Putchar

From Wikipedia, the free encyclopedia

The correct title of this article is putchar. The initial letter is shown capitalized due to technical restrictions.

putchar is a function in C programming language that writes a single character to the standard output stream, stdout. Its prototype is as follows:

int putchar (int character)

The character to be printed is fed into the function as an argument, and if the writing is successful, the argument character is returned. Otherwise, end-of-file is returned.

The putchar function is specified in the C standard library header file stdio.h.

[edit] Sample usage

The following program uses getchar to read characters into an array and print them out using the putchar function after an end-of-file character is found.

 #include <stdio.h>

 int main(void)
 {
   char str[1000];
   int ch, n = 0;
  
   while ((ch = getchar()) != EOF && n < 1000)
     str[n++] = ch;
           
   for (int i = 0; i < n; ++i)
     putchar(str[i]);

   putchar('\n'); /* trailing '\n' needed in Standard C */
        
   return 0;
 }

The program specifies the reading length's maximum value at 1000 characters. It will stop reading either after reading 1000 characters or after reading in an end-of-file indicatorm, whichever comes first.