autoheader - creates a template file of C #define's for use by configure.
autoheader [ --help | -h ] [ --version | -V ] [ --verbose | -v ] [
--debug | -d ] [ --autoconf-dir=dir | -A dir ] [ --localdir=dir | -l
dir ] [ --warnings=category | -W category ]
The autoheader program can create a template file of C #define statements
for configure to use. If configure.ac invokes AC_CON-
FIG_HEADER(FILE), autoheader creates FILE.in; if multiple file arguments
are given, the first one is used. Otherwise, autoheader creates
If you give autoheader an argument, it uses that file instead of con-
figure.ac and writes the header file to the standard output instead of
to config.h.in. If you give autoheader an argument of -, it reads the
standard input instead of configure.ac and writes the header file to
the standard output.
autoheader scans configure.ac and figures out which C preprocessor symbols
it might define. It copies comments and #define and #undef statements
from a file called acconfig.h, which comes with and is installed
with Autoconf. It also uses a file called acconfig.h in the current
directory, if present. If you AC_DEFINE any additional symbols, you
must create that file with entries for them. For symbols defined by
AC_CHECK_HEADERS, AC_CHECK_FUNCS, AC_CHECK_SIZEOF, or AC_CHECK_LIB,
autoheader generates comments and #undef statements itself rather than
copying them from a file, since the possible symbols are effectively
The file that autoheader creates contains mainly #define and #undef
statements and their accompanying comments. If ./acconfig.h contains
the string @TOP@, autoheader copies the lines before the line containing
@TOP@ into the top of the file that it generates. Similarly, if
./acconfig.h contains the string @BOTTOM@, autoheader copies the lines
after that line to the end of the file it generates. Either or both of
those strings may be omitted.
An alternate way to produce the same effect is to create the files
FILE.top (typically config.h.top) and/or FILE.bot in the current directory.
If they exist, autoheader copies them to the beginning and end,
respectively, of its output. Their use is discouraged because they
have file names that contain two periods, and so can not be stored on
MS-DOS; also, they are two more files to clutter up the directory. But
if you use the --localdir=DIR option to use an acconfig.h in another
directory, they give you a way to put custom boilerplate in each individual
autoheader accepts the following options:
-h Print a summary of the command line options and exit.
-V Print the version number of Autoconf and exit.
-v Report processing steps.
-d Don't remove the temporary files.
-A dir Look for the installed macro files in directory dir. You can
also set the AC_MACRODIR environment variable to a directory;
this option overrides the environment variable.
-l dir Look for the package file aclocal.m4 in directory dir instead of
in the current directory.
Report the warnings related to category (which can actually be a
comma separated list). Special values for category include all
to report all warnings, none to report no warnings, and error to
treat warnings as errors. See the Texinfo documentation for a
list of categories and additional information.
autoconf(1), autoreconf(1), autoscan(1), autoupdate(1), ifnames(1)
David MacKenzie, with help from Franc,ois Pinard, Karl Berry, Richard
Pixley, Ian Lance Taylor, Roland McGrath, Noah Friedman, David D. Zuhn,
and many others. This manpage written by Ben Pfaff <firstname.lastname@example.org> for the Debian GNU/Linux autoconf package.
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