Eskil

    foreach dir $dirs {
        set dir [file normalize $dir]
        set files {}
        lappend files [file join $dir $plugin]
        lappend files [file join $dir $plugin.tcl]
        foreach file $files {
            if { ! [file exists   $file]} continue
            if { ! [file isfile   $file]} continue
            if { ! [file readable $file]} continue
            set ch [open $file r]
            set data [read $ch 20]
            close $ch
            if {[string match "##Eskil Plugin*" $data]} {
                set fSrc $file
                break
            }

    # Setup info
    $pi eval [list set ::WhoAmI [file rootname [file tail $src]]]
    $pi eval [list set ::WhoAmIFull [file normalize $src]]
    $pi eval [list set ::Info $info]
    interp share {} stdout $pi

    # Expose needed commands
    if { ! $allow} {
        interp expose $pi fconfigure ;# needed??
        interp hide $pi close
    }

    set pinfo {file 0 dir 0}
    dict set pinfo "allow" $allow
    if {[$pi eval info proc PreProcess] ne ""} {

        return
    }
    set ch [open $src]
    set lines [split [read $ch] \n]
    foreach line $lines {
        set lineT [string trim $line]
        if {$short} {
            if { ! [string match "#*" $lineT]} {
                break
            }
        }
        puts $line
    }
    close $ch
}

proc listPlugins {} {
    set dirs [PluginSearchPath]
    set result {}

    foreach dir $dirs {
        set dir [file normalize $dir]
        set files [glob -nocomplain [file join $dir *.tcl]]
        foreach file $files {
            set file [file normalize $file]
            if {[info exists done($file)]} continue
            if { ! [file exists $file]} continue
            if { ! [file isfile $file]} continue
            if { ! [file readable $file]} continue

            set done($file) 1
            set ch [open $file r]
            set data [read $ch 200]
            if {[regexp {^\#\#Eskil Plugin :(.*?)(\n|$)} $data -> descr]} {
                set root [file rootname [file tail $file]]
                dict set result $root "descr" $descr

    }

    disallowEdit $top
    set in1 $::eskil($top,leftFile)
    set in2 $::eskil($top,rightFile)

    foreach item [lsort -dictionary [array names ::eskil $top,pluginname,*]] {
        set pI [lindex [split $item ","] end]

        set allow [dict get $::eskil($top,pluginpinfo,$pI) allow]
        # Pass ::argv to plugin
        set pArgv $::eskil(argv)
        if {[info exists ::eskil($top,pluginargv,$pI)]} {
            lappend pArgv {*}$::eskil($top,pluginargv,$pI)
        }
        $::eskil($top,plugin,$pI) eval [list set ::argv $pArgv]
        # Pass ::Pref to plugin
        $::eskil($top,plugin,$pI) eval [list array set ::Pref [array get ::Pref]]
        # Pass File info to plugin
        $::eskil($top,plugin,$pI) eval [list set ::File(left)  $::eskil($top,leftFile)]
        $::eskil($top,plugin,$pI) eval [list set ::File(right) $::eskil($top,rightFile)]

        set out1 [tmpFile]
        set out2 [tmpFile]

        set chi [open $in1 r]
        set cho [open $out1 w]
        set chi2 [open $in2 r]
        set cho2 [open $out2 w]
        interp share {} $chi $::eskil($top,plugin,$pI)
        interp share {} $cho $::eskil($top,plugin,$pI)
        interp share {} $chi2 $::eskil($top,plugin,$pI)
        interp share {} $cho2 $::eskil($top,plugin,$pI)

