Version 21 of Linux Console Text Editor In Pure TCL
Updated 2006-03-17 13:33:382004-06-16 SRIV This is a minimal console text editor for Linux written in pure TCL.
Usage: con-editor.tcl filename To save the file, press Ctrl-Q, it will prompt you to Save Y/n . Ctrl-Y will delete the current line.
If you use this from a minicom serial console in Linux, switch minicoms terminal type from VT102 to ANSI. I'm using this on a Gumstix with tclsh, since theres no more space left for any larger editor binary.
LV Perhaps the backspace key would work if you added a \u0008 (^h) to the current \u0007f (^?) case? (JH: Yes, added in)
Edited by JH 2005-05-04 to support any size terminal, clean up the code for improved readability, add real tab handling (tricky) and some other tidbits. Anyone wanting to interpret more escape codes should find it easier to work with.
Screenshot:
#!/bin/sh
# The next line is executed by /bin/sh, but not tcl \
exec tclsh "$0" ${1+"$@"}
# con-editor.tcl a linux console based editor in pure tcl
# 2004-06-16 Steve Redler IV
# 2005-05-04 mods by Hobbs to work in any terminal size, clean up code
# and add more key functionality, tab handling
# 2006-03-17 bugfix for cursor-left & for terms that report 0 cols & rows
set filename [lindex $argv 0]
proc edittext {fid} {
global BUFFER IDX
set viewRow 1 ; # row idx into view area, 1-based
set viewCol 1 ; # col idx into view area, 1-based
set bufRow 0 ; # row idx into full buffer, 0-based
set bufCol 0 ; # col idx into full buffer, 0-based
set IDX(ROWLAST) -1 ; # last row most recently displayed in view
set IDX(COLLAST) -1 ; # last col most recently displayed in view
set char "" ; # last char received
set line [lindex $BUFFER $bufRow] ; # line data of current line
display $bufRow $bufCol
home
while {$char != "\u0011"} {
set char [read $fid 1]
if {[eof $fid]} {return done}
# Control chars start at a == \u0001 and count up.
switch -exact -- $char {
\u0011 { # ^q - quit
return done
}
\u0001 { # ^a - beginning of line
set bufCol 0
}
\u0004 { # ^d - delete
if {$bufCol > [string length $line]} {
set bufCol [string length $line]
}
set line [string replace $line $bufCol $bufCol]
set BUFFER [lreplace $BUFFER $bufRow $bufRow $line]
set IDX(COLLAST) -1 ; # force redraw
}
\u0005 { # ^e - end of line
set bufCol [string length $line]
}
\u000a { # ^j - insert last yank
set currline [string range $line 0 [expr {$bufCol - 1}]]
set BUFFER [lreplace $BUFFER $bufRow $bufRow $currline]
incr bufRow
incr viewRow
set BUFFER [linsert $BUFFER $bufRow \
[string range $line $bufCol end]]
set IDX(COLLAST) -1 ; # force redraw
set line [lindex $BUFFER $bufRow]
set bufCol 0
}
\u0019 { # ^y - yank line
if {$bufRow < [llength $BUFFER]} {
set BUFFER [lreplace $BUFFER $bufRow $bufRow]
set IDX(COLLAST) -1 ; # force redraw
}
}
\u0008 -
\u007f { # ^h && backspace ?
if {$bufCol != 0} {
if {$bufCol > [string length $line]} {
set bufCol [string length $line]
}
incr bufCol -1
set line [string replace $line $bufCol $bufCol]
set BUFFER [lreplace $BUFFER $bufRow $bufRow $line]
set IDX(COLLAST) -1 ; # force redraw
}
}
\u001b { # ESC - handle escape sequences
set next [read $fid 1]
if {$next == "\["} { ; # \[
set next [read $fid 1]
switch -exact -- $next {
A { # Cursor Up (cuu1,up)
if {$bufRow > 0} {
incr bufRow -1
incr viewRow -1
}
}
B { # Cursor Down
if {$bufRow < [expr {[llength $BUFFER] - 1}]} {
incr bufRow 1
incr viewRow 1
}
}
C { # Cursor Right (cuf1,nd)
if {$bufCol < [string length $line]} {
incr bufCol 1
}
}
D { # Cursor Left
if {$bufCol > [string length $line]} {
set bufCol [string length $line]
}
if {$bufCol > 0} { incr bufCol -1 }
}
H { # Cursor Home
set bufCol 0
set bufRow 0
set viewRow 1
}
3 { # delete
set next [read $fid 1]
if {$bufCol > [string length $line]} {
set bufCol [string length $line]
}
set line [string replace $line $bufCol $bufCol]
set BUFFER [lreplace $BUFFER $bufRow $bufRow $line]
set IDX(COLLAST) -1 ; # force redraw
}
5 { # 5 Prev screen
if {[read $fid 1] == "~"} {
set size [expr {$IDX(ROWMAX) - 1}]
if {$bufRow < $size} {
set bufRow 0
set viewRow 1
} else {
incr bufRow -$size
incr viewRow -$size
}
}
}
6 { # 6 Next screen
if {[read $fid 1] == "~"} {
set size [expr {$IDX(ROWMAX) - 1}]
incr bufRow $size
