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{{mirc title|/sockread Command}}
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{{mIRC menu}}
 
The '''/sockread''' command reads bytes from the receive buffer of a socket connection into a specified variable. This command must be and is to be used inside socket events.
 
The '''/sockread''' command reads bytes from the receive buffer of a socket connection into a specified variable. This command must be and is to be used inside socket events.
  
 
mIRC in general only understand {{mIRC|$crlf}} terminated line. With socket, mIRC only understands {{mIRC|$lf}} terminated line (any {{mirc|$cr}} before a {{mirc|$lf}} is removed).
 
mIRC in general only understand {{mIRC|$crlf}} terminated line. With socket, mIRC only understands {{mIRC|$lf}} terminated line (any {{mirc|$cr}} before a {{mirc|$lf}} is removed).
  
The number of bytes waiting to be read can be retrieved using {{mIRC|$sock|$sock(name).rq}}
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The number of bytes waiting to be read can be retrieved using {{mIRC|$sock|$sock(name).rq)
  
 
By default:
 
By default:
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== Synopsis ==
 
== Synopsis ==
<source lang="mIRC">
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<source lang="mIRC">/sockread [-fn] [numbytes] <%var|&binvar></source>
/sockread [-fn] <%var|&binvar>
 
/sockread [numbytes] <%var|&binvar>
 
</source>
 
  
 
== Switches ==
 
== Switches ==
{| class="wikitable" style="line-height: 25px;"
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{| class="wikitable" style="line-height: 25px; margin-left: 75px;"
 
|-
 
|-
 
! Switch !! Description
 
! Switch !! Description
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| '''f''' || When reading a terminated line (/sockread %var or /sockread -n &var), forces mIRC to fill the variable with whatever text is in the receive buffer, even if it does not end in a terminated line.
 
| '''f''' || When reading a terminated line (/sockread %var or /sockread -n &var), forces mIRC to fill the variable with whatever text is in the receive buffer, even if it does not end in a terminated line.
 
|-
 
|-
| '''n''' || Reads a terminated line into a {{mIRC|binary variables|&binvars}}. If the incoming line does not contain a terminated line, no byte will be read into the {{mIRC|binary variables|&binvars}}, unless you specify the '''-f''' switch.
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| '''n''' || Reads a terminated line into a {{mIRC|binary variables|&binvars}}. If the incoming line does not contain a terminated line, no bytes will be read into the {{mIRC|binary variables|&binvars}}, unless you specify the '''-f''' switch.
 
|}
 
|}
  
 
== Parameters ==
 
== Parameters ==
{| class="wikitable" style="line-height: 25px;"
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{| class="wikitable" style="line-height: 25px; margin-left: 75px;"
 
|-
 
|-
 
! Parameter !! Description
 
! Parameter !! Description
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     b) you were reading into a %var and there is still a terminated line in the buffer waiting to be read.  
 
     b) you were reading into a %var and there is still a terminated line in the buffer waiting to be read.  
  
This means you will miss the last line if it is not a terminated line and you are reading line by line only (and not in a binvar, although it's also easier to use on sockclose with binvar if you are reading line by line and facing this). You can read that line in the on sockclose event, {{mIRC|/sockread#Last line not showing up|see below}}.
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This means you will miss the last line if it does not end with a terminated line and you are reading line by line only.
  
'''Note''' (fixed since mIRC 7.36): Using SSL, on sockread might not be retriggered as it should, {{mIRC|on events/on sockclose|on sockclose}} will be triggered too early with $sockerr sets to 3, you must read the receive buffer from that event
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'''Note''': It is possible to read such a last line inside the on sockclose event.
  
 +
'''Note2''': Using SSL, on sockread might not be retriggered as it should, {{mIRC|on sockclose}} will be triggered too early with $sockerr sets to 3, you must read the receive buffer from that event
  
It is important to note that the data received will vary in size. Practically speaking, we receive several kilobytes per second, it is easy to assume that the data you want is going to be sent and received the same way and above all, the way you want, but that's incorrect, you might receive very small packet at a very small speed.
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It is important to note that the data received will vary. Practically speaking, we receive several kilobytes per second, it is easy to assume that the data you want is going to be sent and received the same way and above all, the way you want, but that's incorrect, you might receive very small packet at a very small speed.
  
 
A common situation when dealing with HTML is to check the source of the page you are working with, to identify something that is unlikley to change, and to use that as a reference. Doing this is not bad, but the way it is usually implemented by mIRC user is incorrect.
 
