((int*) b);
+    if (x > y) return 1;
+    if (x < y) return -1;
+    return 0;
+}
+int median (int length, int *pt)
+{
+	int median = 0;
+	if(length % 2 == 0)
+	{
+		median = (pt[length/2] + pt[length/2-1])/2;
+	}
+	else 
+		median = pt[(length-1)/2];
+	return median;
+}
+int mean (int length, int *pt)
+{
+	int i;
+	int sum = 0;
+	for ( i = 0; i < length; i++)
+	{
+		sum = sum + pt[i];
+	}
+	return(sum/length);
+}
+
+int main(int argc, char *argv[]) {
+
+    int i, length, *pt;
+
+    // Check for proper usage
+    if (argc < 2) {
+        fprintf(stderr, "%s: Aborting, not enough arguments.\n", argv[0]);
+        return (-1);
+    }
+
+    // Determine amount of numbers from argc
+    length = argc - 1;
+#if debug
+    fprintf(stderr, "%s: DEBUG: %d numbers were passed.\n", argv[0], length);
+#endif
+
+    // Allocate memory for array of number (and error check)
+    if ((pt = malloc(length * sizeof(int))) == NULL) {
+        fprintf(stderr, "%s: Could not allocate memory.\n", argv[0]);
+    }
+
+    // Read numbers into array
+    for (i = 0; i < length; i++) {
+        pt[i] = (int) strtol(argv[i+1], NULL, 10);
+    }
+    qsort(pt, length, sizeof(int), numcmp);
+
+    // Print out numbers
+    fprintf(stdout, "%s: Sorted output is: \n", argv[0]);
+    for (i=0; i<length; i++) {
+        fprintf(stdout, "%d ", pt[i]);
+    }
+    printf("\n");
+    int rc = fork();	//calling the fork method
+    if(rc < 0) // fork failed
+    {
+	fprintf(stderr, "fork failed!\n");
+	exit(1);
+    }
+    else if(rc == 0)	//child call median()
+    {
+	int medianValue = median(length, pt);
+	//Child printing the results of median.
+    	fprintf(stdout, "\nThe median of the numbers is %d.\nThis completes the task #3 of the Assignment.\n", medianValue);
+	fprintf(stdout, "\nThe child has finished now. Process id: %d\n\n", (int) getpid());
+    }
+    else
+    {			//Parent calling mean()
+	int wc = wait(NULL);
+    	int value = mean(length, pt);
+	//Parent printing the results of mean.
+	fprintf(stdout, "Process id %d, (wc:%d)", (int) getpid(), wc);
+    	fprintf(stdout, "\nThe mean of the numbers is %d.\nThis completes the task #2 of the Assignment.\n", value );
+
+    }
+    return 0;
+}