+ if {$ch eq "\\"} {
+ if {$used >= [string length $str]} {
+ error "trailing backslash"
+ }
+ append ret [string index $str $used]
+ continue
+ }
+ # here ch == "\""
+ while {1} {
+ if {![regexp -start $used -indices "\[\"\\\\]" $str first]} {
+ error "unmatched double-quote"
+ }
+ set first [lindex $first 0]
+ set ch [string index $str $first]
+ if {$first > $used} {
+ append ret [string range $str $used [expr {$first - 1}]]
+ set used $first
+ }
+ if {$ch eq "\""} break
+ incr used
+ append ret [string index $str $used]
+ incr used
+ }
+ }
+ return [list $used $ret]
+}
+
+proc shellsplit {str} {
+ set l {}
+ while {1} {
+ set str [string trimleft $str]
+ if {$str eq {}} break
+ set dq [shelldequote $str]
+ set n [lindex $dq 0]
+ set word [lindex $dq 1]
+ set str [string range $str $n end]
+ lappend l $word