Eskil

proc displayPatch {top} {
    global Pref

    set ::diff($top,leftLabel) "Patch $::diff($top,patchFile): old"
    set ::diff($top,rightLabel) "Patch $::diff($top,patchFile): new"
    update idletasks

    if {$::diff($top,patchFile) eq "-"} {
        set ch stdin
    } else {
        set ch [open $::diff($top,patchFile) r]
    }

    set style ""
    set divider "-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-"

    set leftLine 1
    set rightLine 1
    set leftLines {}

            continue
        }
    }
    if {$state != "none"} {
        displayOnePatch $top $leftLines $rightLines $leftLine $rightLine
    }

    if {$ch ne "stdin"} {
        close $ch
    }
}

#####################################
# Main diff
#####################################

# Prepare for a diff by creating needed temporary files

proc FileIsDirectory {file {kitcheck 0}} {
    # Skip directories
    if {[file isdirectory $file]} {return 1}

    # This detects .kit but how to detect starpacks?
    if {[file extension $file] eq ".kit" | $kitcheck} {
        if {![catch {package require vfs::mk4}]} {
            if {![catch {vfs::mk4::Mount $file $file -readonly}]} {
                # Check for contents to ensure it is a kit
                if {[llength [glob -nocomplain $file/*]] == 0} {
                    vfs::unmount $file
                }
            }
        }
    }
    return [file isdirectory $file]
}

# A wrapper for tk_getOpenFile

  -nodiff     : Normally, if there are enough information on the
                command line to run diff, Eskil will do so unless
                this option is specified.
  -dir        : Start in directory diff mode. Ignores other args.
  -clip       : Start in clip diff mode. Ignores other args.
  -patch      : View patch file.
  -           : Read patch file from standard input, to allow pipes.
  -context <n>: Show only differences, with <n> lines of context.
  -foreach    : Open one diff window per file listed.
  -close      : Close windows with no changes.

  -noparse    : Eskil can perform analysis of changed blocks to
  -line       : improve display. See online help for details.
  -smallblock : The default. Do block analysis on small blocks.

            }
        } elseif {$arg eq "-o"} {
            set nextArg mergeFile
        } elseif {$arg eq "-r"} {
            set nextArg revision
        } elseif {$arg eq "-debug"} {
            set ::debug 1
        } elseif {$arg eq "-"} {
            # Allow "-" for stdin patch processing
            lappend files "-"
        } else {
            set apa [file normalize [file join [pwd] $arg]]
            if {![file exists $apa]} {
                puts "Bad argument: $arg"
                exit
            } else {
                lappend files $apa

    if {$len == 0 && $dodir} {
        set dirdiff(leftDir) [pwd]
        set dirdiff(rightDir) [pwd]
        makeDirDiffWin
        return
    }
    if {$len == 1} {
        set fullname [lindex $files 0]
        if {[FileIsDirectory $fullname 1]} {
            set dirdiff(leftDir) $fullname
            set dirdiff(rightDir) $dirdiff(leftDir)
            makeDirDiffWin
            return
        }
    } elseif {$len >= 2} {
        set fullname1 [lindex $files 0]
        set fullname2 [lindex $files 1]
        if {[FileIsDirectory $fullname1 1] && [FileIsDirectory $fullname2 1]} {
            set dirdiff(leftDir) $fullname1
            set dirdiff(rightDir) $fullname2
            makeDirDiffWin
            after idle doDirCompare
            return
        }

                foreach {item val} [array get opts] {
                    set ::diff($top,$item) $val
                }
                # It is preferable to see the end if the rev string is too long
                $::widgets($top,rev1) xview end
                $::widgets($top,rev2) xview end
            }
            set fullname $file
            set fulldir [file dirname $fullname]
            if {$::diff($top,mode) eq "conflict"} {
                startConflictDiff $top $fullname
                after idle [list doDiff $top]
                set ReturnAfterLoop 1
                continue
            }

                }
            }
            # No revision control. Is it a patch file?
            set ::diff($top,leftDir) $fulldir
            set ::diff($top,leftFile) $fullname
            set ::diff($top,leftLabel) $fullname
            set ::diff($top,leftOK) 1
            if {$dopatch                                 || \
                    [regexp {\.(diff|patch)$} $fullname] || \
                    $fullname eq "-"} {
                set ::diff($top,mode) "patch"
                set ::diff($top,patchFile) $fullname
                set autobrowse 0
                if {$noautodiff} {
                    enableRedo $top
                } else {
                    after idle [list doDiff $top]