Indirect variables in Bash

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Passing awk variables to bash variables

Trying to do so echo "111:222:333" |awk -F: '{system("export TESTO=" $2)}'But it doesn't work

2. Shell Programming and Scripting

BASH arrays and variables of variables in C++

Sometimes it is handy to protect long scripts in C++. The following syntax works fine for simple commands: #define SHELLSCRIPT1 "\ #/bin/bash \n\ echo \"hello\" \n\ " int main () { cout <<system(SHELLSCRIPT1); return 0; } Unfortunately for there are problems for: 1d arrays:...

3. Shell Programming and Scripting

Indirect Referral Script

I have a file with two columns of numbers (member IDs): 1 1 2 1 3 1 4 2 5 4 6 1 7 5 8 3 9 2 Think of column 1 as the referee and column 2 as the referrer. Is there a good way to backtrack who referred who? I would like an output, for this example here to be: 1 1 2 1 3 1 4 2 1

4. Shell Programming and Scripting

Does SH support indirect expansion like BASH?

Hello, is there a kind soul who can answer me, does the SH support double substitution known as indirect expansion similar to BASH? The syntax for bash is ${!var}. For instance in bash I can write something like this: VAR="value" REF_VAR="VAR" echo ${!REF_VAR} and get the "value"...

5. Shell Programming and Scripting

Indirect variable assignment

Hi I have variable A_B=alpha also var1="A" var2="B" I want to retrieve the value alpha using var1 and var2 , somthing like echo ${${var1}_${var2}} that works. Obviously this is receiving syntax error

6. Linux

How to get an Indirect Variable Value..?

Hi, I've got a small problem. If varible A stores "B" and Variable B stores C, How to get the value of variable B by using only Variable A..? I tried the following but didnt work pease help.. $ var1=vikram $ echo $var1 vikram $ vikram=sampath $ echo $vikram sampath $ echo...

7. Shell Programming and Scripting

Bash variables

Ummm can anybody help me with this one? Its prob quite simple. I bascially have a file name say J1x2x3x7.dat Im using the file name as a variable in a bash script. Want I want to do is extract most of the file name and make it a new variable expect with say one of the number now a...

8. Shell Programming and Scripting

Length of an indirect variable

The construct ${#parameter} returns the number of characters in the parameter and ${!parameter} specifies an indirect variable. My question is: How do I combine these two. What I want is ${#!parameter} but this gives an error. Of course I can use: dummy=${!parameter} ${#dummy} but that's a...

9. UNIX for Advanced & Expert Users

Compound indirect variable references

Using bash, I'm trying to read a .properties file (name=value pairs), assigning an indirect variable reference for each line in the file. The trick is that a property's value string may contain the name of a property that occurred earlier in the file, and I want the name of the 1st property to...

LEARN ABOUT FREEBSD

atf-sh

ATF-SH(1)						    BSD General Commands Manual 						 ATF-SH(1)

NAME

     atf-sh [-s shell] -- interpreter for shell-based test programs

SYNOPSIS

     atf-sh script

DESCRIPTION

     atf-sh is an interpreter that runs the test program given in script after loading the atf-sh(3) library.

     atf-sh is not a real interpreter though: it is just a wrapper around the system-wide shell defined by ATF_SHELL.  atf-sh executes the inter-
     preter, loads the atf-sh(3) library and then runs the script.  You must consider atf-sh to be a POSIX shell by default and thus should not
     use any non-standard extensions.

     The following options are available:

     -s shell	  Specifies the shell to use instead of the value provided by ATF_SHELL.

ENVIRONMENT

     ATF_LIBEXECDIR    Overrides the builtin directory where atf-sh is located.  Should not be overridden other than for testing purposes.
     ATF_PKGDATADIR    Overrides the builtin directory where libatf-sh.subr is located.  Should not be overridden other than for testing purposes.
     ATF_SHELL	       Path to the system shell to be used in the generated scripts.  Scripts must not rely on this variable being set to select a
		       specific interpreter.

EXAMPLES

     Scripts using atf-sh(3) should start with:

	   #! /usr/bin/env atf-sh

     Alternatively, if you want to explicitly choose a shell interpreter, you cannot rely on env(1) to find atf-sh.  Instead, you have to hardcode
     the path to atf-sh in the script and then use the -s option afterwards as a single parameter:

	   #! /path/to/bin/atf-sh -s/bin/bash

ENVIRONMENT

     ATF_SHELL	  Path to the system shell to be used in the generated scripts.

SEE ALSO

     atf-sh(3)

BSD
								September 27, 2014							       BSD

Shell Programming and Scripting