1 files changed, 26 insertions, 0 deletions
diff --git a/src/libs6/s6_instance_chdirservice.c b/src/libs6/s6_instance_chdirservice.c
new file mode 100644
index 0000000..356ee20
--- /dev/null
+++ b/src/libs6/s6_instance_chdirservice.c
@@ -0,0 +1,26 @@
+/* ISC license. */
+
+#include <string.h>
+#include <unistd.h>
+
+#include <skalibs/strerr.h>
+#include <skalibs/djbunix.h>
+
+#include <s6/supervise.h>
+
+void s6_instance_chdirservice (char const *s)
+{
+  int fd, r ;
+  size_t len = strlen(s) ;
+  char fn[len + 10] ;
+  if (!*s) strerr_dief1x(100, "invalid service path") ;
+  memcpy(fn, s, len) ;
+  memcpy(fn + len, "/instance", 10) ;
+  if (chdir(fn) == -1) strerr_diefu2sys(111, "chdir to ", fn) ;
+  fd = open_read(S6_SVSCAN_CTLDIR "/lock") ;
+  if (fd < 0) strerr_diefu3sys(111, "open ", fn, "/" S6_SVSCAN_CTLDIR "/lock") ;
+  r = fd_islocked(fd) ;
+  if (r < 0) strerr_diefu3sys(111, "check lock on ", fn, "/" S6_SVSCAN_CTLDIR "/lock") ;
+  if (!r) strerr_dief2x(1, "instanced service not running on ", s) ;
+  fd_close(fd) ;
+}