check_unused_bash_completion.sh

#!/bin/bash

#
# check_unused_bash_completion.sh:
#   Checks unused bash_completion files and moves them into
#   /etc/bash_completion.d/unused/.
#

BASH_COMPLETION_DIR=/etc/bash_completion.d
BASH_COMPLETION_DIR_UNUSED="$BASH_COMPLETION_DIR/unused"

# This function checks whether we have a given program on the system.
# No need for bulky functions in memory if we don't.
#
have()
{
    unset -v have
    # Completions for system administrator commands are installed as well in
    # case completion is attempted via `sudo command ...'.
    PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin type $1 &>/dev/null &&
    have="yes"
}

if [ ! -d $BASH_COMPLETION_DIR_UNUSED ]; then
    mkdir $BASH_COMPLETION_DIR_UNUSED
fi

for i in $(LC_ALL=C command ls "$BASH_COMPLETION_DIR"); do
    unset -v have
    i=$BASH_COMPLETION_DIR/$i
    if [[ ${i##*/} != @(*~|*.bak|*.swp|\#*\#|*.dpkg*|*.rpm@(orig|new|save)|Makefile*) \
        && -f $i && -r $i ]]; then
        for j in $(grep -P '^\(?have' "$i" | grep -o -P '(?<=\bhave )[^ )]+'); do
            have "$j" && break
        done
        if [ "$have" = "yes" ]; then
            echo "$i: used"
        else
            echo "$i: unused"
            mv "$i" $BASH_COMPLETION_DIR_UNUSED
        fi
    fi
done