Where can I put a user-defined shell function?
Depends on the function. If it's just a super-simple one-liner like that you could create an alias or stick the function in ~/.bashrc
(a file that bash loads when it starts).
If you're creating something a bit more meaty, it might make more sense to create its own executable script in ~/bin/
which won't exist by default (it's just a directory) but should be in your path. Remember for this the file will need to be executable (chmod +x filename
) and start with a proper #!/bin/bash
stanza.
The second route has some clear benefits:
- It's easier to see what's available
- A syntax error won't tank your profile
- You don't need to keep re-sourcing your bash config if you change the script
- It's available to any shell as long as the full path is used or
~/bin/
is in the path for that shell too (which it should be in most cases AFAIK).
The best choice would be ~/.bashrc
file.
You can either write your shell function definitions directly in your ~/.bashrc
file, or, if you have lots of them and don't want to clutter your ~/.bashrc
file, you can put them all in another file of your choosing -- just be sure to source that file in your ~/.bashrc
file. For example, if the file with your functions is named bash_functions
, simply add in your ~/.bashrc
file the lines:
if [[ -f /path/to/bash_functions ]]; then
source /path/to/bash_functions
fi
or, equivalently:
if [[ -f /path/to/bash_functions ]]; then
. /path/to/bash_functions
fi
where the .
is just a symbolic representation of source
. The if
test makes sure the file /path/to/bash_functions
exists before trying to source it.
This technique is very similar to establishing aliases in ~/.bashrc
by creating a file called ~/.bash_aliases
and using similar syntax to that above in ~/.bashrc
to test for its existence and then source it.