        set cmd1 [list PreProcess left $chi $cho]
        set cmd2 [list PreProcess right $chi2 $cho2]
        if {[info commands yield] ne ""} {
            # When in 8.6, this is done in coroutines allowing each call
            # to yield and to alternate between them until done
            set c1 __plugin_cr1$top
            set c2 __plugin_cr2$top
            set cmd1 [linsert $cmd1 0 coroutine $c1]
            set cmd2 [linsert $cmd2 0 coroutine $c2]
            set usenew1 [$::eskil($top,plugin,$pI) eval $cmd1]
            set usenew2 [$::eskil($top,plugin,$pI) eval $cmd2]
            interp alias {} pnw $::eskil($top,plugin,$pI) namespace which
            while {[pnw $c1] ne {} || [pnw $c2] ne {}} {
                if {[pnw $c1] ne {}} {
                    set usenew1 [$::eskil($top,plugin,$pI) eval $c1]
                }
                if {[pnw $c2] ne {}} {
                    set usenew2 [$::eskil($top,plugin,$pI) eval $c2]
                }
            }
        } else {
            set usenew1 [$::eskil($top,plugin,$pI) eval $cmd1]
            set usenew2 [$::eskil($top,plugin,$pI) eval $cmd2]
        }

        if {$allow} {
            $::eskil($top,plugin,$pI) eval close $chi
            $::eskil($top,plugin,$pI) eval close $cho
            $::eskil($top,plugin,$pI) eval close $chi2
            $::eskil($top,plugin,$pI) eval close $cho2
        } else {
            $::eskil($top,plugin,$pI) invokehidden close $chi
            $::eskil($top,plugin,$pI) invokehidden close $cho
            $::eskil($top,plugin,$pI) invokehidden close $chi2
            $::eskil($top,plugin,$pI) invokehidden close $cho2
        }
        close $chi
        close $cho
        close $chi2
        close $cho2

        if {$usenew1} {
            # The file after processing should be used both
            # for comparison and for displaying.
            if { ! [info exists ::eskil($top,leftFileBak)]} {
                set ::eskil($top,leftFileBak) $::eskil($top,leftFile)
            }
            unset -nocomplain ::eskil($top,leftFileDiff)
            set ::eskil($top,leftFile) $out1
        } else {
            set ::eskil($top,leftFileDiff) $out1
        }
        if {$usenew2} {
            if { ! [info exists ::eskil($top,rightFileBak)]} {
                set ::eskil($top,rightFileBak) $::eskil($top,rightFile)
            }
            unset -nocomplain ::eskil($top,rightFileDiff)
            set ::eskil($top,rightFile) $out2
        } else {
            set ::eskil($top,rightFileDiff) $out2
        }

    incr pos -1
    $wt insert $pos $win
}

# Add a tab to plugin prefernces
proc EditPrefPluginsAddTab {top dirdiff {pos {}}} {
    set wt $top.prefplugin.tab
    set pI [$wt index end]
    if {$pos eq "" || $pos >= ($pI - 1)} {
        # Since the "+" tab is last, the index is n for any new one
        set pos [expr {$pI - 1}]
    }
    ttk::frame $wt.f,$pI
    $wt insert $pos $wt.f,$pI -text "Plugin"

    set wt $wt.f,$pI

    set plugins [listPlugins]
    if {[llength $plugins] == 0} {
        grid [ttk::label $wt.l -text "No plugins found."] - -padx 3 -pady 3
    }
    if { ! [info exists ::eskil($top,pluginname,$pI)]} {
        set ::eskil($top,pluginname,$pI) ""
    }
    if { ! [info exists ::eskil($top,plugininfo,$pI)]} {
        set ::eskil($top,plugininfo,$pI) ""
    }
    if { ! [info exists ::eskil($top,pluginallow,$pI)]} {
        set ::eskil($top,pluginallow,$pI) 0
    }
    set ::eskil($top,edit,pluginname,$pI) $::eskil($top,pluginname,$pI)
    set ::eskil($top,edit,plugininfo,$pI) $::eskil($top,plugininfo,$pI)
    set ::eskil($top,edit,pluginallow,$pI) $::eskil($top,pluginallow,$pI)

    ttk::labelframe $wt.lfs -text "Select"
    grid columnconfigure $wt.lfs 1 -weight 1

