trying to write integers into file genreates random characters in C language - c

Question

I'm trying to make a random input.txt file generator in C language but I keep getting random characters in the output file. I tried using both putw() and fwrite() but I get the same result.
for(int i = 0; i < 100; i++){
ran_numb = rand()%(ram_size-1);
// printf("%d", ran_numb);
// int err = putw(ran_numb, fp);
fwrite(&ran_numb, sizeof(int), 1, fp);
fputc('\n', fp);
}
output file:
~
ô
u
?
{
ø
È
Õ
å
×
¡
full code:
#include <stdio.h>
#include <string.h>
int main (int argc, char* argv){
generate_input_file(2048);
}
void generate_input_file(int ram_size){
int ran_numb = 0;
FILE *fp = fopen("input.txt", "w");;
if(fp == NULL){
printf("can't open file!");
}
for(int i = 0; i < 100; i++){
ran_numb = rand()%(ram_size-1);
// printf("%d", ran_numb);
// int err = putw(ran_numb, fp);
fwrite(&ran_numb, sizeof(int), 1, fp);
fputc('\n', fp);
}
}

Answer 1

After the help of the comments, this is the final program:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
#include "simulator.h"
int main (int argc, char* argv){
generate_input_file(2048);
}
void Gen_Input_File(int ram_size){
int ran_numb = 0;
const char filename[] = "input.txt"
FILE *fp = fopen(filename, "w");;
if(fp == NULL){
fprintf(stderr, "Failed to open file '%s' for writing: %s\n", filename, strerror(errno));
exit(EXIT_FAILURE);
}
srand(time(NULL));
for(int i = 0; i < 10000; i++){
ran_numb = rand()%(ram_size-1);
fprintf(fp, "%d\n", ran_numb);
}
}
I've added the missing headers to stop warnings.