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| author | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 19:54:44 -0400 |
|---|---|---|
| committer | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 19:54:44 -0400 |
| commit | a9157ce950dfe2fc30795d43b9d79b9d1bffc48b (patch) | |
| tree | 9df484304b560466d145e662c1c254ff0e9ae0ba /static/openbsd/man3/funopen.3 | |
| parent | 160aa82b2d39c46ad33723d7d909cb4972efbb03 (diff) | |
docs: Added All OpenBSD Manuals
Diffstat (limited to 'static/openbsd/man3/funopen.3')
| -rw-r--r-- | static/openbsd/man3/funopen.3 | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/static/openbsd/man3/funopen.3 b/static/openbsd/man3/funopen.3 new file mode 100644 index 00000000..704508d5 --- /dev/null +++ b/static/openbsd/man3/funopen.3 @@ -0,0 +1,156 @@ +.\" $OpenBSD: funopen.3,v 1.20 2022/08/05 00:53:57 jsg Exp $ +.\" +.\" 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. +.\" 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. 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. +.\" +.Dd $Mdocdate: August 5 2022 $ +.Dt FUNOPEN 3 +.Os +.Sh NAME +.Nm funopen , +.Nm fropen , +.Nm fwopen +.Nd open a stream +.Sh SYNOPSIS +.In stdio.h +.Ft FILE * +.Fn funopen "const void *cookie" "int (*readfn)(void *, char *, int)" \ + "int (*writefn)(void *, const char *, int)" \ + "off_t (*seekfn)(void *, off_t, int)" \ + "int (*closefn)(void *)" +.Ft FILE * +.Fn fropen "const void *cookie" "int (*readfn)(void *, char *, int)" +.Ft FILE * +.Fn fwopen "const void *cookie" "int (*writefn)(void *, const char *, int)" +.Sh DESCRIPTION +The +.Fn funopen +function associates a stream with up to four I/O functions. +Either +.Fa readfn +or +.Fa writefn +must be specified; +the others may be given as +.Dv NULL +pointers. +These I/O functions will be used to read, write, seek, and close +the new stream. +.Pp +In general, omitting a function means that any attempt to perform the +associated operation on the resulting stream will fail. +If the close function is omitted, closing the stream will flush +any buffered output and then succeed. +.Pp +The calling conventions of +.Fa readfn , +.Fa writefn , +.Fa seekfn , +and +.Fa closefn +must match those, respectively, of +.Xr read 2 , +.Xr write 2 , +.Xr lseek 2 , +and +.Xr close 2 +with the exceptions that they are passed the +.Fa cookie +argument specified to +.Fn funopen +in place of the traditional file descriptor argument. +.Pp +Read and write I/O functions are allowed to change the underlying buffer +on fully buffered or line buffered streams by calling +.Xr setvbuf 3 . +They are also not required to completely fill or empty the buffer. +They are not, however, allowed to change streams from unbuffered to buffered +or to change the state of the line buffering flag. +They must also be prepared to have read or write calls occur on buffers other +than the one most recently specified. +.Pp +All user I/O functions can report an error by returning \-1. +Additionally, all of the functions should set the external variable +.Va errno +appropriately if an error occurs. +.Pp +An error on +.Fn closefn +does not keep the stream open. +.Pp +As a convenience, the include file +.In stdio.h +defines the macros +.Fn fropen +and +.Fn fwopen +as calls to +.Fn funopen +with only a read or write function specified. +.Sh RETURN VALUES +Upon successful completion, +.Fn funopen +returns a +.Dv FILE +pointer. +Otherwise, +.Dv NULL +is returned and the global variable +.Va errno +is set to indicate the error. +.Sh ERRORS +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fn funopen +function was called without either a read or write function. +The +.Fn funopen +function may also fail and set +.Va errno +for any of the errors specified for the routine +.Xr malloc 3 . +.El +.Sh SEE ALSO +.Xr fcntl 2 , +.Xr open 2 , +.Xr fclose 3 , +.Xr fopen 3 , +.Xr fseek 3 , +.Xr setvbuf 3 +.Sh HISTORY +The +.Fn funopen +functions first appeared in +.Bx 4.3 Net/2 . +.Sh BUGS +The +.Fn funopen +function may not be portable to systems other than +.Bx . |