    set t 0
    foreach {plugin info} $plugins {
        set descr [dict get $info descr]
        if {$dirdiff && ![dict get $info dir]} continue
        ttk::radiobutton $wt.rb$t -variable ::eskil($top,edit,pluginname,$pI) \
                -value $plugin -text $plugin
        ttk::label $wt.l$t -text $descr -anchor w
        grid $wt.rb$t $wt.l$t -in $wt.lfs -sticky we -padx 3 -pady 3
        incr t
    }
    ttk::radiobutton $wt.rb$t -variable ::eskil($top,edit,pluginname,$pI) \
            -value "" -text "No Plugin"
    ttk::button $wt.bs -text "Show" \
            -command "ShowPlugin $wt \$::eskil($top,edit,pluginname,$pI)"
    addBalloon $wt.bs "Show plugin source code."
    grid $wt.rb$t $wt.bs -in $wt.lfs -sticky we -padx 3 -pady 3
    grid $wt.bs -sticky e

    ttk::labelframe $wt.lfgc -text "Generic Configuration"
    grid columnconfigure $wt.lfgc 1 -weight 1

    ttk::label $wt.li -text "Info" -anchor w
    addBalloon $wt.li "Info passed to plugin. Plugin specific."
    ttk::entry $wt.ei -textvariable ::eskil($top,edit,plugininfo,$pI)
    grid $wt.li $wt.ei -in $wt.lfgc -sticky we -padx 3 -pady 3

    ttk::checkbutton $wt.cb -text "Privilege" \
            -variable ::eskil($top,edit,pluginallow,$pI)
    addBalloon $wt.cb "Run plugin with raised privileges"
    grid $wt.cb -  -in $wt.lfgc -sticky w -padx 3 -pady 3

    ttk::labelframe $wt.lfsc -text "Specific Configuration"
    set ::widgets($top,prefPluginsSpec,$pI) $wt.lfsc
    trace add variable ::eskil($top,edit,pluginname,$pI) write \
            [list UpdateSpecificPluginConf $top $pI]
    UpdateSpecificPluginConf $top $pI

    grid $wt.lfs  -sticky we -padx 3 -pady 3
    grid $wt.lfgc -sticky we -padx 3 -pady 3
    grid $wt.lfsc -sticky we -padx 3 -pady 3
    grid columnconfigure $wt 0 -weight 1
}

# When a new plugin is selected, update the list of specific options.
# "args" is needed to swallow the extra variable trace args.
proc UpdateSpecificPluginConf {top pI args} {
    set w $::widgets($top,prefPluginsSpec,$pI)
    # If the dialog is closed w might not exist
    if { ! [winfo exists $w]} return
    eval destroy [winfo children $w]

    set arg $::eskil($top,edit,pluginname,$pI)
    set pOpts {}
    if {$arg ne ""} {
        set res [LocatePlugin $arg]
        set pOpts [dict get $res opts]
    }
    # Look for defaults on the command line
    set pArgv $::eskil(argv)
    if {[info exists ::eskil($top,pluginargv,$pI)]} {
        lappend pArgv {*}$::eskil($top,pluginargv,$pI)
    }
    # Look for declarations of command line options
    set t 0
    set ::eskil($top,edit,opts,$pI) $pOpts
    foreach {name flag doc} $pOpts {
        ttk::label $w.l$t -text $name
        addBalloon $w.l$t -fmt $doc
        grid $w.l$t -sticky "w" -padx 3 -pady 3
        if {$flag} {
            # Initialise if given.
            if {[lsearch -exact $pArgv $name] >= 0} {
                set ::eskil($top,edit,$name,$pI) 1
                # Move responsibility from global argv
                set ix [lsearch -exact $::eskil(argv) $name]
                if {$ix >= 0} {
                    set ::eskil(argv) [lreplace $::eskil(argv) $ix $ix]
                    lappend ::eskil($top,pluginargv,$pI) $name
                }
            }
            ttk::checkbutton $w.s$t -text "On" \
                    -variable ::eskil($top,edit,$name,$pI)
            grid $w.s$t -row $t -column 1 -sticky "w" -padx 3 -pady 3
        } else {
            # Initialise if given.
            set ix [lsearch -exact $pArgv $name]
            if {$ix >= 0} {
                set ::eskil($top,edit,$name,$pI) [lindex $pArgv $ix+1]
                # Move responsibility from global argv
                set ix [lsearch -exact $::eskil(argv) $name]
                if {$ix >= 0} {
                    lappend ::eskil($top,pluginargv,$pI) $name \
                            [lindex $::eskil(argv) $ix+1]
                    set ::eskil(argv) [lreplace $::eskil(argv) $ix $ix+1]
                }
            }
            ttk::entry $w.s$t \
                    -textvariable ::eskil($top,edit,$name,$pI)
            grid $w.s$t -row $t -column 1 -sticky we -padx 3 -pady 3
        }
        incr t
    }
    grid columnconfigure $w 1 -weight 1
    if {$t == 0} {
        ttk::label $w.l -text "No specific configuration"
        grid $w.l -sticky "w" -padx 3 -pady 3
        return
    }
}

