Make execline dependency optional

 This includes:
 - adding a configure option to disable execline support
 - duplicating el_semicolon() and el_getstrict() into the s6 library
when execline is disabled at build time, making a compat shim and
using it where needed (s6-svlisten, s6-ftrig-listen)
 - Creating alternatives for execlineb script spawning:
   * s6-log: '?' directive (done in the previous commit)
   * s6-notifyoncheck: require hardcoding the check in ./data/check
   * s6-ipcserver-access: no support for exec files, add a warning
 - Updating the relevant parts of the doc

 --enable-execline will remain the default, and whiners can choke
on their tears.

18 files changed, 183 insertions, 41 deletions

diff --git a/configure b/configure
index 3fc733a..7838b5b 100755
--- a/configure
+++ b/configure
@@ -46,6 +46,7 @@ Optional features:
   --enable-absolute-paths       do not rely on PATH to access this package's binaries,
                                   hardcode absolute BINDIR/foobar paths instead [disabled]
   --enable-nsss                 use the nsss library for user information [disabled]
+  --disable-execline            don't use the execline library [enabled]
 
 EOF
 exit 0
@@ -149,6 +150,7 @@ allpic=true
 slashpackage=false
 abspath=false
 usensss=false
+useexecline=true
 sproot=
 home=
 exthome=
@@ -192,6 +194,8 @@ for arg ; do
     --disable-absolute-paths|--enable-absolute-paths=no) abspath=false ;;
     --enable-nsss|--enable-nsss=yes) usensss=true ;;
     --disable-nsss|--enable-nsss=no) usensss=false ;;
+    --enable-execline|--enable-execline=yes) useexecline=true ;;
+    --disable-execline|--enable-execline=no) useexecline=false ;;
     --enable-*|--disable-*|--with-*|--without-*|--*dir=*) ;;
     --host=*|--target=*) target=${arg#*=} ;;
     --build=*) build=${arg#*=} ;;
@@ -448,6 +452,11 @@ else
   echo "LIBNSSS :="
   echo "MAYBEPTHREAD_LIB :="
 fi
+if $useexecline ; then
+  echo "LIBEXECLINE := -lexecline"
+else
+  echo "LIBEXECLINE :="
+fi
 
 exec 1>&3 3>&-
 echo "  ... done."
@@ -477,6 +486,11 @@ else
 fi
 echo "#define ${package_macro_name}_LIBEXECPREFIX \"$libexecdir/\""
 echo
+echo "#undef ${package_macro_name}_USE_EXECLINE"
+if $useexecline ; then
+  echo "#define ${package_macro_name}_USE_EXECLINE"
+fi
+echo
 echo "#endif"
 exec 1>&3 3>&-
 echo "  ... done."
diff --git a/doc/index.html b/doc/index.html
index 060f0ed..341a936 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -86,8 +86,11 @@ with s6</a> </li>
 2.9.1.0 or later. It's a build-time requirement. It's also a run-time
 requirement if you link against the shared version of the skalibs
 library. </li>
- <li> <a href="//skarnet.org/software/execline/">execline</a> version
-2.5.3.0 or later. It's a build-time and run-time requirement. </li>
+ <li> Optional: <a href="//skarnet.org/software/execline/">execline</a> version
+2.5.3.0 or later. When s6 is built with execline support (which is the default,
+execline is a build-time requirement, and also a run-time requirement for
+certain binaries that spawn scripts interpreted with
+<a href="//skarnet.org/software/execline/execlineb.html">execlineb</a>. </li>
 </ul>
 
 <h3> Licensing </h3>
diff --git a/doc/s6-ipcserver-access.html b/doc/s6-ipcserver-access.html
index b09d74a..2d35d84 100644
--- a/doc/s6-ipcserver-access.html
+++ b/doc/s6-ipcserver-access.html
@@ -168,7 +168,10 @@ is modified according to the contents of <tt>env</tt>. </li>
  <li> An <tt>exec</tt> file containing <em>newprog</em> completely
 bypasses the rest of s6-ipcserver-access' command line. After
 environment modifications, if any, s6-ipcserver-access execs into
-<tt><a href="//skarnet.org/software/execline/execlineb.html">execlineb</a> -c <em>newprog</em></tt>. </li>
+<tt><a href="//skarnet.org/software/execline/execlineb.html">execlineb</a> -c <em>newprog</em></tt>.
+Please be aware that the <tt>exec</tt> file functionality is only supported
+when s6 has been built with execline support. Otherwise, a warning message
+is printed and executable diversion is <em>not</em> performed. </li>
 </ul>
 
 </body>
diff --git a/doc/s6-log.html b/doc/s6-log.html
index 5cc4529..f042c70 100644
--- a/doc/s6-log.html
+++ b/doc/s6-log.html
@@ -234,14 +234,16 @@ padded with newlines so it is always <em>statussize</em> bytes long. 0 means
 an unpadded, unlimited status file. By default, <em>statussize</em> is 1001. </li>
  <li> <strong>!<em>processor</em></strong>: registers
 <tt>execlineb -Pc <em>processor</em></tt> as a processor for the next logdirs;
-<tt>execlineb</tt> must be found in s6-log's PATH.
+<tt>execlineb</tt> must be found in s6-log's PATH. This directive is only
+supported if s6 has been built with execline support; otherwise, it yields a
+syntax error at starting time.
 If <em>processor</em> is empty, no processor will be set for the next logdirs.
 By default, no processor is set. </li>
  <li> <strong>?<em>processor</em></strong>: registers
 <tt>/bin/sh -c <em>processor</em></tt> as a processor for the next logdirs.
 It is just like the <tt>!</tt> directive, except that the processor string
 is interpreted by <tt>/bin/sh</tt>, not <tt>execlineb</tt>. It is useful
-for people who have built s6 without execline support. </li>
+for people who want to build s6 without execline support. </li>
  <li> <strong>t</strong>: the logged line will be prepended with a
 <a href="//skarnet.org/software/skalibs/libstddjb/tai.html">TAI64N
 timestamp</a> (and a space) before being processed by the next action
diff --git a/doc/s6-notifyoncheck.html b/doc/s6-notifyoncheck.html
index 2b6bfc6..e154da0 100644
--- a/doc/s6-notifyoncheck.html
+++ b/doc/s6-notifyoncheck.html
@@ -114,7 +114,10 @@ instead of <tt>./data/check</tt>. The <em>checkprog</em> string will be parsed b
 can contain a full command line. This option is mainly useful is the program
 used to poll the service is very simple and can be inlined as a simple
 command line, to avoid needing to manage a whole script and a <tt>./data/check</tt>
-file. </li>
+file. This option is only supported if the
+<a href="//skarnet.org/software/execline/">execline</a> package is installed;
+if it is not, the <tt>-c</tt> option cannot be used and the checking
+script must always be placed in <tt>./data/check</tt>. </li>
 </ul>
 
 <h2> Usage </h2>
diff --git a/package/deps-build b/package/deps-build
index 1c19bb7..f276e1b 100644
--- a/package/deps-build
+++ b/package/deps-build
@@ -1,3 +1,3 @@
 /package/prog/skalibs
 /package/admin/nsss $usensss
-/package/admin/execline
+/package/admin/execline $useexecline
diff --git a/package/deps.mak b/package/deps.mak
index 0be7741..be31d08 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -2,8 +2,9 @@
 # This file has been generated by tools/gen-deps.sh
 #
 
+src/include/s6/compat.h: src/include/s6/config.h
 src/include/s6/ftrigr.h: src/include/s6/config.h
-src/include/s6/s6.h: src/include/s6/accessrules.h src/include/s6/ftrigr.h src/include/s6/ftrigw.h src/include/s6/s6-supervise.h src/include/s6/s6lock.h
+src/include/s6/s6.h: src/include/s6/accessrules.h src/include/s6/compat.h src/include/s6/ftrigr.h src/include/s6/ftrigw.h src/include/s6/s6-supervise.h src/include/s6/s6lock.h
 src/include/s6/s6lock.h: src/include/s6/config.h
 src/supervision/s6-svlisten.h: src/include/s6/ftrigr.h
 src/conn-tools/s6-accessrules-cdb-from-fs.o src/conn-tools/s6-accessrules-cdb-from-fs.lo: src/conn-tools/s6-accessrules-cdb-from-fs.c
@@ -11,7 +12,7 @@ src/conn-tools/s6-accessrules-fs-from-cdb.o src/conn-tools/s6-accessrules-fs-fro
 src/conn-tools/s6-connlimit.o src/conn-tools/s6-connlimit.lo: src/conn-tools/s6-connlimit.c
 src/conn-tools/s6-ioconnect.o src/conn-tools/s6-ioconnect.lo: src/conn-tools/s6-ioconnect.c
 src/conn-tools/s6-ipcclient.o src/conn-tools/s6-ipcclient.lo: src/conn-tools/s6-ipcclient.c
-src/conn-tools/s6-ipcserver-access.o src/conn-tools/s6-ipcserver-access.lo: src/conn-tools/s6-ipcserver-access.c src/include/s6/accessrules.h
+src/conn-tools/s6-ipcserver-access.o src/conn-tools/s6-ipcserver-access.lo: src/conn-tools/s6-ipcserver-access.c src/include/s6/accessrules.h src/include/s6/config.h
 src/conn-tools/s6-ipcserver-socketbinder.o src/conn-tools/s6-ipcserver-socketbinder.lo: src/conn-tools/s6-ipcserver-socketbinder.c
 src/conn-tools/s6-ipcserver.o src/conn-tools/s6-ipcserver.lo: src/conn-tools/s6-ipcserver.c src/include/s6/config.h
 src/conn-tools/s6-ipcserverd.o src/conn-tools/s6-ipcserverd.lo: src/conn-tools/s6-ipcserverd.c
@@ -22,7 +23,7 @@ src/daemontools-extras/s6-applyuidgid.o src/daemontools-extras/s6-applyuidgid.lo
 src/daemontools-extras/s6-envdir.o src/daemontools-extras/s6-envdir.lo: src/daemontools-extras/s6-envdir.c
 src/daemontools-extras/s6-envuidgid.o src/daemontools-extras/s6-envuidgid.lo: src/daemontools-extras/s6-envuidgid.c
 src/daemontools-extras/s6-fghack.o src/daemontools-extras/s6-fghack.lo: src/daemontools-extras/s6-fghack.c
-src/daemontools-extras/s6-log.o src/daemontools-extras/s6-log.lo: src/daemontools-extras/s6-log.c
+src/daemontools-extras/s6-log.o src/daemontools-extras/s6-log.lo: src/daemontools-extras/s6-log.c src/include/s6/config.h
 src/daemontools-extras/s6-setlock.o src/daemontools-extras/s6-setlock.lo: src/daemontools-extras/s6-setlock.c src/include/s6/config.h
 src/daemontools-extras/s6-setsid.o src/daemontools-extras/s6-setsid.lo: src/daemontools-extras/s6-setsid.c
 src/daemontools-extras/s6-setuidgid.o src/daemontools-extras/s6-setuidgid.lo: src/daemontools-extras/s6-setuidgid.c src/include/s6/config.h
@@ -39,6 +40,8 @@ src/fdholder/s6-fdholder-setdump.o src/fdholder/s6-fdholder-setdump.lo: src/fdho
 src/fdholder/s6-fdholder-store.o src/fdholder/s6-fdholder-store.lo: src/fdholder/s6-fdholder-store.c src/include/s6/s6-fdholder.h
 src/fdholder/s6-fdholder-transferdump.o src/fdholder/s6-fdholder-transferdump.lo: src/fdholder/s6-fdholder-transferdump.c src/include/s6/s6-fdholder.h
 src/fdholder/s6-fdholderd.o src/fdholder/s6-fdholderd.lo: src/fdholder/s6-fdholderd.c src/include/s6/accessrules.h src/include/s6/s6-fdholder.h
+src/instance/s6-instance-create.o src/instance/s6-instance-create.lo: src/instance/s6-instance-create.c
+src/instance/s6-instance-delete.o src/instance/s6-instance-delete.lo: src/instance/s6-instance-delete.c
 src/libs6/ftrig1_free.o src/libs6/ftrig1_free.lo: src/libs6/ftrig1_free.c src/libs6/ftrig1.h
 src/libs6/ftrig1_make.o src/libs6/ftrig1_make.lo: src/libs6/ftrig1_make.c src/libs6/ftrig1.h
 src/libs6/ftrigr1_zero.o src/libs6/ftrigr1_zero.lo: src/libs6/ftrigr1_zero.c src/include/s6/ftrigr.h
@@ -70,6 +73,7 @@ src/libs6/s6_accessrules_keycheck_uidgid.o src/libs6/s6_accessrules_keycheck_uid
 src/libs6/s6_accessrules_params_free.o src/libs6/s6_accessrules_params_free.lo: src/libs6/s6_accessrules_params_free.c src/include/s6/accessrules.h
 src/libs6/s6_accessrules_uidgid_cdb.o src/libs6/s6_accessrules_uidgid_cdb.lo: src/libs6/s6_accessrules_uidgid_cdb.c src/include/s6/accessrules.h
 src/libs6/s6_accessrules_uidgid_fs.o src/libs6/s6_accessrules_uidgid_fs.lo: src/libs6/s6_accessrules_uidgid_fs.c src/include/s6/accessrules.h
+src/libs6/s6_compat_el_semicolon.o src/libs6/s6_compat_el_semicolon.lo: src/libs6/s6_compat_el_semicolon.c src/include/s6/config.h
 src/libs6/s6_dtally_pack.o src/libs6/s6_dtally_pack.lo: src/libs6/s6_dtally_pack.c src/include/s6/s6-supervise.h
 src/libs6/s6_dtally_read.o src/libs6/s6_dtally_read.lo: src/libs6/s6_dtally_read.c src/include/s6/s6-supervise.h
 src/libs6/s6_dtally_unpack.o src/libs6/s6_dtally_unpack.lo: src/libs6/s6_dtally_unpack.c src/include/s6/s6-supervise.h
@@ -112,18 +116,18 @@ src/libs6/s6lock_zero.o src/libs6/s6lock_zero.lo: src/libs6/s6lock_zero.c src/in
 src/libs6/s6lockd-helper.o src/libs6/s6lockd-helper.lo: src/libs6/s6lockd-helper.c
 src/libs6/s6lockd.o src/libs6/s6lockd.lo: src/libs6/s6lockd.c src/include/s6/s6lock.h
 src/pipe-tools/s6-cleanfifodir.o src/pipe-tools/s6-cleanfifodir.lo: src/pipe-tools/s6-cleanfifodir.c src/include/s6/ftrigw.h
-src/pipe-tools/s6-ftrig-listen.o src/pipe-tools/s6-ftrig-listen.lo: src/pipe-tools/s6-ftrig-listen.c src/include/s6/ftrigr.h
