+++ /dev/null
-.\" Copyright (c) 1990, 1991 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.
-.\"
-.\" %%%LICENSE_START(BSD_4_CLAUSE_UCB)
-.\" 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
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-.\" %%%LICENSE_END
-.\"
-.\" @(#)fopen.3 6.8 (Berkeley) 6/29/91
-.\"
-.\" Converted for Linux, Mon Nov 29 15:22:01 1993, faith@cs.unc.edu
-.\" Modified, aeb, 960421, 970806
-.\" Modified, joey, aeb, 2002-01-03
-.\"
-.TH FOPEN 3 2012-04-22 "GNU" "Linux Programmer's Manual"
-.SH NAME
-fopen, fdopen, freopen \- stream open functions
-.SH SYNOPSIS
-.nf
-.B #include <stdio.h>
-.sp
-.BI "FILE *fopen(const char *" path ", const char *" mode );
-
-.BI "FILE *fdopen(int " fd ", const char *" mode );
-
-.BI "FILE *freopen(const char *" path ", const char *" mode ", FILE *" stream );
-.fi
-.sp
-.in -4n
-Feature Test Macro Requirements for glibc (see
-.BR feature_test_macros (7)):
-.in
-.sp
-.BR fdopen ():
-_POSIX_C_SOURCE\ >=\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE
-.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.
-.PP
-The argument
-.I mode
-points to a string beginning with one of the following sequences
-(possibly followed by additional characters, as described below):
-.TP
-.B r
-Open text file for reading.
-The stream is positioned at the beginning of the file.
-.TP
-.B r+
-Open for reading and writing.
-The stream is positioned at the beginning of the file.
-.TP
-.B w
-Truncate file to zero length or create text file for writing.
-The stream is positioned at the beginning of the file.
-.TP
-.B w+
-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.
-.TP
-.B a
-Open for appending (writing at end of file).
-The file is created if it does not exist.
-The stream is positioned at the end of the file.
-.TP
-.B a+
-Open for reading and appending (writing at end of file).
-The file is created if it does not exist.
-The initial file position for reading is at the beginning of the file,
-but output is always appended to the end of the file.
-.PP
-The
-.I mode
-string can also include the letter \(aqb\(aq either as a last character or as
-a character between the characters in any of the two-character strings
-described above.
-This is strictly for compatibility with C89
-and has no effect; the \(aqb\(aq is ignored on all POSIX
-conforming systems, including Linux.
-(Other systems may treat text files and binary files differently,
-and adding the \(aqb\(aq may be a good idea if you do I/O to a binary
-file and expect that your program may be ported to non-UNIX
-environments.)
-.PP
-See NOTES below for details of glibc extensions for
-.IR mode .
-.PP
-Any created files will have mode
-.BR S_IRUSR " | " S_IWUSR " | " S_IRGRP " | " S_IWGRP " | " S_IROTH " | " S_IWOTH
-(0666), as modified by the process's umask value (see
-.BR umask (2)).
-.PP
-Reads and writes may be intermixed on read/write streams in any order.
-Note that ANSI C requires that a file positioning function intervene
-between output and input, unless an input operation encounters end-of-file.
-(If this condition is not met, then a read is allowed to return the
-result of writes other than the most recent.)
-Therefore it is good practice (and indeed sometimes necessary
-under Linux) to put an
-.BR fseek (3)
-or
-.BR fgetpos (3)
-operation between write and read operations on such a stream.
-This operation may be an apparent no-op
-(as in \fIfseek(..., 0L, SEEK_CUR)\fP
-called for its synchronizing side effect).
-.PP
-Opening a file in append mode (\fBa\fP as the first character of
-.IR mode )
-causes all subsequent write operations to this stream to occur
-at end-of-file, as if preceded the call:
-.nf
-
- fseek(stream, 0, SEEK_END);
-.fi
-.PP
-The
-.BR fdopen ()
-function associates a stream with the existing file descriptor,
-.IR fd .
-The
-.I mode
-of the stream (one of the values "r", "r+", "w", "w+", "a", "a+")
-must be compatible with the mode of the file descriptor.
-The file position indicator of the new stream is set to that
-belonging to
-.IR fd ,
-and the error and end-of-file indicators are cleared.
-Modes "w" or "w+" do not cause truncation of the file.
