Mini Shell

#!/usr/bin/sh

# run vim if:
# - 'vi' command is used and 'vim' binary is available
# - 'vim' command is used
# NOTE: Set up a local alias if you want vim -> vi functionality. We will not
# do it globally, because it messes up with available startup options (see 
# ':help starting', 'vi' is not capable of '-d'). The introducing an environment
# variable, which an user must set to get the feature, will do the same trick
# as setting an alias (needs user input, does not work with sudo), so it is left
# on user whether he decides to use an alias:
#
# alias vim=vi
#
# in bashrc file.

if test -f /usr/bin/vim
then
  exec /usr/bin/vim "$@"
fi

# run vi otherwise
exec /usr/libexec/vi "$@"