Chuse

Chuse stands for CHange USE. This is a Portage tool for managing your local USE flags (ie. set within /etc/portage/package.use).

In contrast to its several equivalents, it is designed with a very specific goal: Make your /etc/portage/package.use management easier. This means chuse does not handle other package.* and focuses on package.use. Indeed, I think you often have to deal with package.use and need a clean structure. On the other hand, you rarely have more than 10 lines in your package.mask, package.keywords... and open underlying files to read or edit them just work fine.

Installation

Chuse is available from the sapher overlay.

Once you have added this overlay through layman or whatever, just emerge chuse.

# emerge -av chuse

By default, chuse uses the following hierarchy pattern:

/etc/portage/package.use/<cat-name>/<pkg-name>

This file would contain each rules for the package in the category .

If you don't use this hierarchy pattern

If you want to use your own current pattern

You can toggle this default pattern by explicitely setting the PACKAGE_USE_FILE_PATTERN environment variable (eg. in your bashrc).

PACKAGE_USE_FILE_PATTERN examples:

PACKAGE_USE_FILE_PATTERN="/etc/portage/package.use" # All in one file
PACKAGE_USE_FILE_PATTERN="/etc/portage/package.use/%(cat)s" # One file per category
PACKAGE_USE_FILE_PATTERN="/etc/portage/package.use/%(cat)s/%(pkg)s" # This is the default
PACKAGE_USE_FILE_PATTERN="/etc/portage/package.use/chuse" # One file dedicated to chuse

%(cat)s and %(pkg)s would be respectively replaced by the category name and the package name of the atom you want to alter USE flags.

If you want to adopt this hierarchy pattern

You will have to backup your current USE flags in a file and reorganize the package.use hierarchy. To achieve this, issue the following commands:

# chuse --dump > /root/package.use.bak # Concat all your rules in one file
# chuse --load /root/package.use.bak # Export the backup to the new hierarchy

To avoid mistakes, chuse --load will ask you before erasing /etc/portage/package.use.

Usage

chuse <atom> [[modifier]<flag> ...] [(--because) <reason>]

atom:
    [version-selector]<ebuild-cat>/<ebuild-pkg>[-<version>][:<slot>]
    Obviously 'version-selector' and 'version' should never be set without the other.
version-selector:
    One of : "=", ">", "<", ">=", "<=".
ebuild-cat:
    An ebuild category (validity won't be checked).
ebuild-pkg:
    An ebuild package (validity won't be checked).
version:
    A version of the underlying package (validity won't be checked).
slot:
    A slot of the underlying package (validity won't be checked.
modifier:
    One of : "+", "-", "%" (% means reset default). If omitted, "+" is assumed.
flag:
    A USE flag (validity won't be checked).
reason:
    The reason why you changed these USE flags (so that you remember why you set this and if now
    you can reset default for instance).

If no flag is specified, this will display the current rules matching the underlying atom.

Examples

Add system-cairo, remove system-icu and reset system-jpeg for firefox >= 37.0.1:

$ sudo chuse ">=www-client/firefox-37.0.1" +system-cairo -system-icu %system-jpeg

Add offensive for sudo:

$ sudo chuse app-admin/sudo offensive --because much cooler

Show the flags you altered for sudo:

$ chuse app-admin/sudo
# [2015-04-18T11:54] Unset sendmail
# [2015-04-18T11:56] Set offensive
# much cooler
app-admin/sudo offensive -sendmail