Question

Why this output gets incorrect result.

This is my task.

Write a C program that sends the following 3 lines of text data to the printer:
- Name and surname of the student in large font,
- Faculty number of the student in condensed font,
- Date in DD.MM.YYYY type with normal font.

So here my code:

#include

#include

#include

#include

void main(){

char row1[]={0x1B,0x13,'K','o','n','s','t','a','n','t','i','n',0x0d,0x0a};

char type[]={0x1b,0x14,0x1b,0x14};

char row2[]="20621321";

char row3[]="21-03-2023";

for(int i=0;i<30;i++){

printf("%c",row1[i]);

printf("\\);

}

for(i=2;i<2;i++){

printf("%c",type[i]);

}

for(i=0;i<20;i++){

printf("%c",row2[i]);

printf("\\);

}

for(i=2;i<4;i++){

printf("%c",type[i]);

}

for(i=0;i<20;i++){

printf("%c",row3[i]);

printf("\\);

getch();

}

void print(char alphabet){

union REGS reg;

reg.h.ah=0x00;

reg.h.al=alphabet;

pregs.x.dx=0;

int86(0x17,®,®);

}

void end(){

union REGS reg;

reg.h.ah=0x00;

reg.h.al=0x0A;

reg.x.dx=0;

int86(0x17,®,®);

}

That is my output result.

Answer 1

The provided C program contains several errors that may lead to incorrect results. Specifically, there are syntax errors in the `printf` statements, a missing closing brace for the `main` function, and a potential issue with the loop conditions. To fix these issues and achieve the desired output, the code needs careful debugging and corrections.

Step-by-step explanation:

Firstly, the `printf` statements have syntax errors, with missing double quotes and closing parentheses. For instance, in the lines `printf("%c",row1[i]);` and `printf("\\);`, the closing double quote and parenthesis are misplaced. Correcting this by adding the missing double quotes and fixing the parentheses will ensure proper printing of the text data.

Secondly, the loop conditions seem problematic. For example, in the loop `for(i=2;i<2;i++)`, the condition `i<2` will never be satisfied, leading to the loop not executing. This loop is intended to print the font type, and correcting the condition to `i<4` will ensure it runs correctly.

Lastly, the `getch()` function is placed inside a loop that prints the date. This might cause the program to wait for user input after printing each character of the date, which is not the desired behavior. Placing `getch()` outside the loop for printing the date will resolve this issue.

By addressing these issues, the program should be able to send the specified text data to the printer as intended. Debugging syntax errors, fixing loop conditions, and adjusting the placement of functions are crucial steps to ensure the proper execution of the C program and achieve the desired output.