Add xaccess()

lib/functions.c

@@ -140,6 +140,11 @@ void xexec(char **argv)
 	error_exit("No %s", argv[0]);
 }
 
+void xaccess(char *path, int flags)
+{
+	if (access(path, flags)) error_exit("Can't access '%s'\n", path);
+}
+
 // Die unless we can open/create a file, returning file descriptor.
 int xcreate(char *path, int flags, int mode)
 {

lib/lib.h

@@ -38,6 +38,7 @@ void *xstrndup(char *s, size_t n);
 void *xstrdup(char *s);
 char *xmsprintf(char *format, ...);
 void xexec(char **argv);
+void xaccess(char *path, int flags);
 int xcreate(char *path, int flags, int mode);
 int xopen(char *path, int flags);
 FILE *xfopen(char *path, char *mode);