Sponsored Content
Full Discussion: shell variables advanced
Top Forums Shell Programming and Scripting shell variables advanced Post 302338701 by wakatana on Tuesday 28th of July 2009 04:42:52 PM
Old 07-28-2009
shell variables advanced

Hi all, i have more questions but its all about variables so lets begin

1st, is possible to list all variables ?
Command env display only shell variables, but what if i declared another variable? Command set display more variables but not defined by me.

2nd, what difference is between set and env ?

3rd, lets say i declared variable which contains whitespaces, or i have variable which contains whitespaces for example IFS. When i type echo $IFS i see nothing, so i dont know if is declared or if contain white spaces.
Is possible to write white spaces in C format (\n \r \t ...) ?

4th what is difference between sourcing and exporting variable ?




PS: i saw declaration of IFS in set command (IFS=$' \t\n')
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Using shell variables In awk

Oh its not my day for syntax... cat gzipsize.txt | awk '{print "echo",$1,$2} > master.txt I have read a lot about the awk -v but haven't been able to get it to work. I have a variable in my script and I'm looking just to push it into the awk after the $2 (or anywhere would do)!!! Every... (11 Replies)
Discussion started by: nortypig
11 Replies

2. Shell Programming and Scripting

variables in shell

hi, i'm new in shell scripting and i'm working on bash on solaris 5.9 after try many stuff with unexpected results, i wonder: it is not posible in bash, to use a variable that was created inside a loop, out of it? i mean, for instance: cat mytext | \ while read text do viko=$text... (2 Replies)
Discussion started by: viko
2 Replies

3. Post Here to Contact Site Administrators and Moderators

Where can I download the VTC - Unix Shell Scripting Advanced complete video

Where can I download the VTC - Unix Shell Scripting Advanced complete video. I don't know in which thread I should post this question.Plz help me out, or just tell me the link in the reply to this post. Thanks in advance. (0 Replies)
Discussion started by: villain41
0 Replies

4. Shell Programming and Scripting

$0 shell variables

Would appreciate if someone can explain the ${0##*/} line. What does it do? I am aware that $0 is the script name, $# is number of arguments passed in, $* is all the arguments. With the curly brackets {} added in, what's the eventual effect? Does ${0##*/} actually equals $0$#$*? (something like... (3 Replies)
Discussion started by: new2ss
3 Replies

5. Shell Programming and Scripting

Advanced error handling in shell scripts

Hi all I've got a question regarding error handling in shell scripts. My background is mainly object oriented programming languages, but for a year or so I've been doing more and more (bash) shell scripting (which I quite enjoy by the way). To handle errors in my scripts I... (3 Replies)
Discussion started by: script_man
3 Replies

6. Shell Programming and Scripting

Shell advanced syntax?

I am not an expert of shell scripting, but I can do some simple things. Now, I read a script written by others and I need some help from the experts of this forum. Please help me to understand what is going on in this cycle: if ; then ] && \ export... (25 Replies)
Discussion started by: alt
25 Replies

7. Homework & Coursework Questions

Trouble with Advanced Shell Programming

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted! 1. The problem statement, all variables and given/known data: I am working on a hands on project. We are creating a script for a corporate phone list. The project I am... (2 Replies)
Discussion started by: SarahBelle7858
2 Replies

8. Shell Programming and Scripting

awk - take variables out to shell

Hi, How could we take the value of awk variables out to shell? I know the following methods 1. awk '{print $1}' < file | read a echo $a 2. a=`awk '{print $1}' < file` echo $a Please let me know if there are any other methods. Also, how do we take more than 1 variable value... (4 Replies)
Discussion started by: Thumban
4 Replies

9. UNIX for Dummies Questions & Answers

How to write Config shell script to pass variables in master shell script?

Dear Unix gurus, We have a config shell script file which has 30 variables which needs to be passed to master unix shell script that invokes oracle database sessions. So those 30 variables need to go through the database sessions (They are inputs) via a shell script. one of the variable name... (1 Reply)
Discussion started by: dba1981
1 Replies

10. Shell Programming and Scripting

How to write config shell script to pass variables in master shell script?

Dear Unix gurus, We have a config shell script file which has 30 variables which needs to be passed to master unix shell script that invokes oracle database sessions. So those 30 variables need to go through the database sessions (They are inputs) via a shell script. one of the variable name... (1 Reply)
Discussion started by: dba1981
1 Replies
variable(n)						       Tcl Built-In Commands						       variable(n)

__________________________________________________________________________________________________________________________________________________

NAME
variable - create and initialize a namespace variable SYNOPSIS
variable ?name value...? name ?value? _________________________________________________________________ DESCRIPTION
This command is normally used within a namespace eval command to create one or more variables within a namespace. Each variable name is initialized with value. The value for the last variable is optional. If a variable name does not exist, it is created. In this case, if value is specified, it is assigned to the newly created variable. If no value is specified, the new variable is left undefined. If the variable already exists, it is set to value if value is specified or left unchanged if no value is given. Normally, name is unqualified (does not include the names of any containing namespaces), and the variable is created in the current namespace. If name includes any namespace qualifiers, the variable is created in the specified names- pace. If the variable is not defined, it will be visible to the namespace which command, but not to the info exists command. If the variable command is executed inside a Tcl procedure, it creates local variables linked to the corresponding namespace variables (and therefore these variables are listed by info locals.) In this way the variable command resembles the global command, although the global command only links to variables in the global namespace. If any values are given, they are used to modify the values of the associated namespace variables. If a namespace variable does not exist, it is created and optionally initialized. A name argument cannot reference an element within an array. Instead, name should reference the entire array, and the initialization value should be left off. After the variable has been declared, elements within the array can be set using ordinary set or array commands. SEE ALSO
global(n), namespace(n), upvar(n) KEYWORDS
global, namespace, procedure, variable Tcl 8.0 variable(n)
All times are GMT -4. The time now is 09:03 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy