Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

unset(n) [osx man page]

unset(n)						       Tcl Built-In Commands							  unset(n)

__________________________________________________________________________________________________________________________________________________

NAME
unset - Delete variables SYNOPSIS
unset ?-nocomplain? ?--? ?name name name ...? _________________________________________________________________ DESCRIPTION
This command removes one or more variables. Each name is a variable name, specified in any of the ways acceptable to the set command. If a name refers to an element of an array then that element is removed without affecting the rest of the array. If a name consists of an array name with no parenthesized index, then the entire array is deleted. The unset command returns an empty string as result. If -nocom- plain is specified as the first argument, any possible errors are suppressed. The option may not be abbreviated, in order to disambiguate it from possible variable names. The option -- indicates the end of the options, and should be used if you wish to remove a variable with the same name as any of the options. If an error occurs, any variables after the named one causing the error are not deleted. An error can occur when the named variable does not exist, or the name refers to an array element but the variable is a scalar, or the name refers to a variable in a non-existent namespace. EXAMPLE
Create an array containing a mapping from some numbers to their squares and remove the array elements for non-prime numbers: array set squares { 1 1 6 36 2 4 7 49 3 9 8 64 4 16 9 81 5 25 10 100 } puts "The squares are:" parray squares unset squares(1) squares(4) squares(6) unset squares(8) squares(9) squares(10) puts "The prime squares are:" parray squares SEE ALSO
set(n), trace(n), upvar(n) KEYWORDS
remove, variable Tcl 8.4 unset(n)

Check Out this Related Man Page

set(n)							       Tcl Built-In Commands							    set(n)

__________________________________________________________________________________________________________________________________________________

NAME
set - Read and write variables SYNOPSIS
set varName ?value? _________________________________________________________________ DESCRIPTION
Returns the value of variable varName. If value is specified, then set the value of varName to value, creating a new variable if one doesn't already exist, and return its value. If varName contains an open parenthesis and ends with a close parenthesis, then it refers to an array element: the characters before the first open parenthesis are the name of the array, and the characters between the parentheses are the index within the array. Otherwise varName refers to a scalar variable. Normally, varName is unqualified (does not include the names of any containing namespaces), and the variable of that name in the current namespace is read or written. If varName includes names- pace qualifiers (in the array name if it refers to an array element), the variable in the specified namespace is read or written. If no procedure is active, then varName refers to a namespace variable (global variable if the current namespace is the global namespace). If a procedure is active, then varName refers to a parameter or local variable of the procedure unless the global command was invoked to declare varName to be global, or unless a variable command was invoked to declare varName to be a namespace variable. SEE ALSO
expr(n), proc(n), trace(n), unset(n) KEYWORDS
read, write, variable Tcl set(n)
Man Page

15 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

how to remove first two latter of any string

Hi, I have a variable with contain "fl080114". I want only "080114" into an another variable. input: name="fl080114" output: nm="080114" Please help. Thanks in advance. (2 Replies)
Discussion started by: rinku
2 Replies

2. UNIX for Dummies Questions & Answers

Remove duplicate in array

Hi, I have a list of numbers stored in an array as below. 5 7 10 30 30 40 50 Please advise how could I remove the duplicate value in the array ? Thanks in advance. (5 Replies)
Discussion started by: Rock
5 Replies

3. Shell Programming and Scripting

unix array

Hi , suppose , i have a array variable with size 40 and i have assign a 10 character values. I want to print the array like ,the 10 caharacter value with rest 30 character as blank, if i assigned any blank values also .it will print 40 blank space. Please help me regaring this.It is very... (5 Replies)
Discussion started by: julirani
5 Replies

4. Shell Programming and Scripting

How to unset all variables in shell?

can I use unset to unset all the variables in a shell sciprt? VAR1=1 VAR2=2 VAR3=3 unset whether this unset will afftect any system variables? Thanks, (3 Replies)
Discussion started by: balamv
3 Replies

5. Shell Programming and Scripting

HELP unsetting array element in loop

I have a loop and I need to be able to unset the array element that I am currently accessing in it. I was thinking of making a counter that increments with the loop and doing unset $dirs but if I do that I am not sure if the other members of the array would get shifted down in index (meaning that... (2 Replies)
Discussion started by: msf5042
2 Replies

6. Shell Programming and Scripting

remove an element from array

I need to remove an element from the below array variable TABLENAME. #!/bin/ksh set -A TABLENAME "mirf roxar keke mirs" echo "the array is ${TABLENAME}" If i need to remove say keke and have the final TABLENAME as below, how this could be achieved. Pls throw some light. echo "Modified... (3 Replies)
Discussion started by: michaelrozar17
3 Replies

7. UNIX for Advanced & Expert Users

unset .bashrc

Could someone please tell me how to unset your .bashrc? I have tried all of these. I can't find anything useful from google. unset -f .bashrc unset .bashrc (9 Replies)
Discussion started by: cokedude
9 Replies

8. Shell Programming and Scripting

Processing text variables that have numbers in CShell

Hello, I have a case where I need to process an environment variable text value in CShell to calculate the product of 2 numbers stated in the variable string having the format "<first_number>Letter x<second_number>". Ex: $VAR = "24x20" I need to set $VAR_PRODUCT = "Product of 20 and 24"... (3 Replies)
Discussion started by: mohy
3 Replies

9. Shell Programming and Scripting

[ask] about unset variables

I'm wondering, is the number of variables will affect execution time of my bash script or maybe affect the cpu workload, cpu memory, etc ? If I create so many variables, should I unset each one of that variables after I used them or after I think they are no longer needed? and if my script... (2 Replies)
Discussion started by: 14th
2 Replies

10. Shell Programming and Scripting

Adding an element to a bash array with a variable

Hello, I have a simple task and I am having some trouble with the syntax. I have a variable with an assigned value, CMD_STRING='-L 22 -s 0 -r -O -A i -N 100 -n' I would like to add that variable to an array. As far as I have been able to look up, the syntax should be something like, ... (4 Replies)
Discussion started by: LMHmedchem
4 Replies

11. UNIX for Dummies Questions & Answers

Unset environement variable

Hi, I have the following line in the script unset _SET_ENV_AA unset _SETENV but where I can check the value for this environement variable (2 Replies)
Discussion started by: stew
2 Replies

12. UNIX for Dummies Questions & Answers

Where unset command locates?

Hi, Can someone tell what is the path for "unset", I tried "which" command but getting below error # which unset /usr/bin/which: no unset in (/usr/lib/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin/:/root/bin) (9 Replies)
Discussion started by: stew
9 Replies

13. UNIX for Dummies Questions & Answers

Replace variable string with text

Hi All, Hoping someone can help.... I am trying to work out how I can ammend a log file to remove variable strings in order to remove confidential information which I cant pass on. As an example I have used phone numbers. A large log file contains multiple lines containing something like the... (6 Replies)
Discussion started by: mutley2202
6 Replies

14. Shell Programming and Scripting

Comparing a list of numbers is less than a variable

Hello everyone, I want to compare a list of numbers in the file TEST01 to the variable $Post. Also remove any duplicate numbers. Create an if then statement indicating if the numbers listed in TEST01 is less than the number value of $Post then print an error message. Here is the contents of... (5 Replies)
Discussion started by: seekryts15
5 Replies

15. UNIX for Beginners Questions & Answers

Unset array element and save to file in Bash

#!/bin/bash X=(2H 4S 10D QC JD 9H 8S) How do I unset the 10D from this array and save it to a file? Please use CODE tags as required by forum rules! (5 Replies)
Discussion started by: cogiz
5 Replies