If you are working with some software which requires you to source some code and messes up with your PATH and other environment variables like Vivado and Merlin compiler, here is a simple and straightforward method to get rid of the mess (to some extent).

#!/bin/bash
VERSION=2016.1
. /space/Xilinx/SDAccel/${VERSION}/settings64.sh
# do something if necessary
if ! test "$0" -ef "$(which $(basename $0))"
then
    exec $(basename $0) "$@"
else
    if test -t 2
    then
        echo "Recursive call detected!" 1&>2
    fi
fi

Some notes:

• Start with #!/bin/bash if you or your script use bash-specific syntax!
• Give this file execution permission with chmod +x!
• Make sure this file itself has the same name as the target program, or is soft-linked to it!
• Use . instead of source, which improves compatibility!