How to get names of variables are available/set in shell scripts

Question

I want all variables names are set in shell script. I have a file which contains key value pairs and I was read content from that file and store/set into variables. I want to do some processes if a variable is available/set otherwise I don't need to do those processes. How to achieve this.

For example I run loop in shell scripts in each iteration it gives one of the variables is set before that command.

If code like this

a=test1
b=test2
c=test3

for i in ???
do
    echo $i
done

then I want output like this

a b c

What command is used o achieve this.

Something like this might help: http://stackoverflow.com/questions/1305237/how-to-list-variables-declared-in-script-in-bash — nitishagar, Dec 29 '15 at 08:31
There is any command for find variable by the suffix of that variable? — Jeeva, Dec 29 '15 at 10:51

score 1 · Answer 1 · answered Dec 29 '15 at 08:33

1

You could use set before and after setting the variables

e.g:

$ set > aux1
$ c=345
$ set > aux2
$ diff aux1 aux2
57c57
< PIPESTATUS=([0]="141" [1]="0")
---
> PIPESTATUS=([0]="0")
112a113
> c=345

answered Dec 29 '15 at 08:33

malarres

2,941
1
21
35

score 0 · Answer 2 · answered Dec 29 '15 at 08:32

0

If you have a pre-defined list of such variables, then you can test it like this:

for i in $(echo "a b c"); do
    echo $i
done

answered Dec 29 '15 at 08:32

Vasily G

859
8
16

I don't know the variable names because it created dynamically from input file. The above code is sample for what result i want. – Jeeva Dec 29 '15 at 10:09

Mirouf · Answer 3 · 2015-12-29T09:21:55.783

If i could help you :

#!/bin/sh

#   Define list of tests
LIST_TESTS=`cat list_test.txt`

for TEST in ${LIST_TESTS}
do
    vartest=`echo ${TEST}`
    if [  "${vartest}" = "" ]
    # No Test
      then
        echo "*** WARNING***  Test not found"   
    else
        echo "${vartest} is available"
    fi
done

#   Second Define list of tests
tabTest=('test1' 'test2' 'test3')

i=0
while  [ "${tabTest[$i]}" != "" ]
do
    echo "${tabTest[$i]} is available"
    i=$(($i+1))
done

How to get names of variables are available/set in shell scripts

3 Answers3