I still cannot believe how easy it is to embed Bash tab completion into
the script that needs it. I really wish more people did it. It saves all
the hassle of extra installations into whatever bash_completion.d
directory and removes need for shitty eval calls in .bashrc files
(like Cobra and others require).
Here’s an example that combines completion of command actions with
another list that simulates a bunch of possibilities. (I use something
like this in sshkey to complete either all the public key names or the
commands.)
#!/bin/sh
cmds="help usage"
help() {
echo "would print help"
}
usage() {
echo "usage: foo [COMMAND|name] [OPTIONS]"
}
list() {
printf "one\ntwo\nthree"
}
default() {
echo "default command"
}
# ---------------------- bash completion context ---------------------
# add `complete -S foo foo` to bashrc
if test -n "${COMP_LINE}"; then
pre="${COMP_LINE##* }"
for c in ${cmds:+${cmds} $(list)}; do
test -z "${pre}" -o "${c}" != "${c#${pre}}" && echo "$c"
done
exit
fi
# ------------------------------- main -------------------------------
cmd="$1"
test $# -gt 0 && shift
case "$cmd" in
ls | list) list "$@" ;;
*) default "$@" ;;
esac