PUTC(3S)            UNIX Programmer's Manual             PUTC(3S)

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

SYNOPSIS
     #include <stdio.h>

     int putc (c, stream)
     char c;
     FILE *stream;

     putchar (c)

     fputc (c, stream)
     FILE *stream;

     putw (w, stream)
     int w;
     FILE *stream;

HP-UX COMPATIBILITY
     Level:    HP-UX/RUN ONLY

     Origin:   System V

DESCRIPTION
     _P_u_t_c appends the character _c to the named output _s_t_r_e_a_m.  It
     returns the character written.

     _P_u_t_c_h_a_r(_c) is defined as _p_u_t_c(_c, _s_t_d_o_u_t).

     _F_p_u_t_c behaves like _p_u_t_c, but is a  genuine  function  rather
     than  a  macro;  it  may  therefore  be used as an argument.
     _F_p_u_t_c runs more slowly than _p_u_t_c, but takes less  space  per
     invocation.

     _P_u_t_w appends the word (i.e., int) _w to  the  output  _s_t_r_e_a_m.
     _P_u_t_w  neither  assumes  nor  causes special alignment in the
     file.

     The standard stream _s_t_d_o_u_t is normally  buffered.   However,
     if  the output refers to a terminal then the stream is line-
     buffered.  When a stream is line buffered, its  buffer  will
     be  flushed when a read(2) from the standard input is neces-
     sary, when a "\n" is written to stdout, when the  buffer  is
     full, or when fflush(stdout) is called.  This default may be
     changed by _s_e_t_b_u_f(3S).

     The standard stream _s_t_d_e_r_r is by default unbuffered uncondi-
     tionally,  but  use of _f_r_e_o_p_e_n (see _f_o_p_e_n(3S)) will cause it
     to become unbuffered; _s_e_t_b_u_f, again, will set the  state  to
     whatever  is  desired.   When an output stream is unbuffered
     information appears on the destination file or  terminal  as
     soon  as  written;  when  it is buffered many characters are
     saved up and written as a block.   See  also  _f_f_l_u_s_h  (under
     _f_c_l_o_s_e(3S)).

SEE ALSO
     ferror(3S),  fopen(3S),  fread(3S),  getc(3S),   printf(3S),
     puts(3S).

DIAGNOSTICS
     These functions return the constant EOF upon  error.   Since
     this  is a good integer, _f_e_r_r_o_r(3S) should be used to detect
     _p_u_t_w errors.

     Line buffering may cause confusion or malfunctioning of pro-
     grams  which use standard I/O routines but use _r_e_a_d(2) them-
     selves to read from standard input.  In cases where a  large
     amount  of computation is done after printing part of a line
     on an output terminal, it is necessary to  use  _f_f_l_u_s_h  (see
     _f_c_l_o_s_e(3S))  to  flush  the standard output before going off
     and computing so that the output will appear.

BUGS
     Because  it  is  implemented  as  a   macro,   _p_u_t_c   treats
     incorrectly a _s_t_r_e_a_m argument with side effects.  In partic-
     ular, putc(c, *f++); doesn't work sensibly.