Sponsored Content
Top Forums Shell Programming and Scripting How to evaluate a variable name on LHS of expression? Post 302886800 by RudiC on Monday 3rd of February 2014 05:13:11 PM
Old 02-03-2014
You can't do that. You'll have to
- read $parm < someredirection
- assign to an associative array X[$parm]=...
- eval $parm=... (which brings with it all sorts of escaping needs etc.)
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

how to get variable to re-evaluate itself?

Probably a simple one. Basically I am retrieving a number from a file - setting a variable against it and then incrementing this by 1 and using this as an entry number in a log file for messages. I need the variable to re-evalute itself each time I call it so I get the latest number in the file -... (1 Reply)
Discussion started by: frustrated1
1 Replies

2. Shell Programming and Scripting

Evaluate the value of a variable?

I have variables: FOO="Text" BAR="FOO" I'd like to be able to evaluate the variable named as the value of $BAR. echo $FOO Text echo $BAR FOO This is what I'd like to do: echo ${$BAR} (this won't work) Text (3 Replies)
Discussion started by: Ilja
3 Replies

3. Shell Programming and Scripting

Evaluate string containing shell variable names

Hello, I have this: #!/usr/bin/ksh V1=ABC str="hello 123;${V1}" eval "echo $str" i get hello 123 /script.sh ABC not found However eval works if $str variable doesn't contain a semicolumn (eg if str="hello 123~${v1}" running the eval statement above would produce (2 Replies)
Discussion started by: endorphin
2 Replies

4. Shell Programming and Scripting

Variable expression and while

hi, i'm reading a file "LISTE_FILE" like : # $LOGCOM * 5 $PRCCOM * 10 and i want to use the file with "while" and having the fields splitted into new variables for treatment : while read LINE do # Ignorer les commentaires un # en premiere position if then... (3 Replies)
Discussion started by: Nicol
3 Replies

5. Shell Programming and Scripting

How to evaluate the value of a variable ?

How to evaluate the value of a variable ? For example: a=var $a=value !!!error happens!!! I want to evaluate var=value, how to realize it? Thanks! ---------- Post updated at 03:37 AM ---------- Previous update was at 02:22 AM ---------- I am using linux bash. a=var $a=value... (4 Replies)
Discussion started by: 915086731
4 Replies

6. Shell Programming and Scripting

Using a variable as a for loop expression

I'm writing a script to merge the xkcd webcomic tiles for comic 1110. So far, I have written about 100 lines, and instead of doing each quadrant of the image separately, I've decided to use functions to do this, repeating for every quadrant and using variables for each quadrant to make the function... (9 Replies)
Discussion started by: jbondhus
9 Replies

7. Shell Programming and Scripting

Trying to execute a expression in a variable

Hi i tried to execute a below script but it is giving execution error rec=ABC,1234,55.00 Colno=2 coldel=, fd='"'$coldel'"' fprint="'"'{print$'$colno'}'"'" colsyn=`echo "echo "$rec "| awk -F"$fd $fprint` echo column syntax is $colsyn colrec=`colsyn` echo column is $colrec (5 Replies)
Discussion started by: ragu.selvaraj
5 Replies

8. Shell Programming and Scripting

Evaluate Variable At Runtime

Hi, I am trying to set a variable that has time the format desired. And my intention is to echo variable (instead of actual date command) everytime I like to echo date. Please take a look at below code. $NOW='' echo $NOW After 5 minutes $echo $NOW Issue here is , I am not... (2 Replies)
Discussion started by: vinay4889
2 Replies

9. Shell Programming and Scripting

Evaluate Expression within awk

I want to create a conditional expression string and pass in an awk script. My script is as below... comm="\$3 == "hello"" awk -F "^T" -v command="${comm}" ' { if ( command ) { print "hye" } }' testBut the statement "if ( command )" always evaluates to true which is not... (5 Replies)
Discussion started by: Saikat123
5 Replies

10. UNIX for Advanced & Expert Users

How to evaluate expression under awk?

I have to display only those subscribers which are in "unconnected state" and the date is 90 days older than today's date. Below command is used for this purpose: cat vfsubscriber_20170817.csv | sed -e 's/^"//' -e '1d' | \ nawk -F '",' '{if ( (substr($11,2,4) == 2017) && ( substr($11,2,8)... (1 Reply)
Discussion started by: dia
1 Replies
lassign(3tcl)						       Tcl Built-In Commands						     lassign(3tcl)

__________________________________________________________________________________________________________________________________________________

NAME
lassign - Assign list elements to variables SYNOPSIS
lassign list varName ?varName ...? _________________________________________________________________ DESCRIPTION
This command treats the value list as a list and assigns successive elements from that list to the variables given by the varName arguments in order. If there are more variable names than list elements, the remaining variables are set to the empty string. If there are more list elements than variables, a list of unassigned elements is returned. EXAMPLES
An illustration of how multiple assignment works, and what happens when there are either too few or too many elements. lassign {a b c} x y z ;# Empty return puts $x ;# Prints "a" puts $y ;# Prints "b" puts $z ;# Prints "c" lassign {d e} x y z ;# Empty return puts $x ;# Prints "d" puts $y ;# Prints "e" puts $z ;# Prints "" lassign {f g h i} x y ;# Returns "h i" puts $x ;# Prints "f" puts $y ;# Prints "g" The lassign command has other uses. It can be used to create the analogue of the "shift" command in many shell languages like this: set ::argv [lassign $::argv argumentToReadOff] SEE ALSO
lindex(3tcl), list(3tcl), lset(3tcl), set(3tcl) KEYWORDS
assign, element, list, multiple, set, variable Tcl 8.5 lassign(3tcl)
All times are GMT -4. The time now is 12:53 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy