This procedure is defined in the server but not documented via ad_proc or proc_doc and may be intended as a private interface.
The procedure is defined as:
proc unknown {args} {
variable ::tcl::UnknownPending
global auto_noexec auto_noload env tcl_interactive errorInfo errorCode
if {[info exists errorInfo]} {
set savedErrorInfo $errorInfo
}
if {[info exists errorCode]} {
set savedErrorCode $errorCode
}
set name [lindex $args 0]
if {![info exists auto_noload]} {
#
# Make sure we're not trying to load the same proc twice.
#
if {[info exists UnknownPending($name)]} {
return -code error "self-referential recursion in \"unknown\" for command \"$name\""
}
set UnknownPending($name) pending
set ret [catch {
auto_load $name [uplevel 1 {::namespace current}]
} msg opts]
unset UnknownPending($name)
if {$ret != 0} {
dict append opts -errorinfo "\n (autoloading \"$name\")"
return -options $opts $msg
}
if {![array size UnknownPending]} {
unset UnknownPending
}
if {$msg} {
if {[info exists savedErrorCode]} {
set ::errorCode $savedErrorCode
} else {
unset -nocomplain ::errorCode
}
if {[info exists savedErrorInfo]} {
set errorInfo $savedErrorInfo
} else {
unset -nocomplain errorInfo
}
set code [catch {uplevel 1 $args} msg opts]
if {$code == 1} {
#
# Compute stack trace contribution from the [uplevel].
# Note the dependence on how Tcl_AddErrorInfo, etc.
# construct the stack trace.
#
set errInfo [dict get $opts -errorinfo]
set errCode [dict get $opts -errorcode]
set cinfo $args
if {[string bytelength $cinfo] > 150} {
set cinfo [string range $cinfo 0 150]
while {[string bytelength $cinfo] > 150} {
set cinfo [string range $cinfo 0 end-1]
}
append cinfo ...
}
set tail "\n (\"uplevel\" body line 1)\n invoked from within\n\"uplevel 1 \$args\""
set expect "$msg\n while executing\n\"$cinfo\"$tail"
if {$errInfo eq $expect} {
#
# The stack has only the eval from the expanded command
# Do not generate any stack trace here.
#
dict unset opts -errorinfo
dict incr opts -level
return -options $opts $msg
}
#
# Stack trace is nested, trim off just the contribution
# from the extra "eval" of $args due to the "catch" above.
#
set last [string last $tail $errInfo]
if {$last + [string length $tail] != [string length $errInfo]} {
# Very likely cannot happen
return -options $opts $msg
}
set errInfo [string range $errInfo 0 $last-1]
set tail "\"$cinfo\""
set last [string last $tail $errInfo]
if {$last < 0 || $last + [string length $tail] != [string length $errInfo]} {
return -code error -errorcode $errCode -errorinfo $errInfo $msg
}
set errInfo [string range $errInfo 0 $last-1]
set tail "\n invoked from within\n"
set last [string last $tail $errInfo]
if {$last + [string length $tail] == [string length $errInfo]} {
return -code error -errorcode $errCode -errorinfo [string range $errInfo 0 $last-1] $msg
}
set tail "\n while executing\n"
set last [string last $tail $errInfo]
if {$last + [string length $tail] == [string length $errInfo]} {
return -code error -errorcode $errCode -errorinfo [string range $errInfo 0 $last-1] $msg
}
return -options $opts $msg
} else {
dict incr opts -level
return -options $opts $msg
}
}
}
if {([info level] == 1) && ([info script] eq "")
&& [info exists tcl_interactive] && $tcl_interactive} {
if {![info exists auto_noexec]} {
set new [auto_execok $name]
if {$new ne ""} {
set redir ""
if {[namespace which -command console] eq ""} {
set redir ">&@stdout <@stdin"
}
uplevel 1 [list ::catch [concat exec $redir $new [lrange $args 1 end]] ::tcl::UnknownResult ::tcl::UnknownOptions]
dict incr ::tcl::UnknownOptions -level
return -options $::tcl::UnknownOptions $::tcl::UnknownResult
}
}
if {$name eq "!!"} {
set newcmd [history event]
} elseif {[regexp {^!(.+)$} $name -> event]} {
set newcmd [history event $event]
} elseif {[regexp {^\^([^^]*)\^([^^]*)\^?$} $name -> old new]} {
set newcmd [history event -1]
catch {regsub -all -- $old $newcmd $new newcmd}
}
if {[info exists newcmd]} {
tclLog $newcmd
history change $newcmd 0
uplevel 1 [list ::catch $newcmd ::tcl::UnknownResult ::tcl::UnknownOptions]
dict incr ::tcl::UnknownOptions -level
return -options $::tcl::UnknownOptions $::tcl::UnknownResult
}
set ret [catch [list uplevel 1 [list info commands $name*]] candidates]
if {$name eq "::"} {
set name ""
}
if {$ret != 0} {
dict append opts -errorinfo "\n (expanding command prefix \"$name\" in unknown)"
return -options $opts $candidates
}
# Filter out bogus matches when $name contained
# a glob-special char [Bug 946952]
if {$name eq ""} {
# Handle empty $name separately due to strangeness
# in [string first] (See RFE 1243354)
set cmds $candidates
} else {
set cmds [list]
foreach x $candidates {
if {[string first $name $x] == 0} {
lappend cmds $x
}
}
}
if {[llength $cmds] == 1} {
uplevel 1 [list ::catch [lreplace $args 0 0 [lindex $cmds 0]] ::tcl::UnknownResult ::tcl::UnknownOptions]
dict incr ::tcl::UnknownOptions -level
return -options $::tcl::UnknownOptions $::tcl::UnknownResult
}
if {[llength $cmds]} {
return -code error "ambiguous command name \"$name\": [lsort $cmds]"
}
}
return -code error -errorcode [list TCL LOOKUP COMMAND $name] "invalid command name \"$name\""
}