plan, plan_lazy

(Set TAP test suite plan)


#include <tap/basic.h>

void plan(unsigned long count);

void plan_lazy(void);


plan() sets up a TAP test plan and prints out the initial output line that tells the harness how many tests are expected. It also sets up some internal tracking in the TAP library, such as initializing the test number and preparing to track how many tests succeeded and failed. It should be called before performing any tests, and takes the number of tests that will be performed.

plan_lazy() is identical to plan() except that it does not specify the number of tests to be performed. Instead, the library will automatically print out a plan line when the tests are complete, making the assumption that the number of tests run was the number of tests planned. This is not the recommended approach for writing tests since, should the test program exit in the middle for some reason, everything will appear to succeed. But it can save time in writing test cases quickly and can make it easier to write test cases where the number of tests are not known in advance.

After one of these functions has been called, the current test number, maintained internally by the TAP library, is available as the global variable testnum. If the test case must report test results without using the TAP library functions, it can manipulate the testnum variable directly to maintain proper test numbering, but be aware that doing so will cause the test summary reported at the end of the test case to be incorrect.




Only one of plan() or plan_lazy() should be called for a given test suite, and one of them should be called before any tests are performed and before any other TAP library functions except skip_all() are called.


Russ Allbery <>


Copyright 2010, 2013 Russ Allbery <>

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. This file is offered as-is, without any warranty.

SPDX-License-Identifier: FSFAP


bail(3), diag(3), is_int(3), ok(3), skip(3), skip_all(3)

The current version of the C TAP Harness library is available from its web page at <>.

Last modified and spun 2018-05-06