Using the exec command 
Author Message
 Using the exec command

I have been having a rough time getting the tcl parser to take a pipe in the
exec command such as this one below:

set temp [exec du -sk /.cache/swap | nawk '{print $1}']

It often complains about the $1 not being a recognized variable so I can put
a "\" delimiter in front of it but then it prints out the result of the du
command followed by |0nawk0'{print0$1}'

Any idea the best way to exec sub-processes and pipe commands together and
set a variable to the result?

Please email me direct.



Mon, 12 Jan 1998 03:00:00 GMT  
 Using the exec command


Yeah I am a newbie to tcl/tk and to this newsgroup also. I think tcl/tk is very
cool but unfortunatly I have had zero luck getting the hang of it! I have programmed
maily in korn shell in the past but have done Bourne, Csh, C, C++ I am trying to learn
Tcl/Tk from John K. Ousterhout's book. I am used to using all of the Unix Util's such
as nawk, sed, grep, sort. I often pipe a lot of these together and set a variable to
the result. This is a snap in Korn Shell but I can't do it in tcl yet I am really
stumped trying to get exec to do anything other than one simple command at a time.

Can someone suggest a good way for me to do those kinds of things with pipes? Is
exec the wrong command? When do I use eval? Also I am a bit confused what are the
differences in binding a command to a widget or using -command option on the widget?

Last but not least is there a way to display a scale that changes with a variables
state but does not give the using a slider button, or at least disables the slider?

Thanks alot, and I'll keep reading the book.


Mon, 12 Jan 1998 03:00:00 GMT  
 [ 3 post ] 

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