Tcl Script: Invalid command name return when executing proc body -

in tcl script, want catch return of tcl proc in order execute finalization actions. example code follows:

proc x10 { } { return [expr $a * 10] } proc procf {} {     set 13     catch {[info body x10]} __result     return $__result } procf 

the previous code gives me error: invalid command name " return [expr $a * 10] "

although replacing info body x10 return [expr $a * 10] works expected. thought both of them exchangeable , should give same output. so, why first gives error , difference between both of them ?

your code failing because getting body of x10 , treating command name. tcl doesn't split things automatically — have ask — , critical language safety factor. you'd have this:

proc procf {} {     set 13     catch {eval [info body x10]} __result     return __result } 

or (because first argument catch script):

proc procf {} {     set 13     catch [info body x10] __result     return __result } 

but i'd inclined in case (as presented exactly, , trying interpret you've said) do:

proc procf {} {     set 13     catch {x10 $a} __result     return __result } 

note if did this:

proc procf {} {     set 13     catch {info body x10} __result     return __result } 

then result definition of x10 without being evaluated.