+src/pipe-tools/s6-ftrig-listen.o src/pipe-tools/s6-ftrig-listen.lo: src/pipe-tools/s6-ftrig-listen.c src/include/s6/compat.h src/include/s6/ftrigr.h
 src/pipe-tools/s6-ftrig-listen1.o src/pipe-tools/s6-ftrig-listen1.lo: src/pipe-tools/s6-ftrig-listen1.c src/include/s6/ftrigr.h
 src/pipe-tools/s6-ftrig-notify.o src/pipe-tools/s6-ftrig-notify.lo: src/pipe-tools/s6-ftrig-notify.c src/include/s6/ftrigw.h
 src/pipe-tools/s6-ftrig-wait.o src/pipe-tools/s6-ftrig-wait.lo: src/pipe-tools/s6-ftrig-wait.c src/include/s6/ftrigr.h
 src/pipe-tools/s6-mkfifodir.o src/pipe-tools/s6-mkfifodir.lo: src/pipe-tools/s6-mkfifodir.c src/include/s6/ftrigw.h
-src/supervision/s6-notifyoncheck.o src/supervision/s6-notifyoncheck.lo: src/supervision/s6-notifyoncheck.c src/include/s6/ftrigr.h src/include/s6/s6-supervise.h
+src/supervision/s6-notifyoncheck.o src/supervision/s6-notifyoncheck.lo: src/supervision/s6-notifyoncheck.c src/include/s6/s6.h
 src/supervision/s6-permafailon.o src/supervision/s6-permafailon.lo: src/supervision/s6-permafailon.c src/include/s6/s6-supervise.h
 src/supervision/s6-supervise.o src/supervision/s6-supervise.lo: src/supervision/s6-supervise.c src/include/s6/ftrigw.h src/include/s6/s6-supervise.h
 src/supervision/s6-svc.o src/supervision/s6-svc.lo: src/supervision/s6-svc.c src/include/s6/config.h src/include/s6/s6-supervise.h
 src/supervision/s6-svdt-clear.o src/supervision/s6-svdt-clear.lo: src/supervision/s6-svdt-clear.c src/include/s6/s6-supervise.h
 src/supervision/s6-svdt.o src/supervision/s6-svdt.lo: src/supervision/s6-svdt.c src/include/s6/s6-supervise.h
-src/supervision/s6-svlisten.o src/supervision/s6-svlisten.lo: src/supervision/s6-svlisten.c src/supervision/s6-svlisten.h
+src/supervision/s6-svlisten.o src/supervision/s6-svlisten.lo: src/supervision/s6-svlisten.c src/supervision/s6-svlisten.h src/include/s6/compat.h
 src/supervision/s6-svlisten1.o src/supervision/s6-svlisten1.lo: src/supervision/s6-svlisten1.c src/supervision/s6-svlisten.h
 src/supervision/s6-svok.o src/supervision/s6-svok.lo: src/supervision/s6-svok.c src/include/s6/s6-supervise.h
 src/supervision/s6-svscan.o src/supervision/s6-svscan.lo: src/supervision/s6-svscan.c src/include/s6/config.h src/include/s6/s6-supervise.h
@@ -200,12 +204,12 @@ s6-fdholder-transferdump: src/fdholder/s6-fdholder-transferdump.o ${LIBS6}
 s6-fdholderd: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB}
 s6-fdholderd: src/fdholder/s6-fdholderd.o ${LIBS6}
 ifeq ($(strip $(STATIC_LIBS_ARE_PIC)),)
-libs6.a.xyzzy: src/libs6/ftrigr1_zero.o src/libs6/ftrigr_check.o src/libs6/ftrigr_checksa.o src/libs6/ftrigr_ack.o src/libs6/ftrigr_end.o src/libs6/ftrigr_start.o src/libs6/ftrigr_startf.o src/libs6/ftrigr_subscribe.o src/libs6/ftrigr_unsubscribe.o src/libs6/ftrigr_update.o src/libs6/ftrigr_updateb.o src/libs6/ftrigr_wait_and.o src/libs6/ftrigr_wait_or.o src/libs6/ftrigr_zero.o src/libs6/ftrigw_clean.o src/libs6/ftrigw_fifodir_make.o src/libs6/ftrigw_notify.o src/libs6/ftrigw_notifyb.o src/libs6/ftrigw_notifyb_nosig.o src/libs6/s6_accessrules_backend_cdb.o src/libs6/s6_accessrules_backend_fs.o src/libs6/s6_accessrules_keycheck_ip4.o src/libs6/s6_accessrules_keycheck_ip6.o src/libs6/s6_accessrules_keycheck_reversedns.o src/libs6/s6_accessrules_keycheck_uidgid.o src/libs6/s6_accessrules_params_free.o src/libs6/s6_accessrules_uidgid_cdb.o src/libs6/s6_accessrules_uidgid_fs.o src/libs6/s6_supervise_lock.o src/libs6/s6_supervise_lock_mode.o src/libs6/s6_dtally_pack.o src/libs6/s6_dtally_unpack.o src/libs6/s6_dtally_read.o src/libs6/s6_dtally_write.o src/libs6/s6_svc_lock_take.o src/libs6/s6_svc_lock_release.o src/libs6/s6_svc_ok.o src/libs6/s6_svc_write.o src/libs6/s6_svc_writectl.o src/libs6/s6_svstatus_pack.o src/libs6/s6_svstatus_read.o src/libs6/s6_svstatus_unpack.o src/libs6/s6_svstatus_write.o src/libs6/s6lock_acquire.o src/libs6/s6lock_check.o src/libs6/s6lock_end.o src/libs6/s6lock_release.o src/libs6/s6lock_start.o src/libs6/s6lock_startf.o src/libs6/s6lock_update.o src/libs6/s6lock_wait_and.o src/libs6/s6lock_wait_or.o src/libs6/s6lock_zero.o src/libs6/s6_fdholder_delete.o src/libs6/s6_fdholder_delete_async.o src/libs6/s6_fdholder_end.o src/libs6/s6_fdholder_getdump.o src/libs6/s6_fdholder_list.o src/libs6/s6_fdholder_list_async.o src/libs6/s6_fdholder_list_cb.o src/libs6/s6_fdholder_retrieve.o src/libs6/s6_fdholder_retrieve_async.o src/libs6/s6_fdholder_retrieve_cb.o src/libs6/s6_fdholder_setdump.o src/libs6/s6_fdholder_start.o src/libs6/s6_fdholder_store.o src/libs6/s6_fdholder_store_async.o
+libs6.a.xyzzy: src/libs6/ftrigr1_zero.o src/libs6/ftrigr_check.o src/libs6/ftrigr_checksa.o src/libs6/ftrigr_ack.o src/libs6/ftrigr_end.o src/libs6/ftrigr_start.o src/libs6/ftrigr_startf.o src/libs6/ftrigr_subscribe.o src/libs6/ftrigr_unsubscribe.o src/libs6/ftrigr_update.o src/libs6/ftrigr_updateb.o src/libs6/ftrigr_wait_and.o src/libs6/ftrigr_wait_or.o src/libs6/ftrigr_zero.o src/libs6/ftrigw_clean.o src/libs6/ftrigw_fifodir_make.o src/libs6/ftrigw_notify.o src/libs6/ftrigw_notifyb.o src/libs6/ftrigw_notifyb_nosig.o src/libs6/s6_accessrules_backend_cdb.o src/libs6/s6_accessrules_backend_fs.o src/libs6/s6_accessrules_keycheck_ip4.o src/libs6/s6_accessrules_keycheck_ip6.o src/libs6/s6_accessrules_keycheck_reversedns.o src/libs6/s6_accessrules_keycheck_uidgid.o src/libs6/s6_accessrules_params_free.o src/libs6/s6_accessrules_uidgid_cdb.o src/libs6/s6_accessrules_uidgid_fs.o src/libs6/s6_compat_el_semicolon.o src/libs6/s6_dtally_pack.o src/libs6/s6_dtally_unpack.o src/libs6/s6_dtally_read.o src/libs6/s6_dtally_write.o src/libs6/s6_supervise_lock.o src/libs6/s6_supervise_lock_mode.o src/libs6/s6_svc_lock_take.o src/libs6/s6_svc_lock_release.o src/libs6/s6_svc_ok.o src/libs6/s6_svc_write.o src/libs6/s6_svc_writectl.o src/libs6/s6_svstatus_pack.o src/libs6/s6_svstatus_read.o src/libs6/s6_svstatus_unpack.o src/libs6/s6_svstatus_write.o src/libs6/s6lock_acquire.o src/libs6/s6lock_check.o src/libs6/s6lock_end.o src/libs6/s6lock_release.o src/libs6/s6lock_start.o src/libs6/s6lock_startf.o src/libs6/s6lock_update.o src/libs6/s6lock_wait_and.o src/libs6/s6lock_wait_or.o src/libs6/s6lock_zero.o src/libs6/s6_fdholder_delete.o src/libs6/s6_fdholder_delete_async.o src/libs6/s6_fdholder_end.o src/libs6/s6_fdholder_getdump.o src/libs6/s6_fdholder_list.o src/libs6/s6_fdholder_list_async.o src/libs6/s6_fdholder_list_cb.o src/libs6/s6_fdholder_retrieve.o src/libs6/s6_fdholder_retrieve_async.o src/libs6/s6_fdholder_retrieve_cb.o src/libs6/s6_fdholder_setdump.o src/libs6/s6_fdholder_start.o src/libs6/s6_fdholder_store.o src/libs6/s6_fdholder_store_async.o
