putc.3s

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3S 代码 · 共 76 行

.\" SCCSID: @(#)putc.3s	8.1	9/11/90
.TH putc 3s 
.SH Name
putc, putchar, fputc, putw \- put character or word on a stream
.SH Syntax
.B #include <stdio.h>
.PP
.B int putc\^(\fIc, stream\fP)
.nf
.B char \fIc\fP;
.B FILE \fI*stream\fP;

.B putchar\^(\fIc\fP)

.B fputc\^(\fIc, stream\fP)
.B FILE \fI*stream\fP

.B putw\^(\fIw, stream\fP)
.B FILE \fI*stream\fP;
.fi
.SH Description
.NXR "putc subroutine" 
.NXR "standard IO" "subroutines for"
.NXR "putchar subroutine"
.NXR "putw subroutine"
.NXR "fputc subroutine"
.NXR "stream" "putting character on"
.NXR "stream" "putting word on"
The
.PN putc
routine appends the character
.I c
to the named output
.IR stream .
It returns the character written.
.PP
The
.PN putchar(c)
routine is defined as 
.PN putc
(c, stdout).
.PP
The
.PN fputc
routine behaves like 
.PN putc ,
but is a genuine function rather than a macro.
.PP
The
.PN putw
routine appends word (that is,
.BR int )
.I w
to the output
.IR stream .
It returns zero. 
The
.PN putw
routine neither assumes nor causes special alignment in the file.
.SH Restrictions
Because it is implemented as a macro,
.PN putc
treats a stream argument with side effects incorrectly.
In particular, `putc\^(c, *f++)\^;' doesn't work as expected.
.SH Diagnostics
The
.PN putc ,
.PN putchar ,
and
.PN fputc
functions return the constant EOF upon error.  The
.PN putw
function returns a non-zero value on error.
.SH See Also
fclose(3s), fopen(3s), fread(3s), getc(3s), printf(3s), puts(3s)