gistfile1.sh

gnu_utils=( awk find sed make tail )

case "$(uname)" in
  (SunOS)
    [[ -x /usr/gnu/bin/grep ]] ||
        rvm_error "ERROR: Missing '/usr/gnu/bin/grep', make sure it is installed before using RVM!"
    __rvm_grep()
    {
      GREP_OPTIONS="" /usr/gnu/bin/grep "$@" || return $?;
    }

    for gnu_util in "${gnu_utils[@]}"
    do
      [[ -x /usr/gnu/bin/$gnu_util ]] ||
        rvm_error "ERROR: Missing '/usr/gnu/bin/$gnu_util', make sure it is installed before using RVM!"
      eval "__rvm_$gnu_util() { /usr/gnu/bin/$gnu_util \"\$@\" || return \$?; }"
    done
    ;;
  (*)
    __rvm_grep()
    {
      GREP_OPTIONS="" \grep "$@" || return $?
    }
    
    for gnu_util in "${gnu_utils[@]}"
    do
      eval "__rvm_$gnu_util() { \\$gnu_util \"\$@\" || return \$?; }"
    done
    ;;
esac

unset gnu_util gnu_utils

the GREP_OPTIONS="" have to be on the same line with command, if it is on separate command then it is changed for the current subshell - which could influence other tools / scripts if any used:

 GREP_OPTIONS="" /usr/gnu/bin/grep "$@" || return $?;

and:

 GREP_OPTIONS="" \grep "$@" || return $?;

one more, in this:

for gnu_util in "${gnu_utils[@]}"
do
  eval "__rvm_$gnu_util() { \\$gnu_util \"\$@\" || return \$? }"
done

semicolon is missing:

for gnu_util in "${gnu_utils[@]}"
do
  eval "__rvm_$gnu_util() { \\$gnu_util \"\$@\" || return \$?; }"
done