-The file descriptor is not dup'ed, and will be closed when
-the stream created by
-.BR fdopen ()
-is closed.
-The result of applying
-.BR fdopen ()
-to a shared memory object is undefined.
-.PP
-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
-.RI ( stderr ", " stdin ", or " stdout ).
-.SH RETURN VALUE
-Upon successful completion
-.BR fopen (),
-.BR fdopen ()
-and
-.BR freopen ()
-return a
-.I FILE
-pointer.
-Otherwise, NULL is returned and
-.I errno
-is set to indicate the error.
-.SH ERRORS
-.TP
-.B EINVAL
-The
-.I mode
-provided to
-.BR fopen (),
-.BR fdopen (),
-or
-.BR freopen ()
-was invalid.
-.PP
-The
-.BR fopen (),
-.BR fdopen ()
-and
-.BR freopen ()
-functions may also fail and set
-.I errno
-for any of the errors specified for the routine
-.BR malloc (3).
-.PP
-The
-.BR fopen ()
-function may also fail and set
-.I errno
-for any of the errors specified for the routine
-.BR open (2).
-.PP
-The
-.BR fdopen ()
-function may also fail and set
-.I errno
-for any of the errors specified for the routine
-.BR fcntl (2).
-.PP
-The
-.BR freopen ()
-function may also fail and set
-.I errno
-for any of the errors specified for the routines
-.BR open (2),
-.BR fclose (3),
-and
-.BR fflush (3).
-.SH CONFORMING TO
-The
-.BR fopen ()
-and
-.BR freopen ()
-functions conform to C89.
-The
-.BR fdopen ()
-function conforms to POSIX.1-1990.
-.SH NOTES
-.SS Glibc notes
-The GNU C library allows the following extensions for the string specified in
-.IR mode :
-.TP
-.BR c " (since glibc 2.3.3)"
-Do not make the open operation,
-or subsequent read and write operations,
-thread cancellation points.
-This flag is ignored for
-.BR fdopen ().
-.TP
-.BR e " (since glibc 2.7)"
-Open the file with the
-.B O_CLOEXEC
-flag.
-See
-.BR open (2)
-for more information.
-This flag is ignored for
-.BR fdopen ().
-.TP
-.BR m " (since glibc 2.3)"
-Attempt to access the file using
-.BR mmap (2),
-rather than I/O system calls
-.RB ( read (2),
-.BR write (2)).
-Currently,
-.\" As at glibc 2.4:
-use of
-.BR mmap (2)
-is attempted only for a file opened for reading.
-.TP
-.B x
-.\" Since glibc 2.0?
-.\" FIXME . C11 specifies this flag
-Open the file exclusively
-(like the
-.B O_EXCL
-flag of
-.BR open (2)).
-If the file already exists,
-.BR fopen ()
-fails, and sets
-.I errno
-to
-.BR EEXIST .
-This flag is ignored for
-.BR fdopen ().
-.PP
-In addition to the above characters,
-.BR fopen ()
-and
-.BR freopen ()
-support the following syntax
-in
-.IR mode :
-
-.BI " ,ccs=" string
-
-The given
-.I string
-is taken as the name of a coded character set and
-the stream is marked as wide-oriented.
-Thereafter, internal conversion functions convert I/O
-to and from the character set
-.IR string .
-If the
-.BI ,ccs= string
-syntax is not specified,
-then the wide-orientation of the stream is
-determined by the first file operation.
-If that operation is a wide-character operation,
-the stream is marked wide-oriented,
-and functions to convert to the coded character set are loaded.
-.SH BUGS
-When parsing for individual flag characters in
-.IR mode
-(i.e., the characters preceding the "ccs" specification),
-the glibc implementation of
-.\" FIXME . http://sourceware.org/bugzilla/show_bug.cgi?id=12685
-.BR fopen ()
-and
-.BR freopen ()
-limits the number of characters examined in
-.I mode
-to 7 (or, in glibc versions before 2.14, to 6,
-which was not enough to include possible specifications such as "rb+cmxe").
-The current implementation of
-.BR fdopen ()
-parses at most 5 characters in
-.IR mode .
-.SH SEE ALSO
-.BR open (2),
-.BR fclose (3),
-.BR fileno (3),
-.BR fmemopen (3),
-.BR fopencookie (3)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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