Two identical loops but the second one continues infinitely - c

Question

Expected output of program is to print a border of a specified character around a sentence input by the user.
//program: border.c
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
int argu = argc - 1;
if(argu < 1){
printf("usage: border arguments are the text to border.\n");
}
else{
printf("Enter the character for the border: ");
char in = getchar();//get the character input by user
int size;
for(int i = 1; i <= argu; i++){// gets the count of the characters in the string
size += strlen(argv[i]);
size += 1; //to compensate for spaces
}
printf("%d", size);
printf("\n");
size += 2;
for( int a = 0; a <= size ; a++){
printf("%c", in); // prints the first border line
}
printf("\n");
printf("%c%*c\n", in, size, in);//prints second line of border line.
printf("%c", in);
printf(" ");
for( int i = 1; i <= argu; i++){//prints the sentence that was typed.
printf("%s " , argv[i]);
}
printf("%c", in);
printf("\n");
printf("%c%*c\n", in, size, in);// same as the second line.
printf("%d", size);
for( int b = 0; b <= size ; b++){ //causing the infinite loop
printf("%c", in);
}
printf("\n");
}
return 0;
My first loop works fine:
for( int a = 0; a <= size ; a++){
printf("%c", in); // prints the first border line
}
but when I included the second one, which is identical, it caused my program to continue infinately.
for( int b = 0; b <= size ; b++){
printf("%c", in);
}

Answer 1

As was mentioned in the comments, you never initialize size which means it has some random value. So you end up printing a number of border characters equal to that random value plus the intended length of the border.
If you do this:
int size = 0;
That will solve the problem. Sample input/output:
[dbush#db-centos tmp]$ ./x1 test text
Enter the character for the border: x
10
xxxxxxxxxxxxx
x x
x test text x
x x
12xxxxxxxxxxxxx
So now we see that there's a number stuck at the bottom border. That's because you're printing size before the bottom border, so you should move that printf to after the loop to print that border.
So change this:
printf("%c%*c\n", in, size, in);// same as the second line.
printf("%d", size);
for( int b = 0; b <= size ; b++){ //causing the infinite loop
printf("%c", in);
}
To this:
printf("%c%*c\n", in, size, in);// same as the second line.
for( int b = 0; b <= size ; b++){ //causing the infinite loop
printf("%c", in);
}
printf("%d", size); // this line moved down