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fputc(3C)		 Standard C Library Functions		     fputc(3C)

NAME
       fputc,  putc,  putc_unlocked,  putchar,	putchar_unlocked, putw - put a
       byte on a stream

SYNOPSIS
       #include	<stdio.h>

       int fputc(int c,	FILE *stream);

       int putc(int c, FILE *stream);

       int putc_unlocked(int c,	FILE *stream);

       int putchar(int c);

       int putchar_unlocked(int	c);

       int putw(int w, FILE *stream);

DESCRIPTION
       The fputc() function writes the byte specified by c  (converted	to  an
       unsigned	 char) to the output stream pointed to by stream, at the posi-
       tion indicated by the associated	file-position indicator	for the	stream
       (if  defined),  and  advances  the indicator appropriately. If the file
       cannot support positioning requests, or if the stream was  opened  with
       append mode, the	byte is	appended to the	output stream.

       The  st_ctime and st_mtime fields of the	file will be marked for	update
       between the successful execution	of fputc()  and	 the  next  successful
       completion  of a	call to	fflush(3C) or fclose(3C) on the	same stream or
       a call to exit(3C) or abort(3C).

       The putc() routine behaves like fputc(),	except that it is  implemented
       as a macro. It runs faster than fputc(),	but it takes up	more space per
       invocation and its name cannot be passed	as an argument to  a  function
       call.

       The  call  putchar(c)  is  equivalent to	putc(c,	stdout). The putchar()
       routine is implemented as a macro.

       The putc_unlocked() and putchar_unlocked()  routines  are  variants  of
       putc() and putchar(), respectively, that	do not lock the	stream.	 It is
       the caller's responsibility to acquire the stream lock  before  calling
       these routines and releasing the	lock afterwards; see flockfile(3C) and
       stdio(3C). These	routines are implemented as macros.

       The putw() function writes the word (that is, type int) w to the	output
       stream (at the position at which	the file offset, if defined, is	point-
       ing). The size of a word	is the size of a type int and varies from  ma-
       chine  to machine.  The putw() function neither assumes nor causes spe-
       cial alignment in the file.

       The st_ctime and	st_mtime fields	of the file will be marked for	update
       between the successful execution	of putw() and the next successful com-
       pletion of a call to fflush(3C) or fclose(3C) on	the same stream	 or  a
       call to exit(3C)	or abort(3C).

RETURN VALUES
       Upon   successful   completion,	 fputc(),   putc(),   putc_unlocked(),
       putchar(), and putchar_unlocked() return	the value  that	 was  written.
       Otherwise,  these  functions  return  EOF,  the error indicator for the
       stream is set, and errno	is set to indicate the error.

       Upon successful completion, putw() returns 0. Otherwise,	it  returns  a
       non-zero	value, sets the	error indicator	for the	associated stream, and
       sets errno to indicate the error.

       An unsuccessful completion will occur, for example, if the file associ-
       ated  with  stream is not open for writing or if	the output file	cannot
       grow.

ERRORS
       The fputc(), putc(),  putc_unlocked(),  putchar(),  putchar_unlocked(),
       and  putw()  functions  will fail if either the stream is unbuffered or
       the stream's buffer needs to be flushed,	and:

       EAGAIN
	     The O_NONBLOCK flag is set	for  the  file	descriptor  underlying
	     stream and	the process would be delayed in	the write operation.

       EBADF The  file	descriptor  underlying	stream is not a	valid file de-
	     scriptor open for writing.

       EFBIG An	attempt	was made to write to a file that exceeds  the  maximum
	     file size	or the process'	file size limit.

       EFBIG The file is a regular file	and an attempt was made	to write at or
	     beyond the	offset maximum.

       EINTR The write operation was terminated	due to the receipt of  a  sig-
	     nal, and no data was transferred.

       EIO   A physical	I/O error has occurred,	or  the	process	is a member of
	     a background process group	attempting to write to its controlling
	     terminal,	TOSTOP	is  set,  the  process is neither ignoring nor
	     blocking SIGTTOU and the process group  of	 the  process  is  or-
	     phaned.  This error may also be returned under implementation-de-
	     pendent conditions.

       ENOSPC
	     There was no free space remaining on the  device  containing  the
	     file.

       EPIPE An	 attempt  is  made to write to a pipe or FIFO that is not open
	     for reading by any	process. A SIGPIPE signal will also be sent to
	     the process.

       The  fputc(),  putc(),  putc_unlocked(),	putchar(), putchar_unlocked(),
       and putw() functions may	fail if:

       ENOMEM
	     Insufficient storage space	is available.

       ENXIO A request was made	of a non-existent device, or the  request  was
	     outside the capabilities of the device.

USAGE
       Functions   exist  for  the  putc(),  putc_unlocked(),  putchar(),  and
       putchar_unlocked() macros. To get the function  form,  the  macro  name
       must be undefined (for example, #undef putc).

       When  the macro forms are used, putc() and putc_unlocked() evaluate the
       stream argument more than once. In particular, putc(c, *f++); does  not
       work sensibly.  The fputc() function should be used instead when	evalu-
       ating the stream	argument has side effects.

       Because of possible differences in word length and byte ordering, files
       written	using putw() are implementation-dependent, and possibly	cannot
       be read using getw(3C) by a different application or by the same	appli-
       cation running in a different environment.

       The  putw() function is inherently byte stream oriented and is not ten-
       able in the context of either multibyte character streams or wide-char-
       acter streams. Application programmers are encouraged to	use one	of the
       character-based output functions	instead.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |See NOTES	below.		   |
       +-----------------------------+-----------------------------+

SEE ALSO
       getrlimit(2),  ulimit(2)	 write(2),  intro(3),	abort(3C),   exit(3C),
       fclose(3C),   ferror(3C),   fflush(3C),	 flockfile(3C),	  fopen(3UCB),
       printf(3C), putc(3C), puts(3C), setbuf(3C), stdio(3C), attributes(5)

NOTES
       The fputc(), putc(), putchar(), and putw() routines are MT-Safe in mul-
       tithreaded  applications.   The	putc_unlocked()	and putchar_unlocked()
       routines	are unsafe in multithreaded applications.

SunOS 5.9			  23 Jul 2001			     fputc(3C)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | USAGE | ATTRIBUTES | SEE ALSO | NOTES

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