---
page_title: pathexpand function reference
description: |-
  The `pathexpand` function replaces a leading tilde `~` character with the current user's
  home directory. Learn how to use the `pathexpand` function in Packer templates.
---

# `pathexpand` Function

`pathexpand` takes a filesystem path that might begin with a `~` segment,
and if so it replaces that segment with the current user's home directory
path.

This function works only with the path string and does not access the
filesystem itself. It is therefore unable to take into account filesystem
features such as symlinks.

If the leading segment in the path is not `~` then the given path is returned
unmodified.

Using this function in resource arguments will cause spurious diffs if the
same configuration is run by multiple users with different home directory
paths, or used on different host operating systems. We recommend using this
function only for transient values, such as in `connection` and `provisioner`
blocks to locate SSH keys, etc.

The rules for determining the "home directory" for the current user vary
depending on host operating system.

**For Unix systems**, the following sources are consulted, in order of preference:

- The `HOME` environment variable.
- The result of running `getent passwd` followed by the Packer process uid.
- The result of running `cd && pwd` in `sh`.

**For Windows systems**, there is not really the concept of a home directory
in the same sense as on Unix, but the following sources are consulted in
order of preference:

- The `HOME` environment variable.
- The `HOMEDRIVE` and `HOMEPATH` environment variables, if both are set.
- The `USERPROFILE` environment variable.

The exact rules employed for each operating system may change in future
releases of Packer.

## Examples

```shell-session
> pathexpand("~/.ssh/id_rsa")
/home/steve/.ssh/id_rsa
> pathexpand("/etc/resolv.conf")
/etc/resolv.conf
```
