nghttp2/doc/bash_completion/nghttpx

_nghttpx()
{
    local cur prev split=false
    COMPREPLY=()
    COMP_WORDBREAKS=${COMP_WORDBREAKS//=}

    cmd=${COMP_WORDS[0]}
    _get_comp_words_by_ref cur prev
    case $cur in
        -*)
            COMPREPLY=( $( compgen -W '--worker-read-rate --include --frontend-http2-dump-response-header --tls-ticket-key-file --verify-client-cacert --max-response-header-fields --backend-http2-window-size --tls13-client-ciphers --frontend-keep-alive-timeout --backend-request-buffer --max-request-header-fields --backend-connect-timeout --tls-max-proto-version --conf --dns-lookup-timeout --backend-http2-max-concurrent-streams --worker-write-burst --npn-list --dns-max-try --fetch-ocsp-response-file --tls-session-cache-memcached-cert-file --no-via --mruby-file --no-server-push --stream-read-timeout --client-ciphers --ocsp-update-interval --forwarded-for --accesslog-syslog --dns-cache-timeout --frontend-http2-read-timeout --listener-disable-timeout --ciphers --client-psk-secrets --strip-incoming-x-forwarded-for --no-server-rewrite --private-key-passwd-file --backend-keep-alive-timeout --backend-http-proxy-uri --frontend-max-requests --tls-no-postpone-early-data --rlimit-nofile --no-strip-incoming-x-forwarded-proto --tls-ticket-key-memcached-cert-file --no-verify-ocsp --forwarded-by --tls-session-cache-memcached-private-key-file --error-page --ocsp-startup --backend-write-timeout --tls-dyn-rec-warmup-threshold --frontend-http2-window-size --tls-ticket-key-memcached-max-retry --http2-no-cookie-crumbling --worker-read-burst --dh-param-file --accesslog-format --errorlog-syslog --redirect-https-port --request-header-field-buffer --api-max-request-body --frontend-http2-decoder-dynamic-table-size --errorlog-file --frontend-http2-max-concurrent-streams --psk-secrets --frontend-write-timeout --tls-ticket-key-cipher --read-burst --no-add-x-forwarded-proto --backend --server-name --insecure --backend-max-backoff --log-level --host-rewrite --tls-ticket-key-memcached-interval --frontend-http2-setting-timeout --frontend-http2-connection-window-size --worker-frontend-connections --syslog-facility --fastopen --no-location-rewrite --single-thread --no-http2-cipher-block-list --tls-session-cache-memcached --no-ocsp --backend-response-buffer --tls-min-proto-version --workers --add-x-forwarded-for --add-forwarded --worker-write-rate --add-request-header --backend-http2-settings-timeout --subcert --ignore-per-pattern-mruby-error --ecdh-curves --no-kqueue --help --frontend-frame-debug --tls-sct-dir --pid-file --frontend-http2-dump-request-header --daemon --write-rate --altsvc --backend-http2-decoder-dynamic-table-size --no-strip-incoming-early-data --user --verify-client-tolerate-expired --frontend-read-timeout --tls-ticket-key-memcached-max-fail --backlog --write-burst --backend-connections-per-host --tls-max-early-data --response-header-field-buffer --tls-ticket-key-memcached-address-family --padding --tls-session-cache-memcached-address-family --stream-write-timeout --cacert --tls-ticket-key-memcached-private-key-file --accesslog-write-early --backend-address-family --backend-http2-connection-window-size --tls13-ciphers --client-no-http2-cipher-block-list --version --add-response-header --backend-read-timeout --frontend-http2-optimize-window-size --frontend --accesslog-file --http2-proxy --backend-http2-encoder-dynamic-table-size --client-private-key-file --single-process --client-cert-file --tls-ticket-key-memcached --tls-dyn-rec-idle-timeout --frontend-http2-optimize-write-buffer-size --verify-client --frontend-http2-encoder-dynamic-table-size --read-rate --backend-connections-per-frontend --strip-incoming-forwarded ' -- "$cur" ) )
            ;;
        *)
            _filedir
            return 0
    esac
    return 0
}
complete -F _nghttpx nghttpx