How to use getchar() and redirect to input textfile in ASCI C programming.

Hello, underneath is the code I did and it works where it counts and prints out upper and lower case of each letter. For instance, "Hello World", there are H=1, e = 1, l = 3..etc. However, my professor is asking to use getchar() and use an input text file to redirect it. How would i do that on my code? Thank you for the help.

#include #include int main() { char string[100]; int c = 0, Lcase[26] = {0}, x; int Ucase[26] = {0}; printf("Enter a string "); gets(string); while (string[c] != '\0') { if (string[c] >= 'a' && string[c] <= 'z') { x = string[c] - 'a'; Lcase[x]++; } if( string[c] >= 'A' && string[c] <= 'Z') { x = string[c] - 'A'; Ucase[x]++; } c++; } for (c = 0; c < 26; c++) { printf("%c occurs %d times in the string. ", c + 'a', Lcase[c]); } for (c = 0; c < 26; c++) { printf("%c occurs %d times in the string. ", c + 'A', Ucase[c]); } return 0;

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