libssh2

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.\" Copyright (C) The libssh2 project and its contributors.
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.\" SPDX-License-Identifier: BSD-3-Clause
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.TH libssh2_channel_read_ex 3 "1 Jun 2007" "libssh2 0.15" "libssh2"
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.SH NAME
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libssh2_channel_read_ex - read data from a channel stream
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.SH SYNOPSIS
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.nf
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#include <libssh2.h>
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ssize_t
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libssh2_channel_read_ex(LIBSSH2_CHANNEL *channel, int stream_id,
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                        char *buf, size_t buflen);
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ssize_t
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libssh2_channel_read(LIBSSH2_CHANNEL *channel,
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                     char *buf, size_t buflen);
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ssize_t
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libssh2_channel_read_stderr(LIBSSH2_CHANNEL *channel,
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                            char *buf, size_t buflen);
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.fi
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.SH DESCRIPTION
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Attempt to read data from an active channel stream. All channel streams have
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one standard I/O substream (stream_id == 0), and may have up to 2^32 extended
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data streams as identified by the selected \fIstream_id\fP. The SSH2 protocol
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currently defines a stream ID of 1 to be the stderr substream.
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\fIchannel\fP - active channel stream to read from.
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\fIstream_id\fP - substream ID number (e.g. 0 or SSH_EXTENDED_DATA_STDERR)
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\fIbuf\fP - pointer to storage buffer to read data into
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\fIbuflen\fP - size of the buf storage
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\fIlibssh2_channel_read(3)\fP and \fIlibssh2_channel_read_stderr(3)\fP are
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macros.
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.SH RETURN VALUE
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Actual number of bytes read or negative on failure. It returns
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LIBSSH2_ERROR_EAGAIN when it would otherwise block. While
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LIBSSH2_ERROR_EAGAIN is a negative number, it is not really a failure per se.
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Note that a return value of zero (0) can in fact be a legitimate value and
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only signals that no payload data was read. It is not an error.
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.SH ERRORS
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\fILIBSSH2_ERROR_SOCKET_SEND\fP - Unable to send data on socket.
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\fILIBSSH2_ERROR_CHANNEL_CLOSED\fP - The channel has been closed.
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.SH SEE ALSO
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.BR libssh2_poll_channel_read(3)
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