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Top Forums UNIX for Advanced & Expert Users Expanding Variables in User Input Post 90110 by nobody4 on Friday 18th of November 2005 09:45:40 AM
Old 11-18-2005
We do need to see your code, but I'll take a guess anyway.
It seems likely that you need something like "eval" to evaluate the assignment.

variable=preset_value
read line
[user input is <newvar=$variable>]
eval "$line"
echo $newvar
preset_value
 

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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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