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both of which cause the file named filename to be read by
The expansion of
It is an error for an
include(`no-such-file') => error-->30.include:2: m4: Cannot open no-such-file: No such file or directory sinclude(`no-such-file') =>
Assume in the following that the file `incl.m4' contains the lines:
Include file start foo Include file end
Normally file inclusion is used to insert the contents of a file
into the input stream. The contents of the file will be read by
define(`foo', `FOO') => include(`incl.m4') =>Include file start =>FOO =>Include file end =>
The fact that
define(`bar', include(`incl.m4')) => This is `bar': >>>bar<<< =>This is bar: >>>Include file start =>foo =>Include file end =><<<
This use of
The builtin macros
If a file is not found in the current working directory, and the file name is not absolute, the file will be looked for in a specified search path. First, the directories specified with the `-I' option will be searched, in the order found on the command line. Second, if the `M4PATH' environment variable is set, it is expected to contain a colon-separated list of directories, which will be searched in order.
If the automatic search for include-files causes trouble, the `p' debug flag (see section Controlling debugging output) can help isolate the problem.