Admin at 22:16, 12 December 2014

2014-12-12T22:16:47Z

Admin: Created page with "= Action = Reads data from an open socket connection. ..."

2013-02-12T17:56:59Z

Created page with "= Action = Reads data from an open socket connection. ..."

Neue Seite

= Action =

Reads data from an open socket connection.

 

 

= Syntax =

Result = TCPREAD( socket , var, bytes)

 

 

= Remarks =
<div style="padding: 0px; margin: 0px 0px 0px 4px;">
{| width="609" cellspacing="0" cellpadding="1" border="1" style="border: 2px solid rgb(0, 0, 0); border-spacing: 0px; border-collapse: collapse;"
|- style="vertical-align: top;"
| valign="top" width="13%" style="width: 75px; border: 1px solid rgb(0, 0, 0);" |
Result

| valign="top" width="100%" style="width: 525px; border: 1px solid rgb(0, 0, 0);" |
A byte variable that will be assigned with 0, when no errors occurred.

When an error occurs, the value will be set to 1.

 

When there are not enough bytes in the reception buffer, the routine will wait until there is enough data or the socket is closed.

|- style="vertical-align: top;"
| valign="top" width="13%" style="width: 75px; border: 1px solid rgb(0, 0, 0);" |
socket

| valign="top" width="100%" style="width: 525px; border: 1px solid rgb(0, 0, 0);" |
The socket number you want to read data from (0-3). Or 0-7 for W5200/W5300.

|- style="vertical-align: top;"
| valign="top" width="13%" style="width: 75px; border: 1px solid rgb(0, 0, 0);" |
Var

| valign="top" width="100%" style="width: 525px; border: 1px solid rgb(0, 0, 0);" |
The name of the variable that will be assigned with the data from the socket.

|- style="vertical-align: top;"
| valign="top" width="13%" style="width: 75px; border: 1px solid rgb(0, 0, 0);" |
Bytes

| valign="top" width="100%" style="width: 525px; border: 1px solid rgb(0, 0, 0);" |
The number of bytes to read. Only valid for non-string variables.

|}
</div>
 

When you use TCPread with a string variable, the routine will wait for CR + LF and it will return the data without the CR + LF.

For strings, the function will not overwrite the string.

 

For example, your string is 10 bytes long and the line you receive is 80 bytes long, you will receive only the first 10 bytes after CR + LF is encountered.

Also, for string variables, you do not need to specify the number of bytes to read since the routine will wait for CR + LF.

 

For other data types you need to specify the number of bytes.

There will be no check on the length so specifying to receive 2 bytes for a byte will overwrite the memory location after the memory location of the byte.

 

You should only attempt to read data if you have determined with the SocketStat function, that there is actual data in the receive buffer.

 

 

= See also =

[[CONFIG TCPIP]], [[GETSOCKET]] , [[SOCKETCONNECT]], [[SOCKETSTAT]] , [[TCPWRITE]], [[TCPWRITESTR]], [[SOCKETCLOSE]] ,[[SOCKETLISTEN]], [[SOCKETDISCONNECT]]

 

 

= Partial Example =

 <source lang="bascomavr">
Result = Socketstat(idx , Sel_recv) ' get number of bytes waiting
If Result > 0 Then
Result = Tcpread(idx , S)
End If
</source> {{Languages}}

[[Category:BASCOM Language Reference]]

@@ Zeile 78: / Zeile 78: @@
 <span style="font-family: Arial;">&nbsp;</span>
-<span style="font-family: Arial;">&nbsp;</span>
+<span style="font-family: Arial;">&nbsp;</span><span style="font-size: 10pt;">$BIGSTRINGS are not supported by TCPREAD.</span>
 = <span class="f_Header">See also</span> =

TCPREAD - Revision history

Admin at 22:16, 12 December 2014

Admin: Created page with "= Action = Reads data from an open socket connection. ..."