Avoiding Shell Script Brace Expansion

Woodsman · 05-30-2008, 07:40 PM

I'm trying to run a single conky command from within a shell script. The following line works fine when run directly from the command line:

conky -t '${color green}/dev/sdd Temp:${color white} ${hddtemp /dev/sdd}' -x 290 -y 290

Of course, from within a shell script the shell interpreter sees the braces and applies brace expansion. I have tried to enclose the braces with single quotation marks, or preceded by a backslash, but the command always fails.

I would be grateful for some help.

Thanks again.

pixellany · 05-30-2008, 07:51 PM

As far as I know, a bash command follows the same rules in a terminal and in a script. In your example the single quotes should stop the shell from interpreting the contents in either case.

How does the command fail, and how do you know that it involves "brace expansion"?

grizly · 05-30-2008, 07:51 PM

Try different shells..

#!/bin/bash
#!/bin/tsch
#!/bin/csh
#!/bin/ksh

there has to be one that does what you want..

Try using the same shell as your command line, as you say it works that way.

Woodsman · 05-30-2008, 08:36 PM

Oops, I forgot to add that in my script I actually was using a variable for /dev/sdd....

Quote:

In your example the single quotes should stop the shell from interpreting the contents in either case.

Well....crap.

Based upon your statement I tried again.

I finally realized I could use multiple sets of quotation marks.

This finally succeeded:

conky -t '${color green}'$BACKUPDISK' Temp:${color white} ${hddtemp '$BACKUPDISK'}' -x 290 -y 290

Oh well, I hope this helps future readers of this thread!

Thanks for the clue that helped me!

jong357 · 05-31-2008, 09:36 AM

We just had an old sed post revived concerning this very same thing.