 else
-libs6.a.xyzzy: src/libs6/ftrigr1_zero.lo src/libs6/ftrigr_check.lo src/libs6/ftrigr_checksa.lo src/libs6/ftrigr_ack.lo src/libs6/ftrigr_end.lo src/libs6/ftrigr_start.lo src/libs6/ftrigr_startf.lo src/libs6/ftrigr_subscribe.lo src/libs6/ftrigr_unsubscribe.lo src/libs6/ftrigr_update.lo src/libs6/ftrigr_updateb.lo src/libs6/ftrigr_wait_and.lo src/libs6/ftrigr_wait_or.lo src/libs6/ftrigr_zero.lo src/libs6/ftrigw_clean.lo src/libs6/ftrigw_fifodir_make.lo src/libs6/ftrigw_notify.lo src/libs6/ftrigw_notifyb.lo src/libs6/ftrigw_notifyb_nosig.lo src/libs6/s6_accessrules_backend_cdb.lo src/libs6/s6_accessrules_backend_fs.lo src/libs6/s6_accessrules_keycheck_ip4.lo src/libs6/s6_accessrules_keycheck_ip6.lo src/libs6/s6_accessrules_keycheck_reversedns.lo src/libs6/s6_accessrules_keycheck_uidgid.lo src/libs6/s6_accessrules_params_free.lo src/libs6/s6_accessrules_uidgid_cdb.lo src/libs6/s6_accessrules_uidgid_fs.lo src/libs6/s6_supervise_lock.lo src/libs6/s6_supervise_lock_mode.lo src/libs6/s6_dtally_pack.lo src/libs6/s6_dtally_unpack.lo src/libs6/s6_dtally_read.lo src/libs6/s6_dtally_write.lo src/libs6/s6_svc_lock_take.lo src/libs6/s6_svc_lock_release.lo src/libs6/s6_svc_ok.lo src/libs6/s6_svc_write.lo src/libs6/s6_svc_writectl.lo src/libs6/s6_svstatus_pack.lo src/libs6/s6_svstatus_read.lo src/libs6/s6_svstatus_unpack.lo src/libs6/s6_svstatus_write.lo src/libs6/s6lock_acquire.lo src/libs6/s6lock_check.lo src/libs6/s6lock_end.lo src/libs6/s6lock_release.lo src/libs6/s6lock_start.lo src/libs6/s6lock_startf.lo src/libs6/s6lock_update.lo src/libs6/s6lock_wait_and.lo src/libs6/s6lock_wait_or.lo src/libs6/s6lock_zero.lo src/libs6/s6_fdholder_delete.lo src/libs6/s6_fdholder_delete_async.lo src/libs6/s6_fdholder_end.lo src/libs6/s6_fdholder_getdump.lo src/libs6/s6_fdholder_list.lo src/libs6/s6_fdholder_list_async.lo src/libs6/s6_fdholder_list_cb.lo src/libs6/s6_fdholder_retrieve.lo src/libs6/s6_fdholder_retrieve_async.lo src/libs6/s6_fdholder_retrieve_cb.lo src/libs6/s6_fdholder_setdump.lo src/libs6/s6_fdholder_start.lo src/libs6/s6_fdholder_store.lo src/libs6/s6_fdholder_store_async.lo
+libs6.a.xyzzy: src/libs6/ftrigr1_zero.lo src/libs6/ftrigr_check.lo src/libs6/ftrigr_checksa.lo src/libs6/ftrigr_ack.lo src/libs6/ftrigr_end.lo src/libs6/ftrigr_start.lo src/libs6/ftrigr_startf.lo src/libs6/ftrigr_subscribe.lo src/libs6/ftrigr_unsubscribe.lo src/libs6/ftrigr_update.lo src/libs6/ftrigr_updateb.lo src/libs6/ftrigr_wait_and.lo src/libs6/ftrigr_wait_or.lo src/libs6/ftrigr_zero.lo src/libs6/ftrigw_clean.lo src/libs6/ftrigw_fifodir_make.lo src/libs6/ftrigw_notify.lo src/libs6/ftrigw_notifyb.lo src/libs6/ftrigw_notifyb_nosig.lo src/libs6/s6_accessrules_backend_cdb.lo src/libs6/s6_accessrules_backend_fs.lo src/libs6/s6_accessrules_keycheck_ip4.lo src/libs6/s6_accessrules_keycheck_ip6.lo src/libs6/s6_accessrules_keycheck_reversedns.lo src/libs6/s6_accessrules_keycheck_uidgid.lo src/libs6/s6_accessrules_params_free.lo src/libs6/s6_accessrules_uidgid_cdb.lo src/libs6/s6_accessrules_uidgid_fs.lo src/libs6/s6_compat_el_semicolon.lo src/libs6/s6_dtally_pack.lo src/libs6/s6_dtally_unpack.lo src/libs6/s6_dtally_read.lo src/libs6/s6_dtally_write.lo src/libs6/s6_supervise_lock.lo src/libs6/s6_supervise_lock_mode.lo src/libs6/s6_svc_lock_take.lo src/libs6/s6_svc_lock_release.lo src/libs6/s6_svc_ok.lo src/libs6/s6_svc_write.lo src/libs6/s6_svc_writectl.lo src/libs6/s6_svstatus_pack.lo src/libs6/s6_svstatus_read.lo src/libs6/s6_svstatus_unpack.lo src/libs6/s6_svstatus_write.lo src/libs6/s6lock_acquire.lo src/libs6/s6lock_check.lo src/libs6/s6lock_end.lo src/libs6/s6lock_release.lo src/libs6/s6lock_start.lo src/libs6/s6lock_startf.lo src/libs6/s6lock_update.lo src/libs6/s6lock_wait_and.lo src/libs6/s6lock_wait_or.lo src/libs6/s6lock_zero.lo src/libs6/s6_fdholder_delete.lo src/libs6/s6_fdholder_delete_async.lo src/libs6/s6_fdholder_end.lo src/libs6/s6_fdholder_getdump.lo src/libs6/s6_fdholder_list.lo src/libs6/s6_fdholder_list_async.lo src/libs6/s6_fdholder_list_cb.lo src/libs6/s6_fdholder_retrieve.lo src/libs6/s6_fdholder_retrieve_async.lo src/libs6/s6_fdholder_retrieve_cb.lo src/libs6/s6_fdholder_setdump.lo src/libs6/s6_fdholder_start.lo src/libs6/s6_fdholder_store.lo src/libs6/s6_fdholder_store_async.lo
 endif
 libs6.so.xyzzy: EXTRA_LIBS := -lskarnet
