slebetman: Here's my first attempt at a pure-tcl implementation of readline-like capabilities. Save this into a file tclline.tcl and source it from an interactive tclsh.
The good news is that console programs like vi and links and even the Linux Console Text Editor In Pure TCL works perfectly with this. The less than good news is that colors somehow don't work automatically. They work, just not on by default. Maybe something to do with environment variables.
If you are brave enough with it you can even source it from your .tclshrc file.
ak: Note that the 'exec stty ...' is unix specific. It is also the one part we cannot do in pure Tcl. It is either the exec, or a C extension (like Expect (I think Expect can do the same changes to the pty stty is able of. IIRC)). Regarding colors, the terminal should be ANSI compatible. Like xterm. Needs TERM=xterm for this. See also the new 'term' module of tcllib, which contains symbolic names/commands for lots of the command sequences recognized by an ansi terminal.
slebetman: Quite true ;) I guess this really should be called Unix/Linux Readline in Pure Tcl. Actually, stty is not the only dependency. This also assumes a VT100/xterm/linux terminal. The escape sequences won't work things like the COMSPEC shell or even Tkcon.
slebetman 14 Jul 2006: Implemented proper (not so buggy) word completion. Word completion first searches the filesystem, then falls back to tcl commands & procs and finally to (global?) variables. Implemented the alias and unalias commands. I needed them to support coloring in ls and vi (so I can do: alias ls {ls --color=auto}). Also made history persistent by saving to a .tclline_history file and implemented a .tcllinerc file. The only remaining major features that's not yet implemented are long line editing and multi-line editing.
slebetman: New version. This now properly supports long line editing. Word completion now colours hints: commands are green, variables magenta everything else not coloured. I've also implemented "universal" command substitution which substitutes not only Tcl commands and procs but also substitutes executables via exec. So now you can do things like: set x [split [cat /etc/mtab] \n]. Multi-line editing is still not implemented.
#! /usr/bin/env tclsh
# tclline: An attempt at a pure tcl readline.
# Initialise our own env variables:
foreach {var val} {
PROMPT ">"
HISTORY ""
HISTORY_BUFFER 100
COMPLETION_MATCH ""
} {
if {![info exists env($var)]} {
set env($var) $val
}
}
foreach {var val} {
CMDLINE ""
CMDLINE_CURSOR 0
CMDLINE_LINES 0
HISTORY_LEVEL -1
} {
set env($var) $val
}
array set ALIASES {}
# Initialise HISTORY if available:
set HISTFILE $env(HOME)/.tclline_history
set RCFILE $env(HOME)/.tcllinerc
if {[llength $env(HISTORY)] == 0} {
if {[file exists $HISTFILE]} {
set f [open $HISTFILE r]
set env(HISTORY) [split [read $f] "\n"]
close $f
}
}
proc ESC {} {
return "\033"
}
proc shift {ls} {
upvar 1 $ls LIST
set ret [lindex $LIST 0]
set LIST [lrange $LIST 1 end]
return $ret
}
proc readbuf {txt} {
upvar 1 $txt STRING
set ret [string index $STRING 0]
set STRING [string range $STRING 1 end]
if {$STRING == ""} {
append STRING [read stdin]
}
return $ret
}
proc goto {row {col 1}} {
switch -- $row {
"home" {set row 1}
}
print "[ESC]\[${row};${col}H" nowait
}
proc gotocol {col} {
print "\r[ESC]\[${col}C" nowait
}
proc clear {} {
print "[ESC]\[2J" nowait
goto home
}
proc clearline {} {
print "[ESC]\[2K\r" nowait
}
proc getColumns {} {
set cols 0
if {![catch {exec stty -a} err]} {
regexp {rows \d+; columns (\d+)} $err -> cols
}
return $cols
}
proc prompt {{txt ""}} {
global env
set env(COLUMNS) [getColumns]
set prompt [subst $env(PROMPT)]
set txt "$prompt$txt"
set len [string length $txt]
foreach {end mid} $env(CMDLINE_LINES) break
# Calculate how many extra lines we need to display:
set n [expr {int(ceil(double($len)/$env(COLUMNS)))-1}]
# Reserve spaces for display:
if {$end} {
if {$mid} {
print "[ESC]\[${mid}B" nowait
}
for {set x 0} {$x < $end} {incr x} {
clearline
print "[ESC]\[1A" nowait
}
}
clearline
set env(CMDLINE_LINES) $n
# Output line(s):
print "\r$txt"
# Set cursor position:
set len [expr {$env(CMDLINE_CURSOR)+[string length $prompt]}]
set col [expr {$len % $env(COLUMNS)}]
set n [expr {$n-($len / $env(COLUMNS))}]
if {$n <= 0} {
if {$col == 0} {
set col [expr {$env(COLUMNS)-1}]
