mirror of
https://github.com/GnoConsortium/gno.git
synced 2024-09-11 14:54:54 +00:00
251 lines
6.2 KiB
Groff
251 lines
6.2 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" Chris Torek and the American National Standards Committee X3,
|
|
.\" on Information Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)fopen.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.TH FOPEN 3 "29 April 1997" GNO "Library Routines"
|
|
.SH NAME
|
|
.BR fopen ,
|
|
.BR fdopen ,
|
|
.BR freopen
|
|
\- stream open functions
|
|
.SH SYNOPSIS
|
|
#include <stdio.h>
|
|
.sp 1
|
|
FILE *\fBfopen\fR(const char *\fIpath\fR, const char *\fImode\fR);
|
|
.sp 1
|
|
FILE *\fBfdopen\fR(int \fIfildes\fR, const char *\fImode\fR);
|
|
.sp 1
|
|
FILE *\fBfreopen\fR(const char *\fIpath\fR, const char *\fImode\fR, FILE *\fIstream\fR);
|
|
.SH DESCRIPTION
|
|
The
|
|
.BR fopen
|
|
function
|
|
opens the file whose name is the string pointed to by
|
|
.I path
|
|
and associates a stream with it.
|
|
.LP
|
|
The argument
|
|
.I mode
|
|
points to a string beginning with one of the following
|
|
sequences (Additional characters may follow these sequences.):
|
|
.RS
|
|
.IP \fBr\fR
|
|
Open text file for reading.
|
|
The stream is positioned at the beginning of the file.
|
|
.IP \fBr+\fR
|
|
Open for reading and writing.
|
|
The stream is positioned at the beginning of the file.
|
|
.IP \fBw\fR
|
|
Truncate file to zero length or create text file for writing.
|
|
The stream is positioned at the beginning of the file.
|
|
.IP \fBw+\fR
|
|
Open for reading and writing.
|
|
The file is created if it does not exist, otherwise it is truncated.
|
|
The stream is positioned at the beginning of the file.
|
|
.IP \fBa\fR
|
|
Open for writing.
|
|
The file is created if it does not exist.
|
|
The stream is positioned at the end of the file.
|
|
.IP \fBa+\fR
|
|
Open for reading and writing.
|
|
The file is created if it does not exist.
|
|
The stream is positioned at the end of the file.
|
|
.RE
|
|
.LP
|
|
The
|
|
.I mode
|
|
string can also include the letter ``b'' either as a third character or
|
|
as a character between the characters in any of the two-character strings
|
|
described above.
|
|
If the ``b'' is
|
|
.I not
|
|
specified, then the file is assumed to contain text.
|
|
On input, carrige returns (``\\r'') will be translated into
|
|
line feeds (``\\n'').
|
|
The reverse translation will occur on output.
|
|
If the ``b''
|
|
.I is
|
|
specified, no such translation will occur.
|
|
.LP
|
|
Any created files will have mode
|
|
.BR S_IRUSR
|
|
\&|
|
|
.BR S_IWUSR
|
|
\&|
|
|
.BR S_IRGRP
|
|
\&|
|
|
.BR S_IWGRP
|
|
\&|
|
|
.BR S_IROTH
|
|
\&|
|
|
.BR S_IWOTH " (0666),"
|
|
as modified by the process'
|
|
umask value (see
|
|
.BR umask (2)).
|
|
.LP
|
|
The
|
|
.BR fdopen
|
|
function associates a stream with the existing file descriptor,
|
|
.IR fildes
|
|
The
|
|
.I mode
|
|
of the stream must be compatible with the mode of the file descriptor.
|
|
See the section on BUGS.
|
|
.LP
|
|
The
|
|
.BR freopen
|
|
function
|
|
opens the file whose name is the string pointed to by
|
|
.I path
|
|
and associates the stream pointed to by
|
|
.I stream
|
|
with it.
|
|
The original stream (if it exists) is closed.
|
|
The
|
|
.I mode
|
|
argument is used just as in the
|
|
.BR fopen
|
|
function.
|
|
The primary use of the
|
|
.BR freopen
|
|
function
|
|
is to change the file associated with a
|
|
standard text stream
|
|
.IR ( stderr ,
|
|
.IR stdin ,
|
|
or
|
|
.IR stdout ).
|
|
.SH RETURN VALUES
|
|
Upon successful completion
|
|
.BR fopen ,
|
|
.BR fdopen
|
|
and
|
|
.BR freopen
|
|
return a FILE
|
|
pointer.
|
|
Otherwise,
|
|
.BR NULL
|
|
is returned and the global variable
|
|
.IR errno
|
|
is set to indicate the error.
|
|
.SH ERRORS
|
|
.RS
|
|
.IP \fBEINVAL\fR
|
|
The
|
|
.I mode
|
|
provided to
|
|
.BR fopen ,
|
|
.BR fdopen ,
|
|
or
|
|
.BR freopen
|
|
was invalid.
|
|
.RE
|
|
.LP
|
|
The
|
|
.BR fopen ,
|
|
.BR fdopen
|
|
and
|
|
.BR freopen
|
|
functions
|
|
may also fail and set
|
|
.IR errno
|
|
for any of the errors specified for the routine
|
|
.BR malloc (3).
|
|
.LP
|
|
The
|
|
.BR fopen
|
|
function
|
|
may also fail and set
|
|
.IR errno
|
|
for any of the errors specified for the routine
|
|
.BR open (2).
|
|
.LP
|
|
The
|
|
.BR fdopen
|
|
function
|
|
may also fail and set
|
|
.IR errno
|
|
for any of the errors specified for the routine
|
|
.BR fcntl (2)
|
|
or
|
|
.BR stat (2).
|
|
.LP
|
|
The
|
|
.BR freopen
|
|
function
|
|
may also fail and set
|
|
.IR errno
|
|
for any of the errors specified for the routines
|
|
.BR open (2),
|
|
.BR fclose (3)
|
|
and
|
|
.BR fflush (3).
|
|
.SH BUGS
|
|
If
|
|
.BR fdopen
|
|
is passed a file descriptor in use by another stdio stream (such
|
|
as that available from the
|
|
.BR fileno
|
|
macro),
|
|
the result is currently undefined.
|
|
If you need to do such an operation, you should
|
|
.BR dup (2)
|
|
the result of the
|
|
.BR fileno
|
|
macro before passing it to
|
|
.BR fdopen .
|
|
.LP
|
|
Access bits are not currently checked for any file descriptor passed to
|
|
.BR fdopen
|
|
which is a character-special file.
|
|
.SH SEE ALSO
|
|
.BR open (2),
|
|
.BR stat (2),
|
|
.BR fclose (3),
|
|
.BR fseek (3),
|
|
.BR funopen (3)
|
|
.SH STANDARDS
|
|
The
|
|
.BR fopen
|
|
and
|
|
.BR freopen
|
|
functions
|
|
conform to ANSI/C.
|
|
The
|
|
.BR fdopen
|
|
function
|
|
conforms to POSIX 1003.1 (1988).
|