Doc clarification, QoL fix for s6-usertree-maker

2 files changed, 25 insertions, 4 deletions

diff --git a/doc/s6-usertree-maker.html b/doc/s6-usertree-maker.html
index 4756006..847f04a 100644
--- a/doc/s6-usertree-maker.html
+++ b/doc/s6-usertree-maker.html
@@ -39,7 +39,7 @@ for the <a href="//skarnet.org/software/s6-rc/">s6-rc</a> service manager.
        [ -d <em>userscandir</em> ] \
        [ -p <em>path</em> ] \
        [ -E <em>envdir</em> [ -e <em>var</em> -e <em>var</em> ... ] ] \
-       [ -r <em>service</em>/<em>logger</em>/<em>pipeline</em> ] \
+       [ -r <em>service</em>/<em>logger</em>[/<em>pipeline</em>] ] \
        [ -l <em>loguser</em> ] \
        [ -t <em>stamptype</em> ] \
        [ -n <em>nfiles</em> ] \
@@ -208,7 +208,7 @@ then <a href="s6-svscan.html">s6-svscan</a> will be run on
 <tt>/home/ska/service</tt>.
 </p>
 
-<h2> Example </h2>
+<h2> Examples </h2>
 
 <pre>
      s6-usertree-maker -d '/run/user/${UID}/service' -p '${HOME}/bin:/usr/bin:/bin' -E /etc/user-env -e XDG_CONFIG_HOME -l catchlog ska /var/log/usertree/ska usertree-ska
@@ -225,6 +225,24 @@ as user catchlog, and storing its data in the <tt>/var/log/usertree/ska</tt>
 directory.
 </p>
 
+<p>
+ Note that simple quotes are used here to prevent the shell from
+interpreting <tt>${UID}</tt> and <tt>${HOME}</tt>.
+</p>
+
+<pre>
+     s6-usertree-maker -d '/run/user/${UID}/service' -p '${HOME}/bin:/usr/bin:/bin' -E /etc/user-env -e XDG_CONFIG_HOME -l catchlog -r usertree-ska/usertree-ska-log/usertree-ska-pipeline ska /var/log/usertree/ska usertree
+</pre>
+
+<p>
+ Same as above, except it does not create a service directory &mdash; instead, it
+creates a <tt>usertree</tt> directory containing two subdirectories: <tt>usertree-ska</tt>, the
+<a href="//skarnet.org/software/s6-rc/">s6-rc</a> source definition directory
+for the service, and <tt>usertree-ska-log</tt>, the source definition directory
+for its logger, and an implicit <tt>usertree-ska-pipeline</tt> bundle
+containing both the service and the logger.
+</p>
+
 <h2> Notes </h2>
 
 <ul>
diff --git a/src/usertree/s6-usertree-maker.c b/src/usertree/s6-usertree-maker.c
index 9326e82..26c4f1b 100644
--- a/src/usertree/s6-usertree-maker.c
+++ b/src/usertree/s6-usertree-maker.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/uio.h>
+#include <errno.h>
 
 #include <skalibs/config.h>
 #include <skalibs/uint64.h>
@@ -274,9 +275,8 @@ int main (int argc, char *const *argv)
   mask = umask(0) ;
   umask(mask) ;
   mask = ~mask & 0666 ;
-
-  if (mkdir(argv[2], 0755) < 0) strerr_diefu2sys(111, "mkdir ", argv[2]) ;
   dirlen = strlen(argv[2]) ;
+
   if (rcinfo[0])
   {
     size_t svclen = strlen(rcinfo[0]) ;
@@ -285,6 +285,8 @@ int main (int argc, char *const *argv)
     memcpy(dir, argv[2], dirlen) ;
     dir[dirlen] = '/' ;
     memcpy(dir + dirlen + 1, rcinfo[0], svclen + 1) ;
+    if (mkdir(argv[2], 0755) < 0 && errno != EEXIST)
+      strerr_diefu2sys(111, "mkdir ", argv[2]) ;
     if (mkdir(dir, 0755) < 0) strerr_diefu2sys(111, "mkdir ", dir) ;
     write_service(dir, argv[0], userscandir, rcinfo[1], path, userenvdir, vars, varlen) ;
     memcpy(dir + dirlen + 1, rcinfo[1], loglen + 1) ;
@@ -295,6 +297,7 @@ int main (int argc, char *const *argv)
     char dir[dirlen + 5] ;
     memcpy(dir, argv[2], dirlen) ;
     memcpy(dir + dirlen, "/log", 5) ;
+    if (mkdir(argv[2], 0755) < 0) strerr_diefu2sys(111, "mkdir ", argv[2]) ;
     write_service(argv[2], argv[0], userscandir, 0, path, userenvdir, vars, varlen) ;
     write_logger(dir, loguser, argv[1], stamptype, nfiles, filesize, maxsize, 0, 0) ;
   }