Program not running because of "underscore" - c

Question

I made a program to print an ASCII table up to a certain range (like ASCII from 0 to 104).
#include <stdio.h>
int main(void)
{
int n;
printf("\n\nthis program will print list of ASCII values for your computer enter the upper limit for the range - ");
scanf("%d", &n);
printf("\nDECIMAL\tCHARACTER");
for (int i = 0; i <= n; i++)
{
printf("\n %d | %c", i, i);
// printf("\n-------------");
printf("_"); //when i include this "undescore" it causes problems, the code stops at 27th ASCII character and gets stuck.
}
return 0;
}
The 27 decimal corresponds to ASCII SYSTEM CODE - [ESCAPE].
None of the following works, and the code stops at the 27th ASCII character:
printf("__"); //double or multiple underscore does not work.
printf("\n_"); //this doesnt work either.
printf("//_"); //somehow this works.
If I remove that printf("_"); part then the code does not stop at 27 and runs smoothly, the code only stops when I use the underscore (_) character.
If I use a different character (-, *, etc), it runs smoothly.
What can the problem be? Could it be something related to macros?
Edit-
when I replaced 'printf("_");' with 'printf("n");' thinking it would perform the same as '\n' some weird language popped up and the language of the terminal changed.
when '_' is replaced by 'n'

Answer 1

Your terminal support ANSI escape sequences which means it does something with ESC _: Application Program Command. In general, if your printing it, you probably want to make sure it shows up so I am using an alternative format here for non-printable characters:
#include <ctype.h>
#include <stdio.h>
int main(void) {
printf("\n\nthis program will print list of ASCII values for your computer enter the upper limit for the range - ");
int n;
scanf("%d", &n);
printf("\nDECIMAL\tCHARACTER");
for (int i = 0; i <= n; i++) {
if(isprint(i))
printf("\n %d | %c", i, i);
else
printf("\n %d | 0x%x", i, i);
printf("_");
}
}
Here is a sample output:
this program will print list of ASCII values for your computer enter the upper limit for the range - 38
DECIMAL CHARACTER
0 | 0x0_
1 | 0x1_
2 | 0x2_
3 | 0x3_
4 | 0x4_
5 | 0x5_
6 | 0x6_
7 | 0x7_
8 | 0x8_
9 | 0x9_
10 | 0xa_
11 | 0xb_
12 | 0xc_
13 | 0xd_
14 | 0xe_
15 | 0xf_
16 | 0x10_
17 | 0x11_
18 | 0x12_
19 | 0x13_
20 | 0x14_
21 | 0x15_
22 | 0x16_
23 | 0x17_
24 | 0x18_
25 | 0x19_
26 | 0x1a_
27 | 0x1b_
28 | 0x1c_
29 | 0x1d_
30 | 0x1e_
31 | 0x1f_
32 | _
33 | !_
34 | "_
35 | #_
36 | $_
37 | %_