File: autoconf.info,  Node: Existing Tests,  Next: Writing Tests,  Prev: Setup,  Up: Top

5 Existing Tests
****************

These macros test for particular system features that packages might
need or want to use.  If you need to test for a kind of feature that
none of these macros check for, you can probably do it by calling
primitive test macros with appropriate arguments (*note Writing
Tests::).

   These tests print messages telling the user which feature they're
checking for, and what they find.  They cache their results for future
‘configure’ runs (*note Caching Results::).

   Some of these macros set output variables.  *Note Makefile
Substitutions::, for how to get their values.  The phrase "define NAME"
is used below as a shorthand to mean "define the C preprocessor symbol
NAME to the value 1".  *Note Defining Symbols::, for how to get those
symbol definitions into your program.

* Menu:

* Common Behavior::             Macros' standard schemes
* Alternative Programs::        Selecting between alternative programs
* Files::                       Checking for the existence of files
* Libraries::                   Library archives that might be missing
* Library Functions::           C library functions that might be missing
* Header Files::                Header files that might be missing
* Declarations::                Declarations that may be missing
* Structures::                  Structures or members that might be missing
* Types::                       Types that might be missing
* Compilers and Preprocessors::  Checking for compiling programs
* System Services::             Operating system services
* C and Posix Variants::        Kludges for C and Posix variants
* Erlang Libraries::            Checking for the existence of Erlang libraries