Question

28

Multi line alias in bash

rated 0 times [ 28] [ 0] / answers: 1 / hits: 30462 / 3 Years ago, thu, november 4, 2021, 6:01:07

I have the following script. It's a simple test case where a is any string value and b is supposed to be a path.

#!/bin/bash



alias jo "

echo "please enter values "

read a 

read -e b 

echo "My values are $a and $b""

However whenever I try to execute ./sample.sh I get the following errors:

./sample.sh: line 3: alias: jo: not found

./sample.sh: line 3: alias: echo please: not found

./sample.sh: line 3: alias: enter: not found

./sample.sh: line 3: alias: values: not found

./sample.sh: line 3: alias: read a read -e b echo My: not found

./sample.sh: line 3: alias: values: not found

./sample.sh: line 3: alias: are: not found

./sample.sh: line 3: alias: and: not found

./sample.sh: line 3: alias: : not found

and when I try source sample.sh I get the following:

a: Undefined variable.

My aim was to make this an alias so that I can source this script and just run the alias to execute the line of commands. Can someone look at this and let me know what the error is?

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dileble

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2 Years ago

answered 3 Years ago pheter · Accepted Answer

You have a couple of issues here

unlike in csh, in bash (and other Bourne-like shells), aliases are assigned with an = sign e.g. alias foo=bar

quotes can't be nested like that; in this case, you can use single quotes around the alias and double quotes inside

the backslash is a line continuation character: syntactically, it makes your command into a single line (the opposite of what you want)

So

#!/bin/bash



alias jo='

echo "please enter values "

read a 

read -e b 

echo "My values are $a and $b"'

Testing: first we source the file:

$ . ./myscript.sh

then

$ jo

please enter values 

foo bar

baz

My values are foo bar and baz

If you want to use the alias within a script, then remember that aliases are only enabled by default in interactive shells: to enable them inside a script you will need to add

shopt -s expand_aliases

Regardless of everything above, you should consider using a shell function rather than an alias for things like this