libssh2\_channel\_read\_ex(3) libssh2 libssh2\_channel\_read\_ex(3) # [NAME](#NAME) libssh2\_channel\_read\_ex - read data from a channel stream # [SYNOPSIS](#SYNOPSIS) ``` #include ssize_t libssh2_channel_read_ex(LIBSSH2_CHANNEL *channel, int stream_id, char *buf, size_t buflen); ssize_t libssh2_channel_read(LIBSSH2_CHANNEL *channel, char *buf, size_t buflen); ssize_t libssh2_channel_read_stderr(LIBSSH2_CHANNEL *channel, char *buf, size_t buflen); ``` # [DESCRIPTION](#DESCRIPTION) Attempt to read data from an active 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 *stream\_id*. The SSH2 protocol currently defines a stream ID of 1 to be the stderr substream. *channel* - active channel stream to read from. *stream\_id* - substream ID number (e.g. 0 or SSH\_EXTENDED\_DATA\_STDERR) *buf* - pointer to storage buffer to read data into *buflen* - size of the buf storage [*libssh2\_channel\_read(3)*](/man/os/libssh2/libssh2_channel_read.3) and [*libssh2\_channel\_read\_stderr(3)*](/man/os/libssh2/libssh2_channel_read_stderr.3) are macros. # [RETURN VALUE](#RETURN_VALUE) Actual number of bytes read or negative on failure. It returns LIBSSH2\_ERROR\_EAGAIN when it would otherwise block. While LIBSSH2\_ERROR\_EAGAIN is a negative number, it is not really a failure per se. Note that a return value of zero (0) can in fact be a legitimate value and only signals that no payload data was read. It is not an error. # [ERRORS](#ERRORS) *LIBSSH2\_ERROR\_SOCKET\_SEND* - Unable to send data on socket. *LIBSSH2\_ERROR\_CHANNEL\_CLOSED* - The channel has been closed. # [SEE ALSO](#SEE_ALSO) [**libssh2\_poll\_channel\_read(3)**](/man/os/libssh2/libssh2_poll_channel_read.3) 1 Jun 2007 libssh2 0.15 --- Document: libssh2_channel_read_ex(3) from libssh2 1.11.1-r11 (Chainguard OS) Source: https://github.com/libssh2/libssh2.git