More accurate exit code and clearer error messages for s6-svc and s6-svscanctl

1 files changed, 20 insertions, 1 deletions

diff --git a/src/libs6/s6_svc_writectl.c b/src/libs6/s6_svc_writectl.c
index b4d8e15..c522923 100644
--- a/src/libs6/s6_svc_writectl.c
+++ b/src/libs6/s6_svc_writectl.c
@@ -1,16 +1,35 @@
 /* ISC license. */
 
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
 #include <string.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-transactional.h>
 #include <s6/s6-supervise.h>
 
 int s6_svc_writectl (char const *service, char const *subdir, char const *s, size_t len)
 {
   size_t svlen = strlen(service) ;
   size_t sublen = strlen(subdir) ;
+  int r ;
   char fn[svlen + sublen + 10] ;
   memcpy(fn, service, svlen) ;
   fn[svlen] = '/' ;
   memcpy(fn + svlen + 1, subdir, sublen) ;
   memcpy(fn + svlen + 1 + sublen, "/control", 9) ;
-  return s6_svc_write(fn, s, len) ;
+  r = s6_svc_write(fn, s, len) ;
+  if (r != -2) return r ;
+
+  /* Now we need to investigate what went wrong... */
+  {
+    int fd, fdsub ;
+    fd = open(service, O_RDONLY | O_DIRECTORY) ;
+    if (fd < 0) return -1 ;
+    fdsub = open2_at(fd, subdir, O_RDONLY | O_DIRECTORY) ;
+    fd_close(fd) ;
+    if (fdsub < 0) return (errno == ENOENT) ? 0 : -2 ;
+    fd_close(fdsub) ;
+    return -2 ;
+  }
 }