Standards-specified location for user configuration files

configurationdirectory-structurehome

I'm talking about files like ~/.foo found on a user's home dir. I'm working on a program that reads from such a file, and I'd also like to clean up my user root directory if I can.

Is there a POSIX-specified variable, such as ~/$(conf) where config like .emacs can be found?

Best Answer

POSIX

Searching through the specification for the strings "user config" or "configuration files" turned up zero hits, so I would say no it doesn't specify this in any way.

http://pubs.opengroup.org/onlinepubs/9699919799/

FHS

Looking at the FHS - Filesystem Hierarchy Standard it had this bit:

User specific configuration files for applications are stored in the user's home directory in a file that starts with the '.' character (a "dot file"). If an application needs to create more than one dot file then they should be placed in a subdirectory with a name starting with a '.' character, (a "dot directory"). In this case the configuration files should not start with the '.' character. 11.

sysconf/getconf

Looking through the list of POSIX configuration constants present in <limits.h> is the only other place I can think of where something like this would be configured. Running the command getconf <var> will return these types of results.

For example:

$ getconf _POSIX_CHILD_MAX
1024

But looking through the list of definitions I don't see any pertaining to a user's home directory.

Related Solutions

Use non-root user configuration for root account

Use sudo -E to preserve your environment:

$ export FOO=1
$ sudo -E env | grep FOO
FOO=1

That will preserve $HOME and any other environment variables you had, so the same configuration files you started with will be accessed by the programs running as root.

You can update sudoers to disable the env_reset setting, which clears out all environment variables and is generally enabled by default. You may have to enable the ability to use sudo -E at all in there as well. There are a few other sudoers settings that might be relevant: env_keep, which lets you specify specific variables to keep by default, and env_remove, which declares variables to delete always. You can use sudo sudo -V to see which variables are/are not preserved.

An alternative, if you can't modify sudoers, is to provide your environment explicitly:

sudo env HOME=$HOME command here

You can make a shell alias to do that automatically so you don't have to type it in.

Note that doing this (either way) can have potentially unwanted side effects: if the program you run tries to make files in your home directory, for example, those files will be created as root and your ordinary user won't be able to write to them.

For the specific case of vim, you could also put your .vimrc as the system-wide /etc/vimrc if you're the only user of this system.

Linux – ssh via public key if there is no home directory on the remote system

Assuming your username is testssh:

create /etc/ssh/authorized_keys_testssh and put your key there
add the following in /etc/ssh/sshd_config:

Match User testssh
    AuthorizedKeysFile  /etc/ssh/authorized_keys_%u

and restart sshd. Your user will be able to ssh with his private key.