using exec

[sl1200mk2]

hi there
does someone can explain me how to deal with the exec command.

i'm running mac osx version of tcl.
i'm using tcl as a gui for a program who runs with no-gui, so i need to launch the program when i launch the tcl script.

the name of the no-gui program is pd.
when i use
exec /usr/bin/pd

pd launch but the tcl gui is no more executed.
should i link another script to my tcl one to launch pd?
i've tried with bgexec, but i should miss something because it results the same behaviour

thank you for any helps
nicolas

 

[sl1200mk2]

sorry for the noise

if i put
exec /usr/bin/pd &

the gui appears.....

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