Add loopfiles() function, make catv use it.
diff --git a/lib/lib.h b/lib/lib.h
index 67c6dac..963abb6 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -73,6 +73,7 @@
 long atolx(char *c);
 off_t fdlength(int fd);
 char *xreadlink(char *name);
+void loopfiles(char **argv, void (*function)(int fd, char *name));
 
 // getmountlist.c
 struct mtab_list {