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Top Forums Shell Programming and Scripting bash - Variable made of variable Post 302392825 by jolecanard on Friday 5th of February 2010 03:51:20 PM
Old 02-05-2010
bash - Variable made of variable

Hello,

I am struggling with using variable made using "eval".

Code:
a=4
eval b$a=20

echo $b$a ??? [does not work]

As shown above, I am trying to call back the variable "bX" assuming I do not know the value of "a".

How can I do that?
I tried several combinations but nothing worked.

Thanks
 

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eval(1T)						       Tcl Built-In Commands							  eval(1T)

__________________________________________________________________________________________________________________________________________________

NAME
eval - Evaluate a Tcl script SYNOPSIS
eval arg ?arg ...? _________________________________________________________________ DESCRIPTION
Eval takes one or more arguments, which together comprise a Tcl script containing one or more commands. Eval concatenates all its argu- ments in the same fashion as the concat command, passes the concatenated string to the Tcl interpreter recursively, and returns the result of that evaluation (or any error generated by it). Note that the list command quotes sequences of words in such a way that they are not further expanded by the eval command. EXAMPLE
This procedure acts in a way that is analogous to the lappend command, except it inserts the argument values at the start of the list in the variable: proc lprepend {varName args} { upvar 1 $varName var # Ensure that the variable exists and contains a list lappend var # Now we insert all the arguments in one go set var [eval [list linsert $var 0] $args] } KEYWORDS
concatenate, evaluate, script SEE ALSO
catch(1T), concat(1T), error(1T), list(1T), subst(1T), tclvars(1T) ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +--------------------+-----------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +--------------------+-----------------+ |Availability | SUNWTcl | +--------------------+-----------------+ |Interface Stability | Uncommitted | +--------------------+-----------------+ NOTES
Source for Tcl is available on http://opensolaris.org. Tcl eval(1T)
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