cscd240_s12_lab11.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>

#include "cscd240fileutil.h"

char * prompt(char * prompt);
int * makeAndFillArray(FILE * fin, int * count);
double average(int count, int * array);

int main(int argc, char ** argv) {
	FILE * fin = NULL;
	char * fname;
	int * ara;
	int count = 0;
	int fdOut = -1;
	int fdIn = -1;
	double avg = 0.0;

	/*
	 * this is where it opens the file
	 */
	if(argc > 1) {
		fin = fopen(argv[1], "r");
	} else {
		fin = promptOpenInputFile();
	}	

	//Open the output file with a low-level call
	if(argc > 2) {
		fdOut = open(argv[2], O_WRONLY | O_CREAT, 0777);
	}

	if(fdOut == -1) {
		do {
			//HACK: Dynamically allocated strings for my comfort
			fname = prompt("Output filename> ");
		
			fdOut = open(fname, O_WRONLY | O_CREAT, 0777);	

			free(fname);
		} while (fdOut == -1);
	}

	//This somehow ignores the first integer in the file
	fscanf(fin, "%d", &count);

	//Fill the array so I can get the average
	ara = makeAndFillArray(fin, &count);

	avg = average(count, ara);

	printf("count: %i\n", count);

	//Write the average to the file in binary
	write(fdOut, &count, sizeof(int));

	//Close the output file
	assert(close(fdOut) == 0);
	fclose(fin);

	return 0;
}

char * prompt(char * prompt) {
	char temp[100];
	printf("%s", prompt);
	
	scanf("%s", temp);
	
	char * ret = calloc(strlen(temp), sizeof(char));

	strcpy(ret, temp);

	return ret;
}

int * makeAndFillArray(FILE * fin, int * count) {
	int total;

	fscanf(fin, "%i", &total);

	*count = total;

	//printf("%d\n", total);

	int * ara = (int *) malloc(*count * sizeof(int));
	
	//printf("%s\n", ara == NULL ? "YES" : "NO");

	int i, * ptr = ara;

	for(i = 0; i < *count; i++) {
		fscanf(fin, "%d", ptr);
		ptr++;
		//printf("%i\n", ara[i]);
	}

	//ara -= count-1;

	return ara;
}

double average(int count, int * array) {
	double val = 0.0;
	int i = 0, * ptr = array;

	for (i = 0; i < count; i++) {
		val = val + *ptr;
		ptr++;
	}
	
	val = val / count;
	
	return val;
}

cscd240_s12_lab11.pdf

cscd240fileutil.h

#ifndef CSCD240FILEUTIL_H

#define CSCD240FILEUTIL_H

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

FILE * openInputFile(char * fname);
FILE * promptOpenInputFile();

FILE * openOutputFile(char * fname);
FILE * promptOpenOutputFile();

#define READ "r"
#define WRITE "w"

#define MAXLINE 256
#define FNAMEMAX 100

#endif

input1.txt

7 7
5
32
55
4
15
22
35

input2.txt

2
3
4

lab11

libcscd240fileutil.a

Makefile

LIBS=libcscd240fileutil.a
CC=gcc
NAME=dodrills
ASSIGN=lab11
#pseudo-variable FLAGS

all:
	${CC} ${FLAGS} cscd240_s12_${ASSIGN}.c -o ${ASSIGN} ${LIBS}

debug:
	make FLAGS=-g

package:
	zip ${NAME}${ASSIGN}.zip lib/* 

output.txt

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