Bash script to manage per-project shell environment and other settings. Include in the project root, customize and source with the shell to activate. The rest of the boilerplate adds support for: * finding the absolute path of project root, independently of the current shell's working directory * a nice indicator with the project name to the pro…

project_env.sh

###############################################################################
# Development environment helper to set up project paths and other variables  #
###############################################################################
#
# Copyright (C) 2012 Andrea Ratto <andrearatto at yahoo dot it>. 
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
###############################################################################
# Usage                                                                       #
###############################################################################
#
# Add your project-specific environment configuration under the sections
# delimited by:
# "###PROJECT ENVIRONMENT SETUP###" and "###PROJECT ENVIRONMENT REVERT###"
#
# Then source this file with your normal bash shell, running
# . project_env.bash +
# or
# source project_env.bash +
#
# revert using "-" instead of "+" or just close the shell.
#
# Optionally add the following lines to your ~/.bashrc to get an alias
# "lastproject" to get quickly to the last project used.
#
## lastproject alias support start
#if [ -f ~/.lastproject.bash ]; then
#    . ~/.lastproject.bash
#fi
## lastproject alias support end
###############################################################################

function env_activate() {
    # available variables
    # $PROJECT_DIR: the absolute path of the folder containting this file
    #
    ###PROJECT ENVIRONMENT SETUP###
    
    #PROJECT_NAME="myproject" # defaults to the folder name if not set
    
    OLDPATH="$PATH"
    export PATH="$PROJECT_DIR/bin:$PATH"
    
    ###PROJECT ENVIRONMENT SETUP###
}

function env_deactivate() {
    ###PROJECT ENVIRONMENT REVERT###
    
    export PATH="$OLDPATH"
    unset OLDPATH
    
    ###PROJECT ENVIRONMENT REVERT###
}

# detect status and errors
case "$1" in
    +)
        ;;
    -)
        ;;
    *)
        echo "USAGE: source \"$BASH_SOURCE\" <+|->"
        return 1
        ;;
esac

_PROJECT_DIR="$(readlink -f "$(dirname "$BASH_SOURCE")")"
THIS_FILE="$(basename "$BASH_SOURCE")"

if [ ! -z "$PROJECT_DIR" ]; then
    if [ "$_PROJECT_DIR" != "$PROJECT_DIR" ]; then
        echo "Another project is active in the current shell. Deactivate with:"
        echo "source \"$_PROJECT_DIR/$THIS_FILE\" -"
        return 1
    else
        if [ $1 == "+" ]; then
            echo "This project is alredy active in the current shell. Optionally deactivate with:"
            echo "source \"$BASH_SOURCE\" -"
        return 1
        fi
    fi
else
    if [ $1 == "-" ]; then
        echo "This project is not active in the current shell. Nothing to do."
        return 1
    fi
fi

PROJECT_DIR="$_PROJECT_DIR"
unset _PROJECT_DIR

if [ $1 == "+" ]; then
    # Variable PROJECT_DIR is your reference to the full path of the folder
    # containing this file 
    PROJECT_NAME=$(basename "$PROJECT_DIR")

    env_activate

    OLDPS1="$PS1"
    PS1="[\$(if [[ \$? == 0 ]]; then echo \"\[\033[0;32m\]\"; else echo \"\[\033[0;31m\]\"; fi)$PROJECT_NAME\[\033[0m\]]$PS1"
    unset PROJECT_NAME
    # save the alias
    echo "alias lastproject='cd \"$PROJECT_DIR\"; source \"$THIS_FILE\" +'" \
        > ~/.lastproject.bash
else
    PS1="$OLDPS1"
    unset OLDPS1

    env_deactivate

    unset PROJECT_DIR
fi

unset THIS_FILE
return 0