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Top Forums Shell Programming and Scripting create variable name based on another variable's value Post 302143461 by aigles on Thursday 1st of November 2007 12:27:06 PM
Old 11-01-2007
You can do something like that :
Code:
VAR1=COMPUTER1

flag_name=${VAR1}_FLAG
eval ${flag_name}=N
eval flag_value=\$$flag_name

# With Bash

flag_name=${VAR1}_FLAG
eval ${flag_name}='Y'
flag_value=${!flag_name}

Execution output with trace option:
Code:
+ VAR1=COMPUTER1
+ flag_name=COMPUTER1_FLAG
+ eval COMPUTER1_FLAG=N
++ COMPUTER1_FLAG=N
+ eval 'flag_value=$COMPUTER1_FLAG'
++ flag_value=N
+ flag_name=COMPUTER1_FLAG
+ eval COMPUTER1_FLAG=Y
++ COMPUTER1_FLAG=Y
+ flag_value=Y

Jean-Pierre.

Last edited by aigles; 11-01-2007 at 03:36 PM..
 

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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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