archie/tcl7.3/library/init.tcl

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2024-05-27 16:13:40 +02:00
# init.tcl --
#
# Default system startup file for Tcl-based applications. Defines
# "unknown" procedure and auto-load facilities.
#
# $Header: /user6/ouster/tcl/library/RCS/init.tcl,v 1.28 93/10/08 09:11:21 ouster Exp $ SPRITE (Berkeley)
#
# Copyright (c) 1991-1993 The Regents of the University of California.
# All rights reserved.
#
# Permission is hereby granted, without written agreement and without
# license or royalty fees, to use, copy, modify, and distribute this
# software and its documentation for any purpose, provided that the
# above copyright notice and the following two paragraphs appear in
# all copies of this software.
#
# IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
# DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
# OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
# CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
# ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
# PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
#
set auto_path [info library]
# unknown:
# Invoked when a Tcl command is invoked that doesn't exist in the
# interpreter:
#
# 1. See if the autoload facility can locate the command in a
# Tcl script file. If so, load it and execute it.
# 2. See if the command exists as an executable UNIX program.
# If so, "exec" the command.
# 3. If the command was invoked at top-level:
# (a) see if the command requests csh-like history substitution
# in one of the common forms !!, !<number>, or ^old^new. If
# so, emulate csh's history substitution.
# (b) see if the command is a unique abbreviation for another
# command. If so, invoke the command.
proc unknown args {
global auto_noexec auto_noload env unknown_pending tcl_interactive;
set name [lindex $args 0]
if ![info exists auto_noload] {
#
# Make sure we're not trying to load the same proc twice.
#
if [info exists unknown_pending($name)] {
unset unknown_pending($name)
if {[array size unknown_pending] == 0} {
unset unknown_pending
}
return -code error "self-referential recursion in \"unknown\" for command \"$name\"";
}
set unknown_pending($name) pending;
set ret [catch {auto_load $name} msg]
unset unknown_pending($name);
if {$ret != 0} {
return -code $ret "error while autoloading \"$name\": $msg"
}
if ![array size unknown_pending] {
unset unknown_pending
}
if $msg {
return [uplevel $args]
}
}
if {([info level] == 1) && ([info script] == "") && $tcl_interactive} {
if ![info exists auto_noexec] {
if [auto_execok $name] {
return [uplevel exec >&@stdout <@stdin $args]
}
}
if {$name == "!!"} {
return [uplevel {history redo}]
}
if [regexp {^!(.+)$} $name dummy event] {
return [uplevel [list history redo $event]]
}
if [regexp {^\^([^^]*)\^([^^]*)\^?$} $name dummy old new] {
return [uplevel [list history substitute $old $new]]
}
set cmds [info commands $name*]
if {[llength $cmds] == 1} {
return [uplevel [lreplace $args 0 0 $cmds]]
}
if {[llength $cmds] != 0} {
if {$name == ""} {
return -code error "empty command name \"\""
} else {
return -code error \
"ambiguous command name \"$name\": [lsort $cmds]"
}
}
}
return -code error "invalid command name \"$name\""
}
# auto_load:
# Checks a collection of library directories to see if a procedure
# is defined in one of them. If so, it sources the appropriate
# library file to create the procedure. Returns 1 if it successfully
# loaded the procedure, 0 otherwise.
proc auto_load cmd {
global auto_index auto_oldpath auto_path env errorInfo errorCode
if [info exists auto_index($cmd)] {
uplevel #0 $auto_index($cmd)
return 1
}
if [catch {set path $auto_path}] {
if [catch {set path $env(TCLLIBPATH)}] {
if [catch {set path [info library]}] {
return 0
}
}
}
if [info exists auto_oldpath] {
if {$auto_oldpath == $path} {
return 0
}
}
set auto_oldpath $path
catch {unset auto_index}
for {set i [expr [llength $path] - 1]} {$i >= 0} {incr i -1} {
set dir [lindex $path $i]
set f ""
if [catch {set f [open $dir/tclIndex]}] {
continue
}
set error [catch {
set id [gets $f]
if {$id == "# Tcl autoload index file, version 2.0"} {
eval [read $f]
} elseif {$id == "# Tcl autoload index file: each line identifies a Tcl"} {
while {[gets $f line] >= 0} {
if {([string index $line 0] == "#")
|| ([llength $line] != 2)} {
continue
}
set name [lindex $line 0]
set auto_index($name) "source $dir/[lindex $line 1]"
}
} else {
error "$dir/tclIndex isn't a proper Tcl index file"
}
} msg]
if {$f != ""} {
close $f
}
if $error {
error $msg $errorInfo $errorCode
}
}
if [info exists auto_index($cmd)] {
uplevel #0 $auto_index($cmd)
if {[info commands $cmd] != ""} {
return 1
}
}
return 0
}
# auto_execok:
# Returns 1 if there's an executable in the current path for the
# given name, 0 otherwise. Builds an associative array auto_execs
# that caches information about previous checks, for speed.
proc auto_execok name {
global auto_execs env
if [info exists auto_execs($name)] {
return $auto_execs($name)
}
set auto_execs($name) 0
if {[string first / $name] >= 0} {
if {[file executable $name] && ![file isdirectory $name]} {
set auto_execs($name) 1
}
return $auto_execs($name)
}
foreach dir [split $env(PATH) :] {
if {[file executable $dir/$name] && ![file isdirectory $dir/$name]} {
set auto_execs($name) 1
return 1
}
}
return 0
}
# auto_reset:
# Destroy all cached information for auto-loading and auto-execution,
# so that the information gets recomputed the next time it's needed.
# Also delete any procedures that are listed in the auto-load index
# except those related to auto-loading.
proc auto_reset {} {
global auto_execs auto_index auto_oldpath
foreach p [info procs] {
if {[info exists auto_index($p)] && ($p != "unknown")
&& ![string match auto_* $p]} {
rename $p {}
}
}
catch {unset auto_execs}
catch {unset auto_index}
catch {unset auto_oldpath}
}
# auto_mkindex:
# Regenerate a tclIndex file from Tcl source files. Takes as argument
# the name of the directory in which the tclIndex file is to be placed,
# floowed by any number of glob patterns to use in that directory to
# locate all of the relevant files.
proc auto_mkindex {dir args} {
global errorCode errorInfo
set oldDir [pwd]
cd $dir
set dir [pwd]
append index "# Tcl autoload index file, version 2.0\n"
append index "# This file is generated by the \"auto_mkindex\" command\n"
append index "# and sourced to set up indexing information for one or\n"
append index "# more commands. Typically each line is a command that\n"
append index "# sets an element in the auto_index array, where the\n"
append index "# element name is the name of a command and the value is\n"
append index "# a script that loads the command.\n\n"
foreach file [eval glob $args] {
set f ""
set error [catch {
set f [open $file]
while {[gets $f line] >= 0} {
if [regexp {^proc[ ]+([^ ]*)} $line match procName] {
append index "set [list auto_index($procName)]"
append index " \"source \$dir/$file\"\n"
}
}
close $f
} msg]
if $error {
set code $errorCode
set info $errorInfo
catch {close $f}
cd $oldDir
error $msg $info $code
}
}
set f [open tclIndex w]
puts $f $index nonewline
close $f
cd $oldDir
}