A common situation when dealing with HTML is to check the source of the page you are working with, to identify something that is unlikley to change, and to use that as a reference. Doing this is not bad, but the way it is usually implemented by mIRC user is incorrect.
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  }
 
  }
 
}</source>
 
}</source>
If you do that, you cannot guarantee it will work 100% of the time.
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If you do that, you cannot guarantee it will work 100% of the time, you cannot read the content of the received buffer, if the received buffer is filled with a few bytes and ends up being "this is my ref" when on sockread triggers, the if statement won't be true, for example here, the next time the event triggers, you might have a received buffer containing "erence:", but it might be "erence:\r\nI want that line" as well.
  
If the received buffer is filled with a few bytes and ends up being "this is my ref" when on sockread triggers, the -f switch will force mirc to read that, and you won't be able to match your full line, for example here, the next time the event triggers, you might have a received buffer containing "erence:", but it might be "erence:\r\nI want that line" as well, screwing you anyway.
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This scenario is very unlikely to happen, because you are reading line by line, which is much much slower than reading the whole content of the received buffer and as such, the received buffer is filled by mIRC faster than your socket code reads it. But it is still possible.
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You can fix this by changing the logic of your event to use /sockread %a instead of /sockread -f %a. Indeed, not using the -f switch, mIRC will only read data if you have a terminated line in the received buffer, so if you check $sockbr, (the number of bytes read), you can /return in the event if it's 0 and wait for it to retrigger, hopfully this time a terminated line will be in the received buffer. If you do this change and still need to get the last non terminated line, you will need do so inside the on sockclose event, no problem otherwise:
  
So you might think here "let's not use -f then":
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'''Note''': In this case we could ditch the "if ($sockbr == 0) return" because %a wouldn't be equal to "this is my reference:" anyway, but you could be checking that %a is $null there, so generally speaking you should use it in this situation
  
 
<source lang="mIRC">
 
<source lang="mIRC">
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  var %a
 
  var %a
 
  sockread %a
 
  sockread %a
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if ($sockbr == 0) return
 +
;guaranteed to get %a with a full line.
 
  if (%a == this is my reference:) {
 
  if (%a == this is my reference:) {
 
     ...
 
     ...
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}</source>
 
}</source>
  
And that, assuming what you are looking for is not on the last non terminated line (which would be missed because -f is not there, although note that you can read that last non terminated line inside the {{mIRC|on sockclose}} event), should be fine. In fact, in this specific example and in general, it will work, because you are making sure %a is a full line or nothing. Well that's why it works in most situation, you are checking that %a is a specific text, which would fail if no byte were read into %a because a terminated line couldn't be found. However, if you are in a situation where you must check that %a is $null (usually because it read an empty $crlf line), you must check {{mIRC|$sockbr}} to know if you read bytes at all, a good example of this usage is shown below, which discard the headers of HTTP (check for an empty value after /Sockread %a reads an empty $crlf line):
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Another solution consists in making a buffer by yourself and adding what you are reading to it, until you get the correct portion you want (a terminated line in this example).
 
 
<source lang="mIRC">
 
alias testHTTP {
 
sockclose testHTTP
 
sockopen testHTTP mirc.com 80
 
}
 
 
 
on *:sockopen:testHTTP:{
 
if (!$sockerr) {
 
  sockwrite -n $sockname GET / HTTP/1.1
 
  sockwrite -n $sockname Host: mirc.com
 
  sockwrite -n $sockname
 
}
 
}
 
on *:sockread:testHTTP:{
 
if (!$sockerr) {
 
  if ($sock($sockname).mark) {
 
  ; here you can start reading the real source the way you want
 
  }
 
  else {
 
    var %a
 
    sockread %a
 
    if ($sockbr) {
 
    if (%a == $null) sockmark $sockname 1
 
    }
 
  }
 
}
 
}</source>
 
 
 
Getting problem because you are not checking properly for $sockbr is very unlikely to happen if you are reading line by line, because it is much much slower than reading the whole content of the received buffer and as such, the received buffer is filled by mIRC faster than your socket code reads it. But it is still possible.
 
 
 
Another solution consists in making a buffer by yourself and adding what you are reading to it, until you get the correct portion you want (a terminated line in these examples).
 
  
 
If you are reading the whole content of the received buffer with one /sockread using binary variable or just large portion of the received buffer in a binary variable, you are more likely to see the  
 
If you are reading the whole content of the received buffer with one /sockread using binary variable or just large portion of the received buffer in a binary variable, you are more likely to see the  
issue because you are basically reading the buffer as fast as mIRC fills it (or faster than line by line for large portion). The same solutions exists for binary variables, use /sockread -n to read a terminated line into the binvar, check $sockbr to make sure you read something etc. Using $bfind is the correct way to parse, unless you have very good evidence about the length of the lines you are going to receive and you want to go the easy way: if (text operator $bvar(&a,1,4096)) or similar.
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issue because you are basically reading the buffer as fast as mIRC fills it (or faster than line by line for large portion). The same solutions exists for binary variables, use /sockread -n to read a terminated line into the binvar, check $sockbr to make sure you read something (cause if so, a whole line has been read).
  