}
set n 0
} elseif {$n} {
print "[ESC]\[${n}A" nowait
}
gotocol $col
lappend env(CMDLINE_LINES) $n
}
proc print {txt {wait wait}} {
# Sends output to stdout chunks at a time.
# This is to prevent the terminal from
# hanging if we output too much:
while {[string length $txt]} {
puts -nonewline [string range $txt 0 2047]
set txt [string range $txt 2048 end]
if {$wait == "wait"} {
after 1
}
}
}
rename unknown _unknown
proc unknown {args} {
global env
set name [lindex $args 0]
set cmdline $env(CMDLINE)
set cmd [string trim [regexp -inline {^\s*\w+} $cmdline]]
set new [auto_execok $name]
if {[string compare {} $new]} {
set redir ""
if {$name == $cmd && [info command $cmd] == ""} {
set redir ">&@ stdout <@ stdin"
}
return [uplevel 1 exec $redir $new [lrange $args 1 end]]
}
eval _unknown $args
}
proc alias {word command} {
global ALIASES
set ALIASES($word) $command
}
proc unalias {word} {
global ALIASES
array unset ALIASES $word
}
################################
# Key bindings
################################
proc handleEscapes {} {
global env
upvar 1 keybuffer keybuffer
set seq ""
set found 0
while {[set ch [readbuf keybuffer]] != ""} {
append seq $ch
switch -exact -- $seq {
"\[A" { ;# Cursor Up (cuu1,up)
handleHistory 1
set found 1; break
}
"\[B" { ;# Cursor Down
handleHistory -1
set found 1; break
}
"\[C" { ;# Cursor Right (cuf1,nd)
if {$env(CMDLINE_CURSOR) < [string length $env(CMDLINE)]} {
incr env(CMDLINE_CURSOR)
}
set found 1; break
}
"\[D" { ;# Cursor Left
if {$env(CMDLINE_CURSOR) > 0} {
incr env(CMDLINE_CURSOR) -1
}
set found 1; break
}
"\[H" -
"\[7~" -
"\[1~" { ;# home
set env(CMDLINE_CURSOR) 0
set found 1; break
}
"\[3~" { ;# delete
if {$env(CMDLINE_CURSOR) < [string length $env(CMDLINE)]} {
set env(CMDLINE) [string replace $env(CMDLINE) \
$env(CMDLINE_CURSOR) $env(CMDLINE_CURSOR)]
}
set found 1; break
}
"\[F" -
"\[K" -
"\[8~" -
"\[4~" { ;# end
set env(CMDLINE_CURSOR) [string length $env(CMDLINE)]
set found 1; break
}
"\[5~" { ;# Page Up }
"\[6~" { ;# Page Down }
}
}
return $found
}
proc handleControls {} {
global env
upvar 1 char char
upvar 1 keybuffer keybuffer
# Control chars start at a == \u0001 and count up.
switch -exact -- $char {
\u0003 { ;# ^c
# doExit
}
\u0008 -
\u007f { ;# ^h && backspace ?