-libs6.so.xyzzy: src/libs6/ftrigr1_zero.lo src/libs6/ftrigr_check.lo src/libs6/ftrigr_checksa.lo src/libs6/ftrigr_ack.lo src/libs6/ftrigr_end.lo src/libs6/ftrigr_start.lo src/libs6/ftrigr_startf.lo src/libs6/ftrigr_subscribe.lo src/libs6/ftrigr_unsubscribe.lo src/libs6/ftrigr_update.lo src/libs6/ftrigr_updateb.lo src/libs6/ftrigr_wait_and.lo src/libs6/ftrigr_wait_or.lo src/libs6/ftrigr_zero.lo src/libs6/ftrigw_clean.lo src/libs6/ftrigw_fifodir_make.lo src/libs6/ftrigw_notify.lo src/libs6/ftrigw_notifyb.lo src/libs6/ftrigw_notifyb_nosig.lo src/libs6/s6_accessrules_backend_cdb.lo src/libs6/s6_accessrules_backend_fs.lo src/libs6/s6_accessrules_keycheck_ip4.lo src/libs6/s6_accessrules_keycheck_ip6.lo src/libs6/s6_accessrules_keycheck_reversedns.lo src/libs6/s6_accessrules_keycheck_uidgid.lo src/libs6/s6_accessrules_params_free.lo src/libs6/s6_accessrules_uidgid_cdb.lo src/libs6/s6_accessrules_uidgid_fs.lo src/libs6/s6_supervise_lock.lo src/libs6/s6_supervise_lock_mode.lo src/libs6/s6_dtally_pack.lo src/libs6/s6_dtally_unpack.lo src/libs6/s6_dtally_read.lo src/libs6/s6_dtally_write.lo src/libs6/s6_svc_lock_take.lo src/libs6/s6_svc_lock_release.lo src/libs6/s6_svc_ok.lo src/libs6/s6_svc_write.lo src/libs6/s6_svc_writectl.lo src/libs6/s6_svstatus_pack.lo src/libs6/s6_svstatus_read.lo src/libs6/s6_svstatus_unpack.lo src/libs6/s6_svstatus_write.lo src/libs6/s6lock_acquire.lo src/libs6/s6lock_check.lo src/libs6/s6lock_end.lo src/libs6/s6lock_release.lo src/libs6/s6lock_start.lo src/libs6/s6lock_startf.lo src/libs6/s6lock_update.lo src/libs6/s6lock_wait_and.lo src/libs6/s6lock_wait_or.lo src/libs6/s6lock_zero.lo src/libs6/s6_fdholder_delete.lo src/libs6/s6_fdholder_delete_async.lo src/libs6/s6_fdholder_end.lo src/libs6/s6_fdholder_getdump.lo src/libs6/s6_fdholder_list.lo src/libs6/s6_fdholder_list_async.lo src/libs6/s6_fdholder_list_cb.lo src/libs6/s6_fdholder_retrieve.lo src/libs6/s6_fdholder_retrieve_async.lo src/libs6/s6_fdholder_retrieve_cb.lo src/libs6/s6_fdholder_setdump.lo src/libs6/s6_fdholder_start.lo src/libs6/s6_fdholder_store.lo src/libs6/s6_fdholder_store_async.lo
+libs6.so.xyzzy: src/libs6/ftrigr1_zero.lo src/libs6/ftrigr_check.lo src/libs6/ftrigr_checksa.lo src/libs6/ftrigr_ack.lo src/libs6/ftrigr_end.lo src/libs6/ftrigr_start.lo src/libs6/ftrigr_startf.lo src/libs6/ftrigr_subscribe.lo src/libs6/ftrigr_unsubscribe.lo src/libs6/ftrigr_update.lo src/libs6/ftrigr_updateb.lo src/libs6/ftrigr_wait_and.lo src/libs6/ftrigr_wait_or.lo src/libs6/ftrigr_zero.lo src/libs6/ftrigw_clean.lo src/libs6/ftrigw_fifodir_make.lo src/libs6/ftrigw_notify.lo src/libs6/ftrigw_notifyb.lo src/libs6/ftrigw_notifyb_nosig.lo src/libs6/s6_accessrules_backend_cdb.lo src/libs6/s6_accessrules_backend_fs.lo src/libs6/s6_accessrules_keycheck_ip4.lo src/libs6/s6_accessrules_keycheck_ip6.lo src/libs6/s6_accessrules_keycheck_reversedns.lo src/libs6/s6_accessrules_keycheck_uidgid.lo src/libs6/s6_accessrules_params_free.lo src/libs6/s6_accessrules_uidgid_cdb.lo src/libs6/s6_accessrules_uidgid_fs.lo src/libs6/s6_compat_el_semicolon.lo src/libs6/s6_dtally_pack.lo src/libs6/s6_dtally_unpack.lo src/libs6/s6_dtally_read.lo src/libs6/s6_dtally_write.lo src/libs6/s6_supervise_lock.lo src/libs6/s6_supervise_lock_mode.lo src/libs6/s6_svc_lock_take.lo src/libs6/s6_svc_lock_release.lo src/libs6/s6_svc_ok.lo src/libs6/s6_svc_write.lo src/libs6/s6_svc_writectl.lo src/libs6/s6_svstatus_pack.lo src/libs6/s6_svstatus_read.lo src/libs6/s6_svstatus_unpack.lo src/libs6/s6_svstatus_write.lo src/libs6/s6lock_acquire.lo src/libs6/s6lock_check.lo src/libs6/s6lock_end.lo src/libs6/s6lock_release.lo src/libs6/s6lock_start.lo src/libs6/s6lock_startf.lo src/libs6/s6lock_update.lo src/libs6/s6lock_wait_and.lo src/libs6/s6lock_wait_or.lo src/libs6/s6lock_zero.lo src/libs6/s6_fdholder_delete.lo src/libs6/s6_fdholder_delete_async.lo src/libs6/s6_fdholder_end.lo src/libs6/s6_fdholder_getdump.lo src/libs6/s6_fdholder_list.lo src/libs6/s6_fdholder_list_async.lo src/libs6/s6_fdholder_list_cb.lo src/libs6/s6_fdholder_retrieve.lo src/libs6/s6_fdholder_retrieve_async.lo src/libs6/s6_fdholder_retrieve_cb.lo src/libs6/s6_fdholder_setdump.lo src/libs6/s6_fdholder_start.lo src/libs6/s6_fdholder_store.lo src/libs6/s6_fdholder_store_async.lo
 s6-ftrigrd: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB}
 s6-ftrigrd: src/libs6/s6-ftrigrd.o src/libs6/ftrig1_free.o src/libs6/ftrig1_make.o
 s6lockd: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
@@ -214,8 +218,8 @@ s6lockd-helper: EXTRA_LIBS := -lskarnet
 s6lockd-helper: src/libs6/s6lockd-helper.o
 s6-cleanfifodir: EXTRA_LIBS := -lskarnet
 s6-cleanfifodir: src/pipe-tools/s6-cleanfifodir.o ${LIBS6}
-s6-ftrig-listen: EXTRA_LIBS := -lexecline -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
-s6-ftrig-listen: src/pipe-tools/s6-ftrig-listen.o ${LIBS6}
+s6-ftrig-listen: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
+s6-ftrig-listen: src/pipe-tools/s6-ftrig-listen.o ${LIBS6} ${LIBEXECLINE}
 s6-ftrig-listen1: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
 s6-ftrig-listen1: src/pipe-tools/s6-ftrig-listen1.o ${LIBS6}
 s6-ftrig-notify: EXTRA_LIBS := -lskarnet
@@ -236,8 +240,8 @@ s6-svdt: EXTRA_LIBS := -lskarnet
 s6-svdt: src/supervision/s6-svdt.o ${LIBS6}
 s6-svdt-clear: EXTRA_LIBS := -lskarnet
 s6-svdt-clear: src/supervision/s6-svdt-clear.o ${LIBS6}
-s6-svlisten: EXTRA_LIBS := -lexecline -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
-s6-svlisten: src/supervision/s6-svlisten.o src/supervision/s6_svlisten_signal_handler.o src/supervision/s6_svlisten_loop.o ${LIBS6}
+s6-svlisten: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
+s6-svlisten: src/supervision/s6-svlisten.o src/supervision/s6_svlisten_signal_handler.o src/supervision/s6_svlisten_loop.o ${LIBS6} ${LIBEXECLINE}
 s6-svlisten1: EXTRA_LIBS := -lskarnet ${SOCKET_LIB} ${SYSCLOCK_LIB} ${SPAWN_LIB}
 s6-svlisten1: src/supervision/s6-svlisten1.o src/supervision/s6_svlisten_signal_handler.o src/supervision/s6_svlisten_loop.o ${LIBS6}
 s6-svok: EXTRA_LIBS := -lskarnet
diff --git a/src/conn-tools/s6-ipcserver-access.c b/src/conn-tools/s6-ipcserver-access.c
index 9d78620..e3f6ac2 100644
--- a/src/conn-tools/s6-ipcserver-access.c
+++ b/src/conn-tools/s6-ipcserver-access.c
@@ -11,9 +11,14 @@
 #include <skalibs/env.h>
 #include <skalibs/djbunix.h>
 #include <skalibs/webipc.h>
-#include <execline/config.h>
+
+#include <s6/config.h>
 #include <s6/accessrules.h>
 
