Ignoring escape sequence in C - arrays

Question

I need to enter a matrix of size NxN of integers.
My idea is to enter it as a sequence of chars into char array and proceed working with it.
Matrix is given into stdin all at once.
The problem is to ignore escape characters (e.g. "\n") and enter all NxN integers as one string where integers will be separated with space.
Matrix itself is copied from txt file.
Input must end when Enter key is pressed.
//en axample of what I'm trying to reach
char buff[512];
gets(buff);
/*1 2 9 10 25
4 3 8 11 24
5 6 7 12 23
16 15 13 14 22
17 18 19 20 21*/
printf("%s", buff);
/*1 2 9 10 25
4 3 8 11 24
5 6 7 12 23
16 15 13 14 22
17 18 19 20 21/*
I tried using gets but it ended reading symbols when "\n" is reached.
Initial code looks like this:
int main(){
int size;
printf("enter size of matrix >> ");
scanf("%d",&size);
int matrix[size][size];
char allNumbers[size][512];
for (int i = 0; i < size; i++){
fgets(allNumbers[i], 511, stdin);
}
printf("%s", allNumbers[2]);
return 0;
}
input:1 2 9 10 25\n 4 3 8 11 24\n 5 6 7 12 23\n 16 15 13 14 22\n 17 18 19 20 21\0
output:
1 2 9 10 25

Answer 1

Consider using one char array for input.
Generally do not use both scanf and fgets.
This uses fgets to read a line with the size and sscanf to parse the integer from the line.
The same array is used to read the lines pasted from the file.
The loop continues until an empty line is read.
It may be necessary to hit enter a few times to exit the loop.
This does not parse the integers from the file. sscanf can be used to accomplish that as well. strtol is another parsing option.
#include <stdio.h>
#include <stdlib.h>
int main ( void) {
char input[512] = "";
int size = 0;
int row = 0;
int col = 0;
int offset = 0;
int used = 0;
printf ( "enter size of matrix >> ");
fflush ( stdout);
if ( ! fgets ( input, sizeof input, stdin)) {
fprintf ( stderr, "problem fgets\n");
return 1;
}
if ( 1 != sscanf ( input, "%d", &size)) {
fprintf ( stderr, "problem sscanf for size\n");
return 2;
}
int matrix[size][size];
for ( row = 0; row < size; ++row) {
for ( col = 0; col < size; ++col) {
matrix[row][col] = 0;
}
}
row = 0;
printf ( "enter matrix values >> ");
while ( fgets ( input, sizeof input, stdin)){
if ( '\n' == input[0]) {
break;
}
printf ( "\nrow %d %s", row, input);
offset = 0;
if ( row < size) {
// parse integers from input;
}
++row;
}
for ( row = 0; row < size; ++row) {
for ( col = 0; col < size; ++col) {
printf ( "%4d ", matrix[row][col]);
}
printf ( "\n");
}
return 0;
}