3 # Implementation of the history command.
7 # Copyright (c) 1997 Sun Microsystems, Inc.
9 # See the file "license.terms" for information on usage and redistribution
10 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
13 # The tcl::history array holds the history list and
14 # some additional bookkeeping variables.
16 # nextid the index used for the next history list item.
17 # keep the max size of the history list
18 # oldest the index of the oldest item in the history.
22 if {![info exists history]} {
33 # This is the main history command. See the man page for its interface.
34 # This does argument checking and calls helper procedures in the
38 set len [llength $args]
40 return [tcl::HistInfo]
42 set key [lindex $args 0]
43 set options "add, change, clear, event, info, keep, nextid, or redo"
44 switch -glob -- $key {
48 return -code error "wrong # args: should be \"history add event ?exec?\""
50 if {![string match $key* add]} {
51 return -code error "bad option \"$key\": must be $options"
54 set arg [lindex $args 2]
55 if {! ([string match e* $arg] && [string match $arg* exec])} {
56 return -code error "bad argument \"$arg\": should be \"exec\""
59 return [tcl::HistAdd [lindex $args 1] [lindex $args 2]]
61 ch* { # history change
63 if {($len > 3) || ($len < 2)} {
64 return -code error "wrong # args: should be \"history change newValue ?event?\""
66 if {![string match $key* change]} {
67 return -code error "bad option \"$key\": must be $options"
72 set event [lindex $args 2]
75 return [tcl::HistChange [lindex $args 1] $event]
80 return -code error "wrong # args: should be \"history clear\""
82 if {![string match $key* clear]} {
83 return -code error "bad option \"$key\": must be $options"
85 return [tcl::HistClear]
90 return -code error "wrong # args: should be \"history event ?event?\""
92 if {![string match $key* event]} {
93 return -code error "bad option \"$key\": must be $options"
98 set event [lindex $args 1]
100 return [tcl::HistEvent $event]
105 return -code error "wrong # args: should be \"history info ?count?\""
107 if {![string match $key* info]} {
108 return -code error "bad option \"$key\": must be $options"
110 return [tcl::HistInfo [lindex $args 1]]
115 return -code error "wrong # args: should be \"history keep ?count?\""
118 return [tcl::HistKeep]
120 set limit [lindex $args 1]
121 if {[catch {expr {~$limit}}] || ($limit < 0)} {
122 return -code error "illegal keep count \"$limit\""
124 return [tcl::HistKeep $limit]
127 n* { # history nextid
130 return -code error "wrong # args: should be \"history nextid\""
132 if {![string match $key* nextid]} {
133 return -code error "bad option \"$key\": must be $options"
135 return [expr {$tcl::history(nextid) + 1}]
140 return -code error "wrong # args: should be \"history redo ?event?\""
142 if {![string match $key* redo]} {
143 return -code error "bad option \"$key\": must be $options"
145 return [tcl::HistRedo [lindex $args 1]]
148 return -code error "bad option \"$key\": must be $options"
155 # Add an item to the history, and optionally eval it at the global scope
158 # command the command to add
159 # exec (optional) a substring of "exec" causes the
160 # command to be evaled.
162 # If executing, then the results of the command are returned
165 # Adds to the history list
167 proc tcl::HistAdd {command {exec {}}} {
169 set i [incr history(nextid)]
170 set history($i) $command
171 set j [incr history(oldest)]
172 if {[info exists history($j)]} {unset history($j)}
173 if {[string match e* $exec]} {
174 return [uplevel #0 $command]
182 # Set or query the limit on the length of the history list
185 # limit (optional) the length of the history list
188 # If no limit is specified, the current limit is returned
191 # Updates history(keep) if a limit is specified
193 proc tcl::HistKeep {{limit {}}} {
195 if {[string length $limit] == 0} {
196 return $history(keep)
198 set oldold $history(oldest)
199 set history(oldest) [expr {$history(nextid) - $limit}]
200 for {} {$oldold <= $history(oldest)} {incr oldold} {
201 if {[info exists history($oldold)]} {unset history($oldold)}
203 set history(keep) $limit
209 # Erase the history list
218 # Resets the history array, except for the keep limit
220 proc tcl::HistClear {} {
222 set keep $history(keep)
224 array set history [list \
233 # Return a pretty-printed version of the history list
236 # num (optional) the length of the history list to return
239 # A formatted history list
241 proc tcl::HistInfo {{num {}}} {
244 set num [expr {$history(keep) + 1}]
248 for {set i [expr {$history(nextid) - $num + 1}]} \
249 {$i <= $history(nextid)} {incr i} {
250 if {![info exists history($i)]} {
253 set cmd [string trimright $history($i) \ \n]
254 regsub -all \n $cmd "\n\t" cmd
255 append result $newline[format "%6d %s" $i $cmd]
263 # Fetch the previous or specified event, execute it, and then
264 # replace the current history item with that event.
267 # event (optional) index of history item to redo. Defaults to -1,
268 # which means the previous event.
271 # Those of the command being redone.
274 # Replaces the current history list item with the one being redone.
276 proc tcl::HistRedo {{event -1}} {
278 if {[string length $event] == 0} {
281 set i [HistIndex $event]
282 if {$i == $history(nextid)} {
283 return -code error "cannot redo the current event"
292 # Map from an event specifier to an index in the history list.
295 # event index of history item to redo.
296 # If this is a positive number, it is used directly.
297 # If it is a negative number, then it counts back to a previous
298 # event, where -1 is the most recent event.
299 # A string can be matched, either by being the prefix of
300 # a command or by matching a command with string match.
303 # The index into history, or an error if the index didn't match.
305 proc tcl::HistIndex {event} {
307 if {[catch {expr {~$event}}]} {
308 for {set i [expr {$history(nextid)-1}]} {[info exists history($i)]} \
310 if {[string match $event* $history($i)]} {
313 if {[string match $event $history($i)]} {
317 return -code error "no event matches \"$event\""
318 } elseif {$event <= 0} {
319 set i [expr {$history(nextid) + $event}]
323 if {$i <= $history(oldest)} {
324 return -code error "event \"$event\" is too far in the past"
326 if {$i > $history(nextid)} {
327 return -code error "event \"$event\" hasn't occured yet"
334 # Map from an event specifier to the value in the history list.
337 # event index of history item to redo. See index for a
338 # description of possible event patterns.
341 # The value from the history list.
343 proc tcl::HistEvent {event} {
345 set i [HistIndex $event]
346 if {[info exists history($i)]} {
347 return [string trimright $history($i) \ \n]
355 # Replace a value in the history list.
358 # cmd The new value to put into the history list.
359 # event (optional) index of history item to redo. See index for a
360 # description of possible event patterns. This defaults
361 # to 0, which specifies the current event.
364 # Changes the history list.
366 proc tcl::HistChange {cmd {event 0}} {
368 set i [HistIndex $event]