+#ifdef S6_USE_EXECLINE
+#include <execline/config.h>
+#endif
+
 #define USAGE "s6-ipcserver-access [ -v verbosity ] [ -e | -E ] [ -l localname ] [ -i rulesdir | -x rulesfile ] prog..."
 
 static unsigned int verbosity = 1 ;
@@ -204,9 +209,13 @@ int main (int argc, char const *const *argv, char const *const *envp)
   }
 
   if (params.exec.len)
+#ifdef S6_USE_EXECLINE
   {
     char *specialargv[4] = { EXECLINE_EXTBINPREFIX "execlineb", "-Pc", params.exec.s, 0 } ;
     xpathexec_r((char const *const *)specialargv, envp, env_len(envp), params.env.s, params.env.len) ;
   }
-  else xpathexec_r(argv, envp, env_len(envp), params.env.s, params.env.len) ;
+#else
+  strerr_warnw1x("exec file found but ignored because s6 was compiled without execline support!") ;
+#endif
+  xpathexec_r(argv, envp, env_len(envp), params.env.s, params.env.len) ;
 }
diff --git a/src/daemontools-extras/s6-log.c b/src/daemontools-extras/s6-log.c
index 6b2035e..54b945f 100644
--- a/src/daemontools-extras/s6-log.c
+++ b/src/daemontools-extras/s6-log.c
@@ -34,7 +34,11 @@
 #include <skalibs/skamisc.h>
 #include <skalibs/environ.h>
 
