UCB stdio package

utzoo!decvax!ucbvax!dist2 utzoo!decvax!ucbvax!dist2
Sun Sep 27 04:03:27 AEST 1981


	As has been pointed out in this news group before, our version
of stdio does a form of ``line buffering'' on stdout.  The manual page
for putc.3s has been added to the man directory to document this
feature.  It should be added to all tapes made before 9/28/81 and is
included below.

			Carl

.TH PUTC 3S 
.SH NAME
putc, putchar, fputc, putw \- put character or word on a stream
.SH SYNOPSIS
.B #include <stdio.h>
.PP
.B int putc(c, stream)
.br
.B char c;
.br
.SM
.B FILE
.B *stream;
.PP
.B putchar(c)
.PP
.B fputc(c, stream)
.br
.SM
.B FILE
.B *stream;
.PP
.B putw(w, stream)
.br
.SM
.B FILE
.B *stream;
.SH DESCRIPTION
.I Putc
appends the character
.I c
to the named output
.IR stream .
It returns the character written.
.PP
.I Putchar(c)
is defined as 
.I "putc(c, stdout)."
.PP
.I Fputc
behaves like 
.I putc,
but is a genuine function rather than a macro.
It may be used to save on object text.
.PP
.I Putw
appends word 
(i.e.
.BR int )
.I w
to the output
.IR stream .
It returns the word written.
.I Putw
neither assumes nor causes special alignment in the file.
.PP
Unlike the original version of
.I stdio,
the standard stream
.I stdout
is always buffered;
this default may be changed by
.IR setbuf (3).
The standard stream
.I stderr
is by default unbuffered unconditionally,
but use of
.I freopen
(see
.IR fopen (3))
will cause it to become buffered;
.IR setbuf ,
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.
.I Fflush
(see 
.IR fclose (3))
may be used to force the block out early.
In addition,
all output streams associated with pipes or terminals are automatically
flushed before requesting input from a pipe or terminal.
.SH "SEE ALSO"
fopen(3), fclose(3), getc(3),
puts(3), printf(3),
fread(3)
.SH DIAGNOSTICS
These functions return the constant
.SM
.B EOF
upon error.
Since this is a good integer,
.IR  ferror (3)
should be used to detect 
.I putw
errors.
.SH BUGS
Because it is implemented as a macro,
.I putc
treats a
.I stream
argument with side effects improperly.
In particular
`putc(c, *f++);'
doesn't work sensibly.



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