if {$env(CMDLINE_CURSOR) > 0} {
incr env(CMDLINE_CURSOR) -1
set env(CMDLINE) [string replace $env(CMDLINE) \
$env(CMDLINE_CURSOR) $env(CMDLINE_CURSOR)]
prompt $env(CMDLINE)
}
}
\u001b { ;# ESC - handle escape sequences
if {[handleEscapes]} {
prompt $env(CMDLINE)
}
}
}
# Rate limiter:
set keybuffer ""
}
proc shortMatch {maybe} {
# Find the shortest matching substring:
set maybe [lsort $maybe]
set shortest [lindex $maybe 0]
foreach x $maybe {
while {![string match $shortest* $x]} {
set shortest [string range $shortest 0 end-1]
}
}
return $shortest
}
proc handleCompletion {} {
global env
set vars ""
set cmds ""
set execs ""
set files ""
# First find out what kind of word we need to complete:
set wordstart [string last " " $env(CMDLINE)]
incr wordstart
set word [string range $env(CMDLINE) $wordstart end]
if {[string trim $word] == ""} return
# Check if word is a variable:
if {[string index $word 0] == "\$"} {
foreach x [uplevel #0 {info vars}] {
set x "\$$x"
if {[string match $word* $x]} {
lappend vars $x
}
}
} else {
# Check if word is possibly a path:
if {[string index $word 0] == "/" ||
[string index $word 0] == "." ||
$wordstart != 0
} {
set files [glob -nocomplain $word*]
}
if {$files == ""} {
# Not a path then get all possibilities:
if {$wordstart == 0} {
# Check executables:
foreach dir [split $env(PATH) :] {
foreach f [glob -nocomplain -directory $dir $word*] {
lappend execs [string trimleft \
[string range $f \
[string length $dir] end] "/"]
}
}
} else {
# Check variables anyway:
foreach x [uplevel #0 {info vars}] {
if {[string match $word* $x]} {
lappend vars $x
}
}
}
# Check commands:
foreach x [info commands] {
if {[string match $word* $x]} {
lappend cmds $x
}
}
}
}
set maybe [concat $vars $cmds $execs $files]
set shortest [shortMatch $maybe]
if {"$word" == "$shortest"} {
if {[llength $maybe] > 1 && $env(COMPLETION_MATCH) != $maybe} {
clearline
set temp ""
foreach {match format} {
vars "35"
cmds "32"
execs "32"
files "0"
} {
if {[llength $match]} {
append temp "[ESC]\[${format}m"
foreach x [set $match] {
append temp "[file tail $x] "
}
append temp "[ESC]\[0m"
}
}
print "\n$temp\n"
}
set env(COMPLETION_MATCH) $maybe
} else {
if {[file isdirectory $shortest] &&
[string index $shortest end] != "/"} {
append shortest "/"
}
if {$shortest != ""} {
set env(CMDLINE) \
[string replace $env(CMDLINE) $wordstart end $shortest]
} else {
print "\nNo match found.\n"
}
}
set env(CMDLINE_CURSOR) [string length $env(CMDLINE)]
prompt $env(CMDLINE)
}
proc handleHistory {x} {
global env
set hlen [llength $env(HISTORY)]
incr env(HISTORY_LEVEL) $x
if {$env(HISTORY_LEVEL) > -1} {
set env(CMDLINE) [lindex $env(HISTORY) end-$env(HISTORY_LEVEL)]
set env(CMDLINE_CURSOR) [string length $env(CMDLINE)]
prompt $env(CMDLINE)
}
if {$env(HISTORY_LEVEL) <= -1} {
set env(HISTORY_LEVEL) -1
set env(CMDLINE) ""
set env(CMDLINE_CURSOR) 0
prompt ""
} elseif {$env(HISTORY_LEVEL) > $hlen} {
set env(HISTORY_LEVEL) $hlen
}
}
################################
# main()
################################
proc rawInput {} {
fconfigure stdin -buffering none -blocking 0
fconfigure stdout -buffering none -translation crlf
exec stty raw -echo
}
proc lineInput {} {
exec stty -raw echo
}
proc doExit {{code 0}} {
global env HISTFILE
# Reset terminal:
print "[ESC]c[ESC]\[2J" nowait
lineInput
if {[llength $env(HISTORY)] > 0} {
set f [open $HISTFILE w]
puts -nonewline $f [join $env(HISTORY) "\n"]
