bash script not reading alias in bashrc

Question

I have created an alias in the .bashrc file:

alias java='java -Xmx1200m'

This alias works when I run a java command from my shell directly.

However, when the java command is inside a bash script (script.sh), this alias does not get activated. How do I ensure that the aliases in .bashrc file are accepted in a bash script ??

score 7 · Accepted Answer · edited Jul 18 '13 at 14:00

7

Alias are not expanded in non-interactive shells.

The only way to make an alias is to source the target script with the one which contains the alias.

$ source .bashrc
$ . custom_script.sh

edited Jul 18 '13 at 14:00

chepner

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answered Jul 18 '13 at 13:56

epsilon

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only working method for my mac m1 – SKLTFZ Aug 29 '22 at 01:55

score 4 · Answer 2 · answered Jul 18 '13 at 14:03

4

Quoting from the bash manual:

Aliases are not expanded when the shell is not interactive, unless the expand_aliases shell option is set using shopt (see The Shopt Builtin).

Saying the following in your script should make it work:

shopt -s expand_aliases

answered Jul 18 '13 at 14:03

devnull

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Not working in FreeBSD/OSX at least. `expand_aliases` is already on by default. – Ain Tohvri Dec 05 '13 at 12:18
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@AinTohvri You'd need to `source $HOME/.bashrc` in the script. – devnull Dec 05 '13 at 12:24
Yup, after the `shopt -s expand_aliases`, realised that. Working now, thanks! – Ain Tohvri Dec 05 '13 at 14:02

score 1 · Answer 3 · answered Jul 18 '13 at 13:50

1

Aliases are limited to the shell and do not work in executed shell scripts. You are better off creating a variable.

answered Jul 18 '13 at 13:50

jaypal singh

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What about using `export java='java -Xmx1200m'` in `.bashrc`? – fedorqui Jul 18 '13 at 13:53
if the shell script is executed outside of the user login i.e. cron it may not get called - he needs to source .bashrc – V H Jul 18 '13 at 13:55
@fedorqui Right, but that will not be considered using it as an alias. It is setting a global variable. – jaypal singh Jul 18 '13 at 13:58

score 1 · Answer 4 · answered Jul 06 '17 at 23:50

The simplest answer is to do the 2 important things or it wont' work. In your other script, do the following: -i for interactive mode, and shopt part as mentioned below.

#!/bin/bash -i

# Expand aliases defined in the shell ~/.bashrc
shopt -s expand_aliases

After this, your aliases that you have defined in ~/.bashrc they will be available in your shell script (giga.sh or any.sh) and to any function or child shell within such script.

If you don't do that, you'll get an error:

your_cool_alias: command not found

score 0 · Answer 5 · answered Dec 25 '13 at 08:59

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You can run your script under bash bash in interactive mode; add -i to bash command line, like this script. Now you can use your aliases.

#!/bin/bash -i 

alias lsd='ls -al | grep ^d' 

lsd

answered Dec 25 '13 at 08:59

MichaelMoser

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bash script not reading alias in bashrc

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