C program complies but screen on console remains black - c

Question

I was writing a C program that would read and merge 3 files together (program not complete yet), however, as I was testing I realized the program compiles but the screen on the console remains blank!
Any help is appreciated, especially why is it blank?
#include <stdio.h>
#include <stdlib.h>
int main()
{
printf("test");
//open three files for merging
FILE *fp1 = fopen("american0.txt","r");
FILE *fp2 = fopen("american1.txt","r");
FILE *fp3 = fopen("american2.txt","r");
printf("test");
//open file to store the result
FILE *fpm = fopen("words.txt", "w");
//creating an array to save the files data
char c;
char mergedFile[50];
//checking to make sure files are being read
if(fp1 == NULL && fp2 == NULL && fp3 == NULL && fpm == NULL)
{
printf("Could not open one or all of the files.\n");
printf("Exiting program!");
exit(0);
}
printf("test");
//initializing counter values
//inserting data from file into an array
while ((c = fgetc(fp1)) != EOF)
{
fputc(c, mergedFile);
}
while ((c = fgetc(fp2)) != EOF)
{
fputc(c, mergedFile);
}
while ((c = fgetc(fp3)) != EOF)
{
fputc(c, mergedFile);
}
printf("%s",mergedFile[0]);
printf("test");
return 0;
}

Answer 1

Error --> fputc requires a file pointer as it's second argument rather than an array: int fputc ( int character, FILE * stream );
Points to be taken care of:
The size of array should be large enough to contain all the data from these files.
Take care of the format specifier and what it requires in a char array.
What if size of array is less than total size of all files? - Error handling
What if files to be read/written into are in some other directory?
Here is a minimal corrected version:
#include <stdio.h>
#include <stdlib.h>
#define MAX 1000 //ADDED NEW
int main()
{
//open three files for merging
FILE *fp1 = fopen("american0.txt","r");
FILE *fp2 = fopen("american1.txt","r");
FILE *fp3 = fopen("american2.txt","r");
//open file to store the result
FILE *fpm = fopen("words.txt", "w");
//creating an array to save the files data
int c;
int i=0;
char mergedFile[MAX]={0}; //MODIFIED & INITIALIZED
//checking to make sure files are being read
if(fp1 == NULL && fp2 == NULL && fp3 == NULL && fpm == NULL)
{
printf("Could not open one or all of the files.\n");
printf("Exiting program!");
exit(0);
}
//initializing counter values
//inserting data from file into an array
while (((c = fgetc(fp1)) != EOF)&&(i<MAX)) //MODIFIED
{
mergedFile[i++]=c; //MODIFIED
}
while (((c = fgetc(fp2)) != EOF)&&(i<MAX)) //MODIFIED
{
mergedFile[i++]=c; //MODIFIED
}
while (((c = fgetc(fp3)) != EOF)&&(i<MAX)) //MODIFIED
{
mergedFile[i++]=c; //MODIFIED
}
printf("%s",mergedFile); //MODIFIED
return 0;
}