 
* Reading from the receive buffer
 
* Reading from the receive buffer
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</source>
 
</source>
  
'''General Note''': it can be a good idea and might be simpler for you to read everything to a file and then parse that file.
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'''General Note''': if you want to avoid any issue, you should write the whole source to a file and then parse that file, this might be easier.
 
 
== Last line not showing up ==
 
 
 
Another common problem is reading the last line sent by an HTTP server, which isn't a terminated line (no $crlf or $lf).
 
 
 
Indeed, if you are using /sockread %var, you're will read properly line by line but that last line won't be read by this sockread command.
 
 
 
We also saw how this non terminated line in the received buffer wouldn't make mIRC retrigger the on sockread event.
 
 
 
One solution which doesn't involve more than that, is to read that line from the on sockclose event, indeed you are sure on sockread read the previous line, so inside on sockclose, you should get only that last non terminated line, this time we use the -f switch to force the read:
 
 
 
<source lang="mIRC">
 
on *:sockclose:name:{
 
  if (!$sockerr) {
 
  var %a
 
  sockread -f %a
 
  if ($sockbr == 0) return
 
  echo -a > %a
 
}
 
}
 
</source>
 
 
 
If you are using HTTP 1.1 and you actually want the socket to remain open, you would need to grab the value of the content-length header, store that in a variable and increase another variable with the length of what you are reading, if the length of the received buffer + the value of that variable equal the value of the content length, you should first try to see if you have a line by reading with /sockread %a, and if no byte is read, then use /sockread -f %a.
 
  
 
== Example ==
 
== Example ==
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'''Note2''': too long line will produce an error.
 
'''Note2''': too long line will produce an error.
  
'''Note3''': Using SSL, the on sockread event might not be triggered though it should, you must read the rest in the on sockclose event (has been fixed since mIRC 7.36).
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'''Note3''': Using SSL, the sockread might not be triggered though there are still datas to be read, you must read the rest in the on sockclose event.
  
 
<source lang="mIRC">ON *:SOCKREAD:mySocket:{
 
<source lang="mIRC">ON *:SOCKREAD:mySocket:{
 
   var %a
 
   var %a
 
   if ($sockerr > 0) { return }
 
   if ($sockerr > 0) { return }
   sockread %a
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   sockread -f %a
   if (!$sockbr) return
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   echo -s > %a
 
   while ($sockbr) {
 
   while ($sockbr) {
     echo -a > %a
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     sockread -f %a
     sockread %a
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     echo -s > %a
 
   }
 
   }
 
}
 
}
 
</source>
 
</source>
 
'''Note''': as we just saw, if the last line in the source does not end with a terminated line, it won't be read by that event.
 
  
 
If you ever worked with HTTP 1.1, you know that it can send data in chunk, here is a way to write the real content to a file:
 
If you ever worked with HTTP 1.1, you know that it can send data in chunk, here is a way to write the real content to a file:
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   ... your request...
 
   ... your request...
 
   sockmark $sockname 0
 
   sockmark $sockname 0
   ;we write to source.txt
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   ;write to source.Txt
 
   .remove source.txt
 
   .remove source.txt
 
   unset %bytestoread
 
   unset %bytestoread
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         sockread %bytestoread &a
 
         sockread %bytestoread &a
 
         bwrite source.txt -1 -1 &a
 
         bwrite source.txt -1 -1 &a
         ;but $sockbr tells us how much we read, we decrease by that number (in case we received something smaller than what we want, this part of the code will retrigger in this case, until %bytestoread is 0)
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         ;but $sockbr tells us how much we read, we decrease by that number,
 
         dec %bytestoread $sockbr
 
         dec %bytestoread $sockbr
 
       }
 
       }
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       else {
 
       else {
 
         var %a
 
         var %a
         sockread %a
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         ;skip empty line
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         ;when we start, the next line is the chunk size, but after reading a chunk, we must parse the $crlf ending that chunk
         while ($sockbr) && (%a == $null) { sockread %a }
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         ;if we read and %a is $null, we try to read the next line, if we can't find the next chunk in the current receive buffer, we return
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        sockread -f %a
 +
         while ($sockbr) && (%a == $null) { sockread -f %a }
 
         if (!$sockbr) || (%a == $null) return
 
         if (!$sockbr) || (%a == $null) return
 
         ;last chunk
 
         ;last chunk
 
         if (%a == 0) echo -a done
 
         if (%a == 0) echo -a done
 
         ;convert the hexadecimal number to decimal
 
         ;convert the hexadecimal number to decimal
         else { set %bytestoread $base(%a,16,10) }
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         else { set %bytestoread $base(%,16,10) }
 
       }
 
       }
 
     }
 
     }

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