# expanding alias from a variable
**URL:** https://community.unix.com/t/expanding-alias-from-a-variable/250267
**Category:** Shell Programming and Scripting
**Created:** [September 29, 2009, 9:40am UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267 "2009-09-29T09:40:50Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@locutus01](https://community.unix.com/u/locutus01)
#### Post date: [September 29, 2009, 9:40am UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/1 "2009-09-29T09:40:50Z")
Hi !
I am making my first steps to make a script. Therefore i try to make a scp command more easier. Given is the following alias:
14='admin@x-abcd-def.xyz
Now i want to let the script read three var's from the console to use them in the script and then build the scp string.
```nohighlight
echo "Servernumber:";
read srv="";
echo "remotefile incl. abs. path";
read remotefile="";
echo "localfile incl. abs.path"
read localfile
scp admin@$srv:$remotefile $localfile
```
Doing it this way $srv is not expanded to the value of the alias. expand\_alias is set to on in the bash. So where is my mistake?
---
### Author:  [@dr.house](https://community.unix.com/u/dr.house)
#### Post date: [September 29, 2009, 10:19am UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/2 "2009-09-29T10:19:50Z")
```nohighlight
#! /bin/bash
echo -n "Server no.: " ; read server
echo -n "Remote file: " ; read remote
echo -n "Local file: " ; read local
echo "SCP:> $server $remote $local"
exit 0
```
```nohighlight
[house@leonov] sh test.bash
Server no.: 12
Remote file: this
Local file: that
SCP:> 12 this that
```
---
### Author:  [@peterro](https://community.unix.com/u/peterro)
#### Post date: [September 29, 2009, 10:24am UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/3 "2009-09-29T10:24:38Z")
Your code isn't consistent even with similar lines. Remove the semi-colons from the end of the lines. Your 'read' lines aren't the same throughout the script either:
```nohighlight
#!/bin/sh
echo "Servernumber:"
read srv
echo "remotefile incl. abs. path"
read remotefile
echo "localfile incl. abs.path"
read localfile
scp admin@$srv:$remotefile $localfile
```
A good method for testing techniques/syntax is to pull just the technique out into a simple 2-3 line script to validate that the code works and then put it into your script.
Something like:
```nohighlight
read something
echo $something
```
or
```nohighlight
srv=box
remotefile=/file
localfile=/another/file
scp admin@$srv:$remotefile $localfile
```
---
### Author:  [@locutus01](https://community.unix.com/u/locutus01)
#### Post date: [September 29, 2009, 5:54pm UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/4 "2009-09-29T17:54:41Z")
> [@dr.house](#):
>
> ```plaintext
> #! /bin/bash
>
> echo -n "Server no.: " ; read server
> echo -n "Remote file: " ; read remote
> echo -n "Local file: " ; read local
>
> echo "SCP:> $server $remote $local"
>
> exit 0
>
> ```
>
> ```plaintext
> [house@leonov] sh test.bash
> Server no.: 12
> Remote file: this
> Local file: that
> SCP:> 12 this that
>
> ```
Ok, but this does not expand the alias for the servername.
---
### Author:  [@peterro](https://community.unix.com/u/peterro)
#### Post date: [September 29, 2009, 6:31pm UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/5 "2009-09-29T18:31:08Z")
Where do the aliases get defined?
---
### Author:  [@locutus01](https://community.unix.com/u/locutus01)
#### Post date: [September 29, 2009, 6:56pm UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/6 "2009-09-29T18:56:05Z")
> [@peterro](#):
>
> Where do the aliases get defined?
~/.bashrc
Works on the console.
---
### Author:  [@peterro](https://community.unix.com/u/peterro)
#### Post date: [September 29, 2009, 7:38pm UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/7 "2009-09-29T19:38:42Z")
That wouldn't be part of your script environment though. Are you using these aliases for something else or mainly this? You could source your .bashrc or keep the definitions in a separate file and source that whenever you have a script that needs to access the definitions.
---
### Author:  [@dr.house](https://community.unix.com/u/dr.house)
#### Post date: [September 30, 2009, 2:36am UTC](https://community.unix.com/t/expanding-alias-from-a-variable/250267/8 "2009-09-30T02:36:05Z")
> [@peterro](#):
>
> You could source your .bashrc or keep the definitions in a separate file and source that whenever you have a script that needs to access the definitions.
Even though this could work ([reference](http://linux.derkeiler.com/Mailing-Lists/Debian/2008-01/msg02570.html)), I'd rather try to keep things separate (- a basic setup I'm using for larger projects: script.main for the main part, script.code for functions and script.data for variables).
--
Further details: [ABS on Aliases](http://tldp.org/LDP/abs/html/aliases.html)