close $f
}
exit $code
}
if {[file exists $RCFILE]} {
source $RCFILE
}
rawInput
prompt
# This is to restore the environment on exit:
# Do not unalias this!
alias exit doExit
proc tclline {} {
global env
set char ""
set keybuffer ""
while {1} {
append keybuffer [read stdin]
if {[eof stdin]} return
set char [readbuf keybuffer]
if {$char == ""} {
# Sleep for a bit to reduce CPU time:
after 40
continue
}
if {[string is print $char]} {
set x $env(CMDLINE_CURSOR)
if {$x < 1 && [string trim $char] == ""} continue
set trailing [string range $env(CMDLINE) $x end]
set env(CMDLINE) [string replace $env(CMDLINE) $x end]
append env(CMDLINE) $char
append env(CMDLINE) $trailing
incr env(CMDLINE_CURSOR)
if {$keybuffer == ""} {
prompt $env(CMDLINE)
}
} elseif {$char == "\t"} {
handleCompletion
} elseif {$char == "\n" || $char == "\r"} {
after 1 {
global env ALIASES
print "\n" nowait
# Handle aliases:
set cmdline $env(CMDLINE)
set cmd [string trim [regexp -inline {^\s*\w+} $cmdline]]
if {[info exists ALIASES($cmd)]} {
regsub -- "(?q)$cmd" $cmdline $ALIASES($cmd) cmdline
}
# Run the command:
catch $cmdline res
print "$res\n"
# Append HISTORY:
set env(HISTORY_LEVEL) -1
set old [lsearch -exact $env(HISTORY) $env(CMDLINE)]
if {$old != -1} {
set env(HISTORY) [lreplace $env(HISTORY) $old $old]
}
lappend env(HISTORY) $env(CMDLINE)
set env(HISTORY) \
[lrange $env(HISTORY) end-$env(HISTORY_BUFFER) end]
set env(CMDLINE) ""
set env(CMDLINE_CURSOR) 0
rawInput
prompt
after 1 tclline
}
lineInput
return
} else {
handleControls
}
}
}
tclline
vwait forever
doExitto have tclline automatically available when you start tclsh add the following to your .tclshrc file:
if {$tcl_interactive} {
source /path/to/your/tclline.tcl
}rdt Nice idea, but my question is: Is the if test really necessary? Isn't .tclshrc only read when tclsh is running interactively? Next question: How about adding this into the interactive part of init.tcl ?
rdt Another question: I can't really see what you changed in the unknown proc as I have 8.4 and tkdiff on the two procs shows a lot of change in the 8.4 version. So what did you change/add to that proc for your version?
slebetman: Only one simple thing: I removed the [info level] and [info script] test to allow unknown to call auto_execok from any level after the shell sources tclline. Try running the commands below in an interactive session of tclsh and see if the output makes sense. If it does, that's probably the only editing you need:
set x [info body unknown]
set x [regsub -all {if \{.{0,5}info level.{0,10}?&&} $x "if {"]
set x [regsub -all {if \{.{0,5}info script.{0,10}?&&} $x "if {"]
set x "proc unknown {[info args unknown]} {$x}"rdt 2006.07.13 - With some changes, that is what I did to use the 8.4 unknown. Is there some reason that you did not use the history.tcl present in the distribution or is not present in yours? I made use of it myself.
slebetman: I didn't know how to use it. I thought that history would always take the last executed command which also means the code in tclline itself. Now that I've tried it I see that's not really the case. But I still prefer my implementation since it removes duplicate events (This have been my pet peeve with almost all implementations of history, from tcl to bash to DOSKEY). Besides, an implementation of history is really is almost nothing. It is merely an lappend to a list.
rdt 2006.07.14 - I understand what you are saying, however: history can be used in at least two ways. Suppose that you need to redo a command from much earlier but don't remember the id. You 'history | grep <something_unique>' and discover that it was 987. You can then '!987' and redo it. You do a few commands and then say '!-3' to redo it again. If you don't put duplicates in the list (or keep up with all the id's for a command), then one of these capabilities gets lost. I think what you really want is to keep all the items in the list but be able to display the list in several different ways: a) 'history' for the default full list, b) 'history -20' for the 20 most recent, c) 'history -b' for the list without duplicates, but show the first & last id, and d) 'history <some_re>' to show only those items that match <some_re>.
SRIV I prefer the current optimized history. Its quick and simple and conforms to the 80/20 rule. A grep-able history is nifty, but If I need that, I shouldn't be doing work in a single console anway. I'd switch my devel work to a gui workstation.