fblocked - able input
fblocked channelId
fblocked(1t) Tcl Built-In Commands fblocked(1t) NAME fblocked - Test whether the last input operation exhausted all avail- able input SYNOPSIS fblocked channelId DESCRIPTION The fblocked command returns 1 if the most recent input operation on channelId returned less information than requested because all avail- able input was exhausted. For example, if gets is invoked when there are only three characters available for input and no end-of-line sequence, gets returns an empty string and a subsequent call to fblocked will return 1. ChannelId must be an identifier for an open channel such as a Tcl stan- dard channel (stdin, stdout, or stderr), the return value from an invo- cation of open or socket, or the result of a channel creation command provided by a Tcl extension. EXAMPLE The fblocked command is particularly useful when writing network servers, as it allows you to write your code in a line-by-line style without preventing the servicing of other connections. This can be seen in this simple echo-service: # This is called whenever a new client connects to the server proc con- nect {chan host port} { set clientName [format <%s:%d> $host $port] puts "connection from $clientName" fconfigure $chan -blocking 0 -buffering line fileevent $chan readable [list echoLine $chan $clientName] } # This is called whenever either at least one byte of input # data is available, or the channel was closed by the client. proc echoLine {chan clientName} { gets $chan line if {[eof $chan]} { puts "finishing connection from $clientName" close $chan } elseif {![fblocked $chan]} { # Didn't block waiting for end-of-line puts "$clientName - $line" puts $chan $line } } # Create the server socket and enter the event-loop to wait # for incoming connections... socket -server connect 12345 vwait forever ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+------------------+ |Availability | runtime/tcl-8 | +---------------+------------------+ |Stability | Uncommitted | +---------------+------------------+ SEE ALSO gets(n), open(n), read(n), socket(n), Tcl_StandardChannels(3) KEYWORDS blocking, nonblocking NOTES Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from http://prdownloads.sourceforge.net/tcl/tcl- core8.6.7-src.tar.gz. Further information about this software can be found on the open source community website at https://www.tcl.tk/. Tcl 7.5 fblocked(1t)