How to check how many values will be put in an array

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C

numbers

Giving an array with size of N the C program will read a text file that contain numbers separeted by whitespace and will store them into the array. The N number is the first one in the file and is in different line than the other numbers.

Example of txt file:

10
9 8 5 4 585 2 14 5 9 8 

I want to make a check the exact time the array will save the number, if there are more numbers than the actual size of the array (eg 12 numbers) to exit.

I search all the web to find a solution but I couldn't.

I created a code that read the file with fscanf, but it slow down the program if should read more than 200.000 elements.

Here's the code anyway :

File *stream
stream = fopen("xxx_big.txt", "r");
	
	
	int t_size;
	
	 fscanf(stream, "%d", &t_size);
	int num = 0;           											
				int value = 0;    												

				while ( fscanf ( stream, "%d", &value) == 1)
				{ 																                                                        
				num++; 				                                                   
				}                     
				if ( num > t_size) 	
									
				{                     
				printf ( "too many integers\n");	
				getchar();			
				return 1;			
				}                     
				if ( num < t_size) 	
									
				{                     
				printf ( "not enough integers\n");	
				getchar();			
				return 1;			
				}      
	
			fclose(stream);

My program use getline() to read and split the numbers into a char and then using the following code will save the numbers into the array:

count = atoi(lines[0]); // First row has count 
	my_array = (int*)malloc(count * sizeof(int));
	if (my_array==NULL) {
		printf("Error allocating memory!\n"); //print an error message
		return 1; //return with failure
		getchar();
		}
	for (i = 0; i < count; ++i) {
		my_array[i] = atoi(lines[i + 1]);
	}

But as I mentioned I already put the numbers into a char so that check should be easy enough to create.

Here's all the code (without the fscanf check):

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int is_end(char* input) {
	return *input == 0;
}
 
int is_linebreak(char* input) {
	return *input == '\r' || *input == '\n' || *input == ' ';
}
 
char* eat_linebreaks(char* input) {
	while (is_linebreak(input))
		++input;
 
	return input;
}
 
size_t count_lines(char* input) {
	char* p = input;
	size_t rows = 1;
 
	if (is_end(p))
		return 0;
	
	while (!is_end(p)) {
		if (is_linebreak(p)) {
			++rows;
			p = eat_linebreaks(p);
		}
		else {
			++p;
		}
	}
	return rows;
}
 
/* split string by lines */
char** get_lines(char* input, size_t line_count) {
	char* p = input;
	char* from = input;
	size_t length = 0;
	size_t line = 0;
        int i;
	char** lines = (char**)malloc(line_count * sizeof(char*));
 
	do {
		if (is_end(p) || is_linebreak(p)) {
			lines[line] = (char*)malloc(length + 1);
			for (i = 0; i < length; ++i)
				lines[line][i] = *(from + i);
 
			lines[line][length] = 0;
			length = 0;
			++line;
			p = eat_linebreaks(p);
			from = p;
			
		}
		else {
			++length;
			++p;
		}
	} while (!is_end(p));
 
	// Copy the last line as well in case the input doesn't end in line-break
	lines[line] = (char*)malloc(length + 1);
	for (i = 0; i < length; ++i)
		lines[line][i] = *(from + i);
 
	lines[line][length] = 0;
	++line;
 

	return lines;
}
 
int main(int argc, char* argv[]) {

	char** lines;
	size_t size;
	size_t number_of_rows;
	int count;
	int* my_array;

 
	FILE *stream;
	char *contents;
	int fileSize = 0;
        int i;
 
	// Open file, find the size of it
	stream = fopen("xxx.txt", "r");
	
	
	if (stream == NULL) 
    {
        printf("Opening 'xxx.txt' file failed: %s\n",strerror(errno)); 
        getchar();               
        return 0;                
    } 
	else { 
	

	fseek(stream, 0L, SEEK_END);
	fileSize = ftell(stream);
	fseek(stream, 0L, SEEK_SET);
 
	// Allocate space for the entire file content
	contents = (char*)malloc(fileSize + 1);
 
	// Stream file into memory
	size = fread(contents, 1, fileSize, stream);
	contents[size] = 0; 
	fclose(stream);
 
	// Count rows in content
	number_of_rows = count_lines(contents);
 
	// Get array of char*, one for each line
	lines = get_lines(contents, number_of_rows);
	
	
	// Get the numbers out of the lines
	count = atoi(lines[0]); // First row has count
	my_array = (int*)malloc(count * sizeof(int));
	if (my_array==NULL) {
		printf("Error allocating memory!\n"); //print an error message
		return 1; //return with failure
		getchar();
		}
	for (i = 0; i < count; ++i) {
		my_array[i] = atoi(lines[i + 1]);
	}
	
	
	printf("All up and running! Array created! :D \n\n Array values: \n");
		for(i = 0; i < count; i++ )
		{
		printf(" %d : %d\n", i, my_array[i]);
		}
	
	
	free(my_array);
	fclose(stream);
	

	return 0;
	}
}