pushenv

README.md

pushenv

pushenv helps update your Bash or Zsh environment for compilation and linking with dependencies that are built and installed to different paths.

Installation

source pushenv.sh

Usage

pushenv PATH...

Example

Suppose you want to experiment with some C or C++ library whose source is freely available as a tar ball with an autoconf build system. You want the benefits of installing it without the drawbacks of mixing an experimental library into your standard system paths.

tar xzf niftywidgets-0.1.2.tgz
cd niftywidgets-0.1.2
./configure --prefix $HOME/local/niftywidgets-0.1.2
make install

Whenever you want to work with this library, first push compiler, linker, and man page environment variables into your current environment.

pushenv ~/local/niftywidgets-0.1.2

Voila! Plain old gcc and pkg-config commands work without hassle and you can lookup niftywidgets documentation with man.

pushenv.sh

pushenv() {

    # Path separator: a colon in Unix-like environments, a semi-
    # colon in Windows environments.
    SEP=":"

    maybe() {
        name=$1
        part=$(readlink -m $2)
        value=$3
        if ! [[ -d $part ]]; then
            # $part does not exist or is not a directory
            true
        elif [[ -z $value ]]; then
            echo "export $name=$part"
            export $name=$part
        elif ! [[ $value == "$part"
               || $value == "$part$SEP"*
               || $value == *"$SEP$part$SEP"*
               || $value == *"$SEP$part" ]]
        then
            echo "export $name=$part$SEP$value"
            export $name=$part$SEP$value
        fi
    }

    for dir in "$@"
    do
        maybe PATH            "$dir/bin"           "$PATH"
        maybe CPATH           "$dir/include"       "$CPATH"
        maybe LD_LIBRARY_PATH "$dir/lib"           "$LD_LIBRARY_PATH"
        maybe LIBRARY_PATH    "$dir/lib"           "$LIBRARY_PATH"
        maybe PKG_CONFIG_PATH "$dir/lib/pkgconfig" "$PKG_CONFIG_PATH"
    done
}