C - Buffersize conditional not breaking while loop - c

Question

UPDATE:
Okay, I'm going about this entirely the wrong way. The reason I'm not geting the result I want is because I'm reading from the terminal and awaiting an enter keypress before the program continues to execute. What I actually need to do is program a "screen" or x11 window to read real-time inputs. Therefore my question is now redundant. Thanks for everyone's suggestions.
Is there a better way to program this which would allow me to capture
keyPress time? And, why is the BUFFERSIZE conditional in the while loop not
breaking out of the loop?
#define BUFFERSIZE 100
int main(void) {
int terminalInput;
int keyPress = 0;
int inputArrayBuffer[BUFFERSIZE];
int bufferExceptionFlag = 0;
printf("\n\t\t\t->"); /* Prompt */
while((terminalInput = getchar()) != '\n' && keyPress < BUFFERSIZE) {
inputArrayBuffer[keyPress] = terminalInput;
++keyPress;
if (keyPress >= BUFFERSIZE) {
bufferExceptionFlag = 1;
}
}
return 0;
}

Answer 1

A few issues. For one, your inputArrayBuffer should be a char array, not an int array. Secondly, there are standard C libraries that include the functionality of what you want to do.
Question 1: "Is there a better way to program this which would allow me to capture keyPress time?"
Yes. For reading stdin until either a newline is encountered or a max length is encountered, the fgets function from stdio.h works nicely (although alternatives may exist). Something like,
fgets(inputArrayBuffer, BUFFERSIZE, stdin)
I understand you want to know the number of keys the user entered, not including the newline key. This is essentially the string length. An easier way to achieve this is to simply determine the length of the string entered by the user. Something like,
keyPress = strlen(inputArrayBuffer) - 1; // -1 because the newline '\n' is included in strlen if you use fgets
If you must capture a single character at a time, then the original code you proposed should work, just be certain to define inputArrayBuffer as char inputArrayBuffer[BUFFERSIZE];
Question 2: "And, why is the BUFFERSIZE conditional in the while loop not breaking out of the loop?"
It definitely should be breaking out of the loop. But don't confuse bufferExceptionFlag equaling the value 1 with signifying that keyPress < BUFFERSIZE didn't cause the loop to break. Clearly, when you ++keyPress inside the loop, if keyPress had the value of 99, it would then become 100, which would cause bufferExceptionFlag to be set. However, on the next loop iteration keyPress < BUFFERSIZE would be false and the loop would break.
Here is a more simple and appropriate solution in my opinion.
#include <stdio.h>
#include <string.h>
#define BUFFERSIZE 100
int main(void) {
char inputArrayBuffer[BUFFERSIZE];
unsigned long keyPress = 0;
printf("\n\t\t\t->"); /* Prompt */
fgets(inputArrayBuffer, BUFFERSIZE, stdin);
keyPress = strlen(inputArrayBuffer) - 1; // -1 because the newline '\n' is included in strlen if you use fgets
printf("User entered: %s\n", inputArrayBuffer);
printf("Input length: %lu\n", keyPress);
return 0;
}
Note that fgets includes the newline character on the string it reads. To remove this character you can do something like inputArrayBuffer[keyPress] = '\0';