Create directory on-the-fly for pid file if it does not exist

index df9a641..6a0fbf6 100644
@@ -2545,6 +2545,7 @@ options_postprocess_mutate (struct options *o)
 #define CHKACC_FILEXSTWR (1<<2)  /** If file exists, is it writable? */
 #define CHKACC_INLINE (1<<3)     /** File is present if it's an inline file */
 #define CHKACC_ACPTSTDIN (1<<4)  /** If filename is stdin, it's allowed and "exists" */
+#define CHKACC_MKDIR (1<<5)      /** If directory is missing, create it on-the-fly */
 
 static bool
 check_file_access(const int type, const char *file, const int mode, const char *opt)

@@ -2571,8 +2572,14 @@ check_file_access(const int type, const char *file, const int mode, const char *
       char *fullpath = strdup(file);  /* POSIX dirname() implementaion may modify its arguments */
       char *dirpath = dirname(fullpath);
 
-      if (platform_access (dirpath, mode|X_OK) != 0)
+      if (platform_access (dirpath, mode|X_OK) != 0) {
+          /* If the directory does not exist, we might have been told to create it */
+          if (errno == ENOENT && (type & CHKACC_MKDIR)) {
+            mode_t dirmask =  (R_OK ? S_IRUSR : 0) | (W_OK ? S_IWUSR : 0 ) | S_IXUSR;
+            errno = (mkdir(dirpath, dirmask) == 0) ? 0 : errno;
+          }
           errcode = errno;
+      }
       free(fullpath);
     }
 

@@ -2738,7 +2745,7 @@ options_postprocess_filechecks (struct options *options)
   /* ** System related ** */
   errs |= check_file_access (CHKACC_FILE, options->chroot_dir,
                              R_OK|X_OK, "--chroot directory");
-  errs |= check_file_access (CHKACC_DIRPATH|CHKACC_FILEXSTWR, options->writepid,
+  errs |= check_file_access (CHKACC_DIRPATH|CHKACC_FILEXSTWR|CHKACC_MKDIR, options->writepid,
                              R_OK|W_OK, "--writepid");
 
   /* ** Log related ** */