putchar

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< clrm; | io
File input/output
Functions
File access
Direct input/output
Unformatted input/output
(until C11)(since C11)
putchar
(C95)(C95)
(C95)
(C95)(C95)
(C95)
(C95)
Formatted input
Formatted output
File positioning
Error handling
Operations on files
Defined in header <stdio.h>
int putchar( int ch );

Writes a character ch to stdout. Internally, the character is converted to unsigned char just before being written.

Equivalent to putc(ch, stdout).

Parameters

ch - character to be written

Return value

On success, returns the written character.

On failure, returns EOF and sets the error indicator (see ferror()) on stdout.

Example

putchar with error checking

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    int ret_code = 0;
    for (char c = 'a'; (ret_code != EOF) && (c != 'z'); c++)
        ret_code = putchar(c);

    /* Test whether EOF was reached. */
    if (ret_code == EOF)
       if (ferror(stdout)) 
       {
          fprintf(stderr,"putchar() failed in file%s at line #%d\n", __FILE__,__LINE__-6);
          perror("putchar()");
          exit(EXIT_FAILURE);
       }
    putchar('\n');

    // putchar return value is not equal to the argument
    int r = 0x1070;
    printf("\n0x%x\n", r);
    r = putchar(r);
    printf("\n0x%x\n", r);
}

Output:

abcdefghijklmnopqrstuvwxy

0x1070
p
0x70

References

  • C11 standard (ISO/IEC 9899:2011):
  • 7.21.7.8 The putchar function (p: 333)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.19.7.9 The putchar function (p: 299)
  • C89/C90 standard (ISO/IEC 9899:1990):
  • 4.9.7.9 The putchar function

See also

writes a character to a file stream
(function)