# Ok or Apply pressend in Plugin Preference
proc EditPrefPluginsOk {top wt apply} {
    # Compress plugin info in tab order
    set allN {}
    foreach win [$wt.tab tabs] {
        set pI [lindex [split $win ","] end]
        if { ! [string is integer -strict $pI]} continue
        # Find all used.
        if {$::eskil($top,edit,pluginname,$pI) ne ""} {
            lappend allN $pI
        }
    }
    if {[llength $allN] == 0} {
        lappend allN 1
    }

    # Keep the dialog if we are only applying
    if { ! $apply} {
        destroy $wt
    }

    # Transfer them to consecutive numbers
    set t 1
    foreach pI $allN {
        set ::eskil($top,pluginname,$t)  $::eskil($top,edit,pluginname,$pI)
        set ::eskil($top,plugininfo,$t)  $::eskil($top,edit,plugininfo,$pI)
        set ::eskil($top,pluginallow,$t) $::eskil($top,edit,pluginallow,$pI)
        incr t
    }
    # Remove any old
    foreach item [array names ::eskil $top,pluginname,*] {
        set pI [lindex [split $item ","] end]
        if {$pI >= $t} {
            unset ::eskil($top,pluginname,$pI)
            set ::eskil($top,plugininfo,$pI) ""
            set ::eskil($top,pluginallow,$pI) 0
        }
    }

    # Handle all plugins
    foreach item [array names ::eskil $top,pluginname,*] {
        set pI [lindex [split $item ","] end]
        if {$::eskil($top,pluginname,$pI) ne ""} {
            set pinterp [createPluginInterp $::eskil($top,pluginname,$pI) \
                                 $::eskil($top,plugininfo,$pI) \
                                 $::eskil($top,pluginallow,$pI) pinfo]
        } else {
            set pinterp ""
            set pinfo ""
        }
        set ::eskil($top,plugin,$pI) $pinterp
        set ::eskil($top,pluginpinfo,$pI) $pinfo
        set ::eskil($top,pluginargv,$pI) {}
        foreach {name flag doc} $::eskil($top,edit,opts,$pI) {
            if {$flag} {
                if {[info exists ::eskil($top,edit,$name,$pI)] && \
                            $::eskil($top,edit,$name,$pI)} {
                    lappend ::eskil($top,pluginargv,$pI) $name
                }
            } else {
                if {[info exists ::eskil($top,edit,$name,$pI)] && \
                            $::eskil($top,edit,$name,$pI) ne ""} {
                    lappend ::eskil($top,pluginargv,$pI) $name \
                            $::eskil($top,edit,$name,$pI)
                }
            }
        }
    }
}

# Put Tcl code in a text widget, with some syntax highlighting
proc TextViewTcl {tW data} {
    $tW tag configure comment -foreground "#b22222"
    foreach line [split $data \n] {
        if {[regexp {^\s*#} $line]} {
            $tW insert end $line\n comment
        } elseif {[regexp {^(.*;\s*)(#.*)$} $line -> pre post]} {
            $tW insert end $pre
            $tW insert end $post\n comment
        } else {
            $tW insert end $line\n
        }
    }
}

# Show plugin source
proc ShowPlugin {parent plugin} {
    set res [LocatePlugin $plugin]