Check unused bash_completion files

check_unused_bash_completion.sh

#!/bin/bash

#
# check_unused_bash_completion.sh
#
# Check unused bash_completion files and moves them into "unused"
# subdirectory.  Loading many completion files makes Cygwin/MSYS bash
# very slow.
#

if [ -d /etc/bash_completion.d ]; then
    # Cygwin
    BASH_COMPLETION_DIR=/etc/bash_completion.d
elif [ -d /usr/share/bash-completion/completions ]; then
    # MSYS2
    BASH_COMPLETION_DIR=/usr/share/bash-completion/completions
else
    echo 'completion dir not found' 1>&2
    exit 1
fi

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
    if [[ $1 = @(bash-builtins|configure) ]]; then
        have="yes"
        return
    fi
    # Completions for system administrator commands are installed as well in
    # case completion is attempted via `sudo command ...'.
    PATH=$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
    j=$BASH_COMPLETION_DIR/$i
    if [[ ${j##*/} != @(*~|*.bak|*.swp|\#*\#|*.dpkg*|*.rpm@(orig|new|save)|Makefile*) \
            && -f $j && -r $j ]]; then
        have "$i" || have "${i%-completion}" || \
        for k in $(grep -P '^\(?have' "$j" | grep -o -P '(?<=\bhave )[^ )]+'); do
            have "$k" && break
        done
        if [ "$i" = "mercurial" ]; then
            have hg
        fi
        if [ "$have" = "yes" ]; then
            echo -e "$j: \e[32mused\e[m"
        else
            echo -e "$j: \e[31munused\e[m"
            mv "$j" $BASH_COMPLETION_DIR_UNUSED
        fi
    fi
done