Since Tcl 8.5 (Dec 2007) interps have timed resource limits available for them. bch$ tclsh8.5 % interp limit {} time -seconds [expr {[clock seconds] + 15}]

Since Tcl 8.5 (Dec 2007) interps have timed resource limits available for them. bch$ tclsh8.5 % interp limit {} time -seconds [expr {[clock seconds] + 15}] % while 1 {set a 9} ;# 15s elapse, then... time limit exceeded bch$ edit: Add release date for Tcl 8.5