putc(3S)             STANDARD I/O FUNCTIONS              putc(3S)



NAME
     putc, putchar, fputc, putw - put  character  or  word  on  a
     stream

SYNOPSIS
     #include <stdio.h>

     int putc (int c, FILE *stream);

     int putchar (int c);

     int fputc (int c, FILE *stream);

     int putw (int w, FILE *stream);

DESCRIPTION
     putc writes c (converted to an unsigned char) onto the  out-
     put  stream  [see  intro(3)]  at the position where the file
     pointer (if defined) is  pointing,  and  advances  the  file
     pointer appropriately.  If the file cannot support position-
     ing requests, or stream was opened  with  append  mode,  the
     character  is  appended to the output stream.  putchar(c) is
     defined as putc(c, stdout).  putc and putchar are macros.

     fputc behaves like putc, but is a  function  rather  than  a
     macro.   fputc runs more slowly than putc, but it takes less
     space per invocation and its name can be passed as an  argu-
     ment to a function.

     putw writes the word (i.e., integer) w to the output  stream
     (where the file pointer, if defined, is pointing).  The size
     of a word is the size of an integer and varies from  machine
     to  machine.  putw neither assumes nor causes special align-
     ment in the file.

SEE ALSO
     exit(2),   lseek(2),   write(2),   abort(3C),    fclose(3S),
     ferror(3S),   fopen(3S),  fread(3S),  printf(3S),  puts(3S),
     setbuf(3S), stdio(3S).

DIAGNOSTICS
     On success, these functions (with  the  exception  of  putw)
     each  return the value they have written.  putw returns fer-
     ror (stream).  On failure, they  return  the  constant  EOF.
     This  result  will occur, for example, if the file stream is
     not open for writing or if the output file cannot grow.

NOTES
     Because it is implemented  as  a  macro,  putc  evaluates  a
     stream  argument  more  than  once.   In particular, putc(c,
     *f++); doesn't work sensibly.  fputc should be used instead.
     Because  of  possible  differences  in  word length and byte



          Last change: C Programming Language Utilities         1

putc(3S)             STANDARD I/O FUNCTIONS              putc(3S)



     ordering, files written using  putw  are  machine-dependent,
     and may not be read using getw on a different processor.

     Functions exist for all the above defined  macros.   To  get
     the  function  form, the macro name must be undefined (e.g.,
     #undef putc).

















































          Last change: C Programming Language Utilities         2