ssh2/docs/libssh2_channel_write_ex.3
James Housley 4b8db8c1ab Modify the code to truely support non-blocking. Propogate the EAGAIN error
all the way up to the user interface.  All code modules bug sftp.c have
been completed.

Functions that return an "int", or similar return LIBSSH2CHANNEL_EAGAIN to
indicate some part of the call would block, in non-blocking mode.

Functions that return a structure, like "LIBSSH2_CHANNEL *", return NULL
and set the libssh2 error.  The error can be obtained with either
libssh2_session_last_error() or libssh2_session_last_errno().  Either of
these will return the error code of LIBSSH2_ERROR_EAGAIN if the
call would block, in non-blocking mode.

The current state of a function and some variable are keep in the
structures so that on the next call the operation that would block can
be retried again with the same data.
2007-06-06 12:34:06 +00:00

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1.5 KiB
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.\" $Id: libssh2_channel_write_ex.3,v 1.2 2007/06/06 12:34:06 jehousley Exp $
.\"
.TH libssh2_channel_write_ex 3 "1 June 2007" "libssh2 0.15" "libssh2 manual"
.SH NAME
libssh2_channel_write_ex - write data to a channel stream blocking
.SH SYNOPSIS
#include <libssh2.h>
size_t libssh2_channel_write_ex(LIBSSH2_CHANNEL *channel, int stream_id,
char *buf, size_t buflen);
size_t libssh2_channel_write(LIBSSH2_CHANNEL *channel, char *buf,
size_t buflen);
size_t libssh2_channel_write_stderr(LIBSSH2_CHANNEL *channel, char *buf,
size_t buflen);
.SH DESCRIPTION
Write data to a channel stream. All channel streams have one standard I/O
substream (stream_id == 0), and may have up to 2^32 extended data streams as
identified by the selected \fIstream_id\fP. The SSH2 protocol currently
defines a stream ID of 1 to be the stderr substream.
\fIchannel\fP - active channel stream to write to.
\fIstream_id\fP - substream ID number (e.g. 0 or SSH_EXTENDED_DATA_STDERR)
\fIbuf\fP - pointer to buffer to write
\fIbuflen\fP - size of the data to write
\fIlibssh2_channel_write(3)\fP and \fIlibssh2_channel_write_stderr(3)\fP are
macros.
.SH RETURN VALUE
Actual number of bytes written or negative on failure.
LIBSSH2CHANNEL_EAGAIN when it would otherwise block. While
LIBSSH2CHANNEL_EAGAIN is a negative number, it isn't really a failure per se.
.SH "SEE ALSO"
.BR libssh2_channel_open_session(3)
.BR libssh2_channel_read(3)