1 files changed, 26 insertions, 0 deletions
diff --git a/src/serverlib/s6rc_livedir_prefixsize.c b/src/serverlib/s6rc_livedir_prefixsize.c
new file mode 100644
index 0000000..d897fe6
--- /dev/null
+++ b/src/serverlib/s6rc_livedir_prefixsize.c
@@ -0,0 +1,26 @@
+/* ISC license. */
+
+#include <limits.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <s6-rc/s6rc-utils.h>
+
+int s6rc_livedir_prefixsize (char const *live, size_t *n)
+{
+  struct stat st ;
+  size_t llen = strlen(live) ;
+  char sfn[llen + 8] ;
+  memcpy(sfn, live, llen) ;
+  memcpy(sfn + llen, "/prefix", 8) ;
+  if (stat(sfn, &st) < 0)
+  {
+    if (errno != ENOENT) return 0 ;
+    *n = 0 ;
+    return 1 ;
+  }
+  if (!S_ISREG(st.st_mode)) return (errno = EINVAL, 0) ;
+  if (st.st_size > PATH_MAX) return (errno = ENAMETOOLONG, 0) ;
+  *n = st.st_size ;
+  return 1 ;
+}