BASH coding

bash.sh

# To check if a directory exists in a bash shell script you can use the following:
if [ -d "$DIRECTORY" ]; then
    # Control will enter here if $DIRECTORY exists
fi

# Or to check if a directory doesn't exist:
if [ ! -d "$DIRECTORY" ]; then
    # Control will enter here if $DIRECTORY doesn't exist
fi

# Search for string in a file
if grep -q PATTERN FILE; then
    echo "Found"
fi

# http://en.wikipedia.org/wiki/Here_document#Unix-Shells