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.

1 files changed, 11 insertions, 2 deletions

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) ;
 }