# EAPI 2

## Helpers

### doman

#### Recognition of Language Codes in File Names

Language codes in file names are now used for path translation.

##### Man Page Path Translation

Source | Destination
--- | ---
foo.1 | /usr/share/man/man1/foo.1
foo.lang.1 | /usr/share/man/lang/man1/foo.1

## Metadata

### Dependencies

#### Blocker Atoms

##### New Meaning for Old Syntax

Blocker atoms which use the previously existing !atom syntax now have a slightly different meaning. These blocker atoms indicate that conflicting packages may be temporarily installed simultaneously. When temporary simultaneous installation of conflicting packages occurs, the installation of a newer package may overwrite any colliding files that belong to an older package which is explicitly blocked. When such file collisions occur, the colliding files cease to belong to the older package, and they remain installed after the older package is eventually uninstalled. The older package is uninstalled only after any newer blocking packages have been merged on top of it.

##### New !!atom Syntax

A new !!atom syntax is now supported, for use in special cases for which temporary simultaneous installation of conflicting packages should not be allowed. If a given package happens to be blocked my a mixture of atoms consisting of both the !atom and !!atom syntaxes, the !!atom syntax takes precedence over the !atom syntax.

#### USE Dependencies

When used together with SLOT dependencies, USE dependencies appear on the right hand side of SLOT dependencies.

##### Unconditional USE Dependencies

###### Syntax Examples

Example | Meaning
--- | ---
foo[bar] | foo must have bar enabled
foo[bar,baz] | foo must have both bar and baz enabled
foo[-bar,baz] | foo must have bar disabled and baz enabled

##### Conditional USE Dependencies

###### Syntax Examples

Compact Form | Equivalent Expanded Form
--- | ---
foo[bar?] | bar? ( foo[bar] ) !bar? ( foo )
foo[!bar?] | bar? ( foo ) !bar? ( foo[-bar] )
foo[bar=] | bar? ( foo[bar] ) !bar? ( foo[-bar] )
foo[!bar=] | bar? ( foo[-bar] ) !bar? ( foo[bar] )

### SRC_URI

#### Customization of Output File Names

A new syntax is supported which allows customization of the output file name for a given URI. In order to customize the output file name, a given URI should be followed by a "->" operator which, in turn, should be followed by the desired output file name. As usual, all tokens, including the operator and output file name, should be separated by whitespace.

## Phases

### New src_prepare Phase Function

A new src_prepare function is called after the src_unpack function, with cwd initially set to $S.

### New src_configure Phase Function

The configure portion of the src_compile function has been split into a separate function which is named src_configure. The src_configure function is called in-between the src_prepare and src_compile functions.

    src_configure() {
    	if [[ -x ${ECONF_SOURCE:-.}/configure ]] ; then
    		econf
    	fi
    }

    src_compile() {
    	if [ -f Makefile ] || [ -f GNUmakefile ] || [ -f makefile ] ; then
    		emake || die "emake failed"
    	fi
    }

### Execution Order of Phase Functions

#### Execution Order of Phase Functions

Phase Function Name
pkg_setup
src_unpack
src_prepare
src_configure
src_compile
src_test
src_install
pkg_preinst
pkg_postinst
pkg_prerm
pkg_postrm

### Default Phase Functions

The default pkg_nofetch and src_* phase functions are now accessible via a function having a name that begins with default_ and ends with the respective phase function name. For example, a call to a function with the name default_src_compile is equivalent to a call to the default src_compile implementation.

#### Default Phase Functions

Function Name
default_pkg_nofetch
default_src_unpack
default_src_prepare
default_src_configure
default_src_compile
default_src_test

### Default Phase Function Alias

A function named "default" is redefined for each phase so that it will call the default_* function corresponding to the current phase. For example, a call to the function named "default" during the src_compile phase is equivalent to a call to the function named default_src_compile.