Converting the text of a .txt file - c

Question

Objective: create a simple code that converts in a .txt file:
every 'I', 'E', 'A', 'S' and 'O' into '1', '3', '4', '5' and '0' respectively.
At first I made it very simply, but it couldn't handle multiple lines of text. So I tried to treat the phrases and lines as a matrix, but I still can't make it work. Here is the code:
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE *arquivo;
char frase[100][100];
int i = 0;
int j = 0;
//adress of the initial text file
arquivo = fopen("C:\\Users\\xand\\Desktop\\ex1.txt", "r");
//transfering every line of the file into a matrix
while (!feof(arquivo))
{
fgets(frase[100][i],100, arquivo);
i++;
}
fclose(arquivo);
//converting the letters to numbers
for(j = 0; j < 100; j++)
{
while(frase[i][j] != '\0')
{
if(frase[i][j] == 'i' || frase[i][j] == 'I')
{
frase[i][j] = '1';
}
if(frase[i][j] == 'e' || frase[i][j] == 'E')
{
frase[i][j] = '3';
}
if(frase[i][j] == 'a' || frase[i][j] == 'A')
{
frase[i][j] = '4';
}
if(frase[i][j] == 's' || frase[i][j] == 'S')
{
frase[i][j] = '5';
}
if(frase[i][j] == 'o' || frase[i][j] == 'O')
{
frase[i][j] = '0';
}
i++;
}
}
arquivo = fopen("ex1 criptografado.txt", "w");
//here is where I believe to be the problem
//It doesn't even create the new file. Im not sure if using matrix is the ideal solution to fprintf a multi-lined text to a file
for(j = 0; j < 100; j++)
{
i = 0;
while(frase[i][j] != '\0')
{
fprintf(arquivo, "%s", frase[i][j]);
i++;
}
fprintf(arquivo, "\n");
}
fclose(arquivo);
return 0;
}
The code compiles, but crashes as I try to run it. Can anyone help me with a solution for this?

Answer 1

#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE *f, *g;
int c;
if ((f = fopen("asdf.txt", "r")) == NULL) {
perror("fopen");
exit(1);
}
if ((g = fopen("asdf1.txt", "w")) == NULL) {
perror("fopen");
exit(1);
}
while ((c = fgetc(f)) != EOF) {
switch (c) {
case 'i':
case 'I':
fputc('1', g);
break;
case 'e':
case 'E':
fputc('3', g);
break;
case 'a':
case 'A':
fputc('4', g);
break;
case 's':
case 'S':
fputc('5', g);
break;
case 'o':
case 'O':
fputc('0', g);
break;
default:
fputc(c, g);
break;
}
}
fclose(f);
fclose(g);
return 0;
}
I've fixed your code. Mainly it was adding '\0' to all unused lines, not printing '\n' at the end of lines because it's put in the string by fgets, replacing frase[i][j] with frase[j][i], and the actual crash: fprintf(arquivo, "%c", frase[j][i]) instead of fprintf(arquivo, "%s", frase[i][j]).
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE *arquivo;
char frase[100][100];
int i = 0;
int j = 0;
//adress of the initial text file
arquivo = fopen("C:\\Users\\xand\\Desktop\\ex1.txt", "r");
//transfering every line of the file into a matrix
while (!feof(arquivo)) {
fgets(frase[i], 100, arquivo);
i++;
}
for (; i < 100; i++) {
frase[i][0] = '\0';
}
fclose(arquivo);
//converting the letters to numbers
for (j = 0; j < 100; j++) {
i = 0;
while (frase[j][i] != '\0') {
if (frase[j][i] == 'i' || frase[j][i] == 'I') {
frase[j][i] = '1';
}
if (frase[j][i] == 'e' || frase[j][i] == 'E') {
frase[j][i] = '3';
}
if (frase[j][i] == 'a' || frase[j][i] == 'A') {
frase[j][i] = '4';
}
if (frase[j][i] == 's' || frase[j][i] == 'S') {
frase[j][i] = '5';
}
if (frase[j][i] == 'o' || frase[j][i] == 'O') {
frase[j][i] = '0';
}
i++;
}
}
arquivo = fopen("ex1 criptografado.txt", "w");
for (j = 0; j < 100; j++) {
i = 0;
while (frase[j][i] != '\0') {
fprintf(arquivo, "%c", frase[j][i]);
i++;
}
}
// or simpler:
// for (j = 0; j < 100; j++)
// fprintf(arquivo, "%s", frase[j]);
fclose(arquivo);
return 0;
}

Answer 2

I think there's issue with Logic for using matrix.
You can take a chunk of string and then compare that for all characters - Change the character with Number if it's one of wanted characters (That you need to change), by writing character to stream - See fputc reference for details.
EDIT:
See the answer by #ctn - his code is good example.