+#include <s6/config.h>
+
+#ifdef S6_USE_EXECLINE
 #include <execline/config.h>
+#endif
 
 #define USAGE "s6-log [ -d notif ] [ -q | -v ] [ -b ] [ -p ] [ -t ] [ -e ] [ -l linelimit ] logging_script"
 #define dieusage() strerr_dieusage(100, USAGE)
@@ -304,7 +308,11 @@ static int finish (logdir_t *ldp, char const *name, char suffix)
 
 static inline void exec_processor (logdir_t *ldp)
 {
+#ifdef S6_USE_EXECLINE
   char const *cargv[4] = { ldp->flags & 4 ? "/bin/sh" : EXECLINE_EXTBINPREFIX "execlineb", ldp->flags & 4 ? "-c" : "-Pc", ldp->processor, 0 } ;
+#else
+  char const *cargv[4] = { "/bin/sh", "-c", ldp->processor, 0 } ;
+#endif
   int fd ;
   PROG = "s6-log (processor child)" ;
   if (chdir(ldp->dir) < 0) strerr_diefu2sys(111, "chdir to ", ldp->dir) ;
@@ -713,7 +721,9 @@ static inline void script_firstpass (char const *const *argv, unsigned int *sell
       case 'r' :
       case 'E' :
       case '^' :
+#ifdef S6_USE_EXECLINE
       case '!' :
+#endif
       case '?' :
         break ;
       case 't' :
@@ -838,10 +848,12 @@ static inline void script_secondpass (char const *const *argv, scriptelem_t *scr
       case '^' :
         if (!uint0_scan(*argv + 1, &status_size)) goto fail ;
         break ;
+#ifdef S6_USE_EXECLINE
       case '!' :
         processor = (*argv)[1] ? *argv + 1 : 0 ;
         flags &= ~4 ;
         break ;
+#endif
       case '?' :
         processor = (*argv)[1] ? *argv + 1 : 0 ;
         flags |= 4 ;
diff --git a/src/include/s6/compat.h b/src/include/s6/compat.h
new file mode 100644
index 0000000..151db07
--- /dev/null
+++ b/src/include/s6/compat.h
@@ -0,0 +1,20 @@
+/* ISC license. */
+
+#ifndef S6_COMPAT_H
+#define S6_COMPAT_H
+
+#include <s6/config.h>
+
+#ifdef S6_USE_EXECLINE
+
+#include <execline/execline.h>
+#define s6_el_semicolon(argv) el_semicolon(argv)
+
+#else
+
+extern int s6_compat_el_semicolon (char const **) ;
+#define s6_el_semicolon(argv) s6_compat_el_semicolon(argv)
+
+#endif
+
+#endif
diff --git a/src/include/s6/s6.h b/src/include/s6/s6.h
index 98e23e1..aabcc13 100644
--- a/src/include/s6/s6.h
+++ b/src/include/s6/s6.h
@@ -3,6 +3,7 @@
 #ifndef S6_H
 #define S6_H
 
+#include <s6/compat.h>
 #include <s6/s6-supervise.h>
 #include <s6/ftrigr.h>
 #include <s6/ftrigw.h>
diff --git a/src/libs6/deps-lib/s6 b/src/libs6/deps-lib/s6
index 65612cc..ddd86dc 100644
--- a/src/libs6/deps-lib/s6
+++ b/src/libs6/deps-lib/s6
@@ -26,12 +26,13 @@ s6_accessrules_keycheck_uidgid.o
 s6_accessrules_params_free.o
 s6_accessrules_uidgid_cdb.o
 s6_accessrules_uidgid_fs.o
-s6_supervise_lock.o
-s6_supervise_lock_mode.o
+s6_compat_el_semicolon.o
 s6_dtally_pack.o
 s6_dtally_unpack.o
 s6_dtally_read.o
 s6_dtally_write.o
+s6_supervise_lock.o
+s6_supervise_lock_mode.o
 s6_svc_lock_take.o
 s6_svc_lock_release.o
 s6_svc_ok.o
diff --git a/src/libs6/s6_compat_el_semicolon.c b/src/libs6/s6_compat_el_semicolon.c
new file mode 100644
index 0000000..d6fdd06
--- /dev/null
+++ b/src/libs6/s6_compat_el_semicolon.c
@@ -0,0 +1,54 @@
+/* ISC license. */
+
+#include <s6/config.h>
+
+#ifndef S6_USE_EXECLINE
+
+#include <stdlib.h>
+
+#include <skalibs/types.h>
+#include <skalibs/strerr2.h>
+
+static unsigned int el_getstrict (void)
+{
+  static unsigned int strict = 0 ;
+  static int first = 1 ;
+  if (first)
+  {
+    char const *x = getenv("EXECLINE_STRICT") ;
+    first = 0 ;
+    if (x) uint0_scan(x, &strict) ;
+  }
+  return strict ;
+}
+
+int s6_compat_el_semicolon (char const **argv)
+{
+  static unsigned int nblock = 0 ;
+  int argc1 = 0 ;
+  nblock++ ;
+  for (;; argc1++, argv++)
+  {
+    char const *arg = *argv ;
+    if (!arg) return argc1 + 1 ;
+    if (!arg[0]) return argc1 ;
+    else if (arg[0] == ' ') ++*argv ;
+    else
+    {
+      unsigned int strict = el_getstrict() ;
+      if (strict)
+      {
+        char fmt1[UINT_FMT] ;
+        char fmt2[UINT_FMT] ;
+        fmt1[uint_fmt(fmt1, nblock)] = 0 ;
+        fmt2[uint_fmt(fmt2, (unsigned int)argc1)] = 0 ;
+        if (strict >= 2)
+          strerr_dief6x(100, "unquoted argument ", arg, " at block ", fmt1, " position ", fmt2) ;
+        else
+          strerr_warnw6x("unquoted argument ", arg, " at block ", fmt1, " position ", fmt2) ;
+      }
+    }
+  }
+}
+
+#endif
diff --git a/src/pipe-tools/deps-exe/s6-ftrig-listen b/src/pipe-tools/deps-exe/s6-ftrig-listen
index 0a30526..2d6e6d4 100644
--- a/src/pipe-tools/deps-exe/s6-ftrig-listen
+++ b/src/pipe-tools/deps-exe/s6-ftrig-listen
@@ -1,5 +1,5 @@
 ${LIBS6}
--lexecline
+${LIBEXECLINE}
 -lskarnet
 ${SOCKET_LIB}
 ${SYSCLOCK_LIB}
diff --git a/src/pipe-tools/s6-ftrig-listen.c b/src/pipe-tools/s6-ftrig-listen.c
index 993a914..d9c4b53 100644
--- a/src/pipe-tools/s6-ftrig-listen.c
+++ b/src/pipe-tools/s6-ftrig-listen.c
@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <signal.h>
 #include <unistd.h>
+
 #include <skalibs/sgetopt.h>
 #include <skalibs/types.h>
 #include <skalibs/strerr2.h>
@@ -12,7 +13,8 @@
 #include <skalibs/djbunix.h>
 #include <skalibs/sig.h>
 #include <skalibs/selfpipe.h>
-#include <execline/execline.h>
+
+#include <s6/compat.h>
 #include <s6/ftrigr.h>
 
