TCL script: variable as argument of a function

Question

I am trying some simple scripting with Amira, which uses TCL but I cannot assure that it's the standard version. I want to read a property from an object and assign it to another object.

In the command window the procedure would be the following:

Image1 getTransform

0.1 0.2 0.3 0 0 0 0 0 0 1

Image2 setTransform 0.1 0.2 0.3 0 0 0 0 0 0 1

I want to do the same without manually copy pasting the result of getTransform

The following do not work (taht is to say setTransform is executed without arguments)

Image2 setTransform [Image1 getTransform]

or

set myT=Image1 getTransform
Image2 setTransform $myT

I am sure I just need to appropriately use $ [ { , but what I've tried so far has not given any result

The command to determine the Tcl version is `info patchlevel` — glenn jackman, Feb 01 '13 at 20:42

score 5 · Accepted Answer · answered Jan 30 '13 at 12:04

5

If you are using Tcl 8.5 or newer, then use the {*} argument expansion:

Image2 setTransform {*}[Image1 getTransform]

which is exactly what you want.

If you are using an older version of Tcl, then you have to use eval, a very useful command, where many things can go wrong if not used correctly:

eval [linsert [Image1 getTransform] 0 Image2 setTransform]

The linsert is used here to build up a propper list to avoid double substitution (which is almost always bad).

answered Jan 30 '13 at 12:04

Johannes Kuhn

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Thank you, both instructions work! - but I prefer the first one :) – lib Jan 30 '13 at 15:32
Right, the first one is the better one. But it only works with Tcl 8.5 or newer. – Johannes Kuhn Jan 30 '13 at 21:30

TCL script: variable as argument of a function

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