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.\"
.\" -*- nroff -*-
.\"
.\" Copyright (c) Abraham vd Merwe <abz@blio.com>
.\" All rights reserved.
.\"
.\" 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 author nor the names of other contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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.
.TH STREAM 3abz "March 2005" Unix "Library calls"
.SH NAME
stream_open, stream_read, stream_getline, stream_write, stream_close \-
cached I/O operations.
.SH LIBRARIES
Abz Library (-labz), Debug Library (-ldebug)
.SH SYNOPSIS
.nf
.B #include <abz/stream.h>
.sp
.BI "void stream_open(struct stream *" stream ", int " fd ");
.nl
.BI "ssize_t stream_read(struct stream *" stream ", void *" buf ", size_t " count ");
.nl
.BI "ssize_t stream_getline(struct stream *" stream ", char **" buf ");
.nl
.BI "ssize_t stream_write(struct stream *" stream ", const char *" buf ", size_t " count ");
.nl
.BI "void stream_close(struct stream *" stream ");
.fi
.SH DESCRIPTION
These functions perform I/O operations on a file descriptor and possibly
caches read data. These functions should not be mixed with calls to
\fBread()\fP or \fBwrite()\fP.
.PP
\fBstream_open()\fP initializes the stream structure. It should be called
before any of the other functions. The \fIfd\fP parameter should be an open
file descriptor.
.PP
\fBstream_read()\fP attempts to read up to \fIcount\fP bytes from the stream
into the buffer starting at \fIbuf\fP. If \fIcount\fP is zero, \fBread()\fP
returns zero and has no other results. If \fIcount\fP is greater than
SSIZE_MAX, the result is unspecified.
.PP
\fBstream_getline()\fP reads exactly one line of data, including the
trailing '\n' from the stream. It allocates memory for, and stores the
result in \fIbuf\fP. This function should only be called on file descriptors
with blocking I/O selected as it will only return when a newline character
is found or at the end of a file.
.PP
\fBstream_write()\fP writes up to \fIcount\fP bytes to the file referenced
by the file descriptor \fIfd\fP from the buffer starting at \fIbuf\fP.
.PP
\fBstream_close()\fP free resources allocated for the stream and close and
the file descriptor.
.SH "RETURN VALUES"
Except for \fBstream_open()\fP and \fBstream_close()\fP, all of these
functions return the number of bytes transferred or -1 if an error occurred.
Call \fBabz_get_error()\fP to retrieve error messages.
.SH "NOTES"
None of the libabz routines are thread-safe. I'm not planning to change this
either! For more information, please see http://threading.2038bug.com/
.SH "SEE ALSO"
abz_get_error(3)
.SH "AUTHOR"
Written by Abraham vd Merwe <abz@blio.com>
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