incr viewRow $size
if {$bufRow >= [llength $BUFFER]} {
set viewRow [llength $BUFFER]
set bufRow [expr {$viewRow - 1}]
}
}
}
}
# most of the above cause a BUFFER row change
set line [lindex $BUFFER $bufRow]
}
}
default {
set line [string replace $line $bufCol $bufCol \
$char[string index $line $bufCol]]
set BUFFER [lreplace $BUFFER $bufRow $bufRow $line]
incr bufCol [string length $char]
if {$bufCol > [string length $line]} {
set bufCol [string length $line]
}
set IDX(COLLAST) -1 ; # force redraw
}
}
# Constrain current view idx
if {$viewRow <= 1} {set viewRow 1}
if {$viewRow >= ($IDX(ROWMAX) - 1)} {
set viewRow [expr {$IDX(ROWMAX) - 1}]
}
set viewCol [expr {$bufCol + 1}]
if {$viewCol >= $IDX(COLMAX)} {set viewCol $IDX(COLMAX)}
# start and end view area to display
set startRow [expr {$bufRow + 1 - $viewRow}]
set startCol [expr {$bufCol + 1 - $viewCol}]
display $startRow $startCol
# translate viewCol to proper index (account for tabs)
if {[string match "*\t*" $line]} {
# let's just brute force over the line
set i 0
foreach c [split [string range $line \
$startCol [expr {$bufCol - 1}]] ""] {
if {[string equal "\t" $c]} {
set i [expr {$i + (8 - $i%8)}] ; # align to 8c boundary
} else {
incr i
}
}
set viewCol [expr {$startCol + 1 + $i}]
}
idx [expr {$bufRow + 1}] $viewCol
puts -nonewline "\u001b\[${viewRow};${viewCol}H" ; # place cursor
cursor on
flush stdout
}
}
proc linerange {line start end} {
# Get # *visual* chars - account for tabs (== 8c) in line range
set line [string range $line $start $end]
if {[string match "*\t*" $line]} {
# let's just brute force over the line
set i 0
set end [expr {$end-$start}]
set res {}
foreach c [split $line ""] {
if {[string equal "\t" $c]} {
set i [expr {$i + (8 - $i%8)}] ; # align to 8c boundary
} else {
incr i
}
append res $c
if {$i > $end} { break }
}
return $res
}
return $line
}
proc display {startRow startCol} {
global IDX BUFFER
cursor off ; home
if {($IDX(ROWLAST) != $startRow) || ($IDX(COLLAST) != $startCol)} {
# Add display size to get end points
set endRow [expr {$startRow + $IDX(ROWMAX) - 1}]
set endCol [expr {$startCol + $IDX(COLMAX) - 1}]
for {set i $startRow} {$i < $endRow} {incr i} {
puts -nonewline "\u001b\[K" ; # erase current line
puts [linerange [lindex $BUFFER $i] $startCol $endCol]
}
set IDX(ROWLAST) $startRow
set IDX(COLLAST) $startCol
}
}
proc status {msg} {
global IDX
set len [expr {$IDX(ROWCOL) - 1}]
set str [format "%-${len}.${len}s" $msg]
puts -nonewline "\u001b\[$IDX(ROWMAX);00H$str"
}
proc idx {row col} {
global IDX
set str [format " L:%-4d C:%-4d" $row $col]
# the string must not exceed $IDX(ROWCOLLEN) length
puts -nonewline "\u001b\[$IDX(ROWMAX);$IDX(ROWCOL)H[string range \
$str 0 $IDX(ROWCOLLEN)]"
}
proc home {} { puts -nonewline "\u001b\[1;1H"; flush stdout }
proc clear {} { puts -nonewline "\u001b\[2J"; flush stdout }
proc cursor {bool} {
puts -nonewline "\u001b\[?[expr \
{$::IDX(ROWMAX)+1}][expr {$bool ? "h" : "j"}]"
flush stdout
}
#start of console editor program
#puts -nonewline $CLEAR
proc console_edit {fileName} {
global BUFFER IDX
#Script-Edit by Steve Redler IV [email protected] 5-30-2001
set IDX(ROWMAX) 24
set IDX(COLMAX) 80
if {![catch {exec stty -a} err]
&& [regexp {rows (\d+); columns (\d+)} $err -> rows cols]} {
if {$rows != "0" && $cols != 0} {
set IDX(ROWMAX) $rows
set IDX(COLMAX) $cols
}
}
set IDX(ROWCOLLEN) 15
set IDX(ROWCOL) [expr {$IDX(COLMAX) - $IDX(ROWCOLLEN)}]
set infile [open $fileName RDWR]
set BUFFER [split [read $infile] "\n"]
close $infile
clear ; home
status "\u0007$fileName loaded"
idx [llength $BUFFER] 1
fconfigure stdin -buffering none -blocking 1
fconfigure stdout -translation crlf
flush stdout
exec stty raw -echo
edittext stdin
status "Save '$fileName'? Y/n"
flush stdout
#fconfigure stdin -buffering full -blocking 1
set line [read stdin 1]
exec stty -raw echo
if {$line != "n"} {
set outfile [open $fileName w ]
puts "len of buffer [llength $BUFFER]"
for {set i 0} {$i<[llength $BUFFER]} {incr i} {
puts $outfile [lindex $BUFFER $i]
}
close $outfile
status " Saved"
} else {
status " Aborted"
}
after 100
clear ; home
exit 0
}
if {$filename == ""} {
puts "\nPlease specify a filename"
gets stdin filename
if {$filename == ""} {exit}
}
console_edit $filename