 #define USAGE "s6-ftrig-listen [ -a | -o ] [ -t timeout ] fifodir1 regexp1 ... \"\" prog..."
@@ -56,7 +58,7 @@ int main (int argc, char const **argv, char const *const *envp)
     argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
   }
   if (argc < 4) dieusage() ;
-  argc1 = el_semicolon(argv) ;
+  argc1 = s6_el_semicolon(argv) ;
   if (!argc1 || (argc1 & 1) || (argc == argc1 + 1)) dieusage() ;
   if (argc1 >= argc) strerr_dief1x(100, "unterminated fifodir+regex block") ;
   tain_now_set_stopwatch_g() ;
diff --git a/src/supervision/deps-exe/s6-svlisten b/src/supervision/deps-exe/s6-svlisten
index fd153b3..a7bbbfa 100644
--- a/src/supervision/deps-exe/s6-svlisten
+++ b/src/supervision/deps-exe/s6-svlisten
@@ -1,7 +1,7 @@
 s6_svlisten_signal_handler.o
 s6_svlisten_loop.o
 ${LIBS6}
--lexecline
+${LIBEXECLINE}
 -lskarnet
 ${SOCKET_LIB}
 ${SYSCLOCK_LIB}
diff --git a/src/supervision/s6-notifyoncheck.c b/src/supervision/s6-notifyoncheck.c
index c8a0e19..b1ef96b 100644
--- a/src/supervision/s6-notifyoncheck.c
+++ b/src/supervision/s6-notifyoncheck.c
@@ -6,6 +6,7 @@
 #include <fcntl.h>
 #include <limits.h>
 #include <sys/wait.h>
+
 #include <skalibs/types.h>
 #include <skalibs/allreadwrite.h>
 #include <skalibs/bytestr.h>
@@ -15,11 +16,18 @@
 #include <skalibs/djbunix.h>
 #include <skalibs/selfpipe.h>
 #include <skalibs/iopause.h>
-#include <execline/config.h>
-#include <s6/s6-supervise.h>
-#include <s6/ftrigr.h>
 
+#include <s6/s6.h>
+
+#ifdef S6_USE_EXECLINE
+#include <execline/config.h>
 #define USAGE "s6-notifyoncheck [ -d ] [ -3 fd ] [ -s initialsleep ] [ -T globaltimeout ] [ -t localtimeout ] [ -w waitingtime ] [ -n tries ] [ -c \"checkprog...\" ] prog..."
+#define OPTIONS "d3:s:T:t:w:n:c:"
+#else
+#define USAGE "s6-notifyoncheck [ -d ] [ -3 fd ] [ -s initialsleep ] [ -T globaltimeout ] [ -t localtimeout ] [ -w waitingtime ] [ -n tries ] prog..."
+#define OPTIONS "d3:s:T:t:w:n:"
+#endif
+
 #define dieusage() strerr_dieusage(100, USAGE)
 
 
@@ -70,13 +78,14 @@ static int handle_event (ftrigr_t *a, uint16_t id, pid_t pid)
   return 0 ;
 }
 
-
 int main (int argc, char const *const *argv, char const *const *envp)
 {
   ftrigr_t a = FTRIGR_ZERO ;
   iopause_fd x[2] = { { .events = IOPAUSE_READ }, { .events = IOPAUSE_READ } } ;
-  char const *childargv[4] = { EXECLINE_EXTBINPREFIX "execlineb", "-Pc", 0, 0 } ;
+  char const *childargv[4] = { "./data/check", 0, 0, 0 } ;
+#ifdef S6_USE_EXECLINE
   char const *checkprog = 0 ;
+#endif
   unsigned int fd ;
   int df = 0 ;
   int autodetect = 1 ;
@@ -91,7 +100,7 @@ int main (int argc, char const *const *argv, char const *const *envp)
     unsigned int initialsleep = 10, globaltimeout = 0, localtimeout = 0, waitingtime = 1000 ;
     for (;;)
     {
-      int opt = subgetopt_r(argc, argv, "d3:s:T:t:w:n:c:", &l) ;
+      int opt = subgetopt_r(argc, argv, OPTIONS, &l) ;
       if (opt == -1) break ;
       switch (opt)
       {
@@ -102,7 +111,9 @@ int main (int argc, char const *const *argv, char const *const *envp)
         case 't' : if (!uint0_scan(l.arg, &localtimeout)) dieusage() ; break ;
         case 'w' : if (!uint0_scan(l.arg, &waitingtime)) dieusage() ; break ;
         case 'n' : if (!uint0_scan(l.arg, &tries)) dieusage() ; break ;
+#ifdef S6_USE_EXECLINE
         case 'c' : checkprog = l.arg ; break ;
+#endif
         default : dieusage() ;
       }
     }
@@ -124,12 +135,14 @@ int main (int argc, char const *const *argv, char const *const *envp)
     if (r < 0) strerr_diefu1sys(111, "sanity-check current service directory") ;
     if (!r) strerr_dief1x(100, "s6-supervise not running.") ;
   }
-  if (checkprog) childargv[2] = checkprog ;
-  else
+#ifdef S6_USE_EXECLINE
+  if (checkprog)
   {
-    childargv[0] = "./data/check" ;
-    childargv[1] = 0 ;
+    childargv[0] = EXECLINE_EXTBINPREFIX "execlineb" ;
+    childargv[1] = "-Pc" ;
+    childargv[2] = checkprog ;
   }
+#endif
 
   if (autodetect)
   {
diff --git a/src/supervision/s6-svlisten.c b/src/supervision/s6-svlisten.c
index c8af1f4..1364b44 100644
--- a/src/supervision/s6-svlisten.c
+++ b/src/supervision/s6-svlisten.c
@@ -1,13 +1,15 @@
 /* ISC license. */
 
 #include <stdint.h>
+
 #include <skalibs/sgetopt.h>
 #include <skalibs/types.h>
 #include <skalibs/bitarray.h>
 #include <skalibs/tai.h>
 #include <skalibs/strerr2.h>
 #include <skalibs/djbunix.h>
-#include <execline/execline.h>
+
+#include <s6/compat.h>
 #include "s6-svlisten.h"
 
 #define USAGE "s6-svlisten [ -U | -u | -d | -D | -r | -R ] [ -a | -o ] [ -t timeout ] servicedir... \"\" prog..."
@@ -46,8 +48,7 @@ int main (int argc, char const **argv, char const *const *envp)
     if (t) tain_from_millisecs(&tto, t) ; else tto = tain_infinite_relative ;
   }
   if (argc < 3) dieusage() ;
-
-  argc1 = el_semicolon(argv) ;
+  argc1 = s6_el_semicolon(argv) ;
   if (!argc1 || argc == argc1 + 1) dieusage() ;
   if (argc1 >= argc) strerr_dief1x(100, "unterminated servicedir block") ;
   if (wantrestart && or)