putchar

int putchar(int c);

What does this function do?

Writes 1 character to standard output (terminal or redirected to file).

When would you use this function?

1. When you need to write a simple character for formatting, such as a space, tab, newline, etc. to separate the output of other output functions like printf or fwrite.
2. To print a specific range of characters in a loop.

Where in your program would you call it?

Any place where you need a character to separate data or you are unsure of the value of a byte and need to debug something. This is especially true in loops to identify where bugs are.

Why is this function better or worse than alternatives?

putchar is simpler to use than printf and only requires one argument: the character number.

How can you use it?

Here is a complete program using putchar that writes all the printable characters to the terminal using a loop. It then prints a new line character with the escape sequence '\n'.

#include <stdio.h>

int main(int argc, char *argv[])
{
 int a=0x20,b=0x7F;

 while(a<b)
 {
  putchar(a);
  a+=1;
 }
 putchar('\n');
    
 return 0;
}

Compile and run

gcc -Wall -ansi -pedantic main.c -o main && ./main

Output

 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~