.\" Copyright (C) 1992, 1993, 1994, 1995, 1996 Free Software Foundation, Inc.
.\" Copyright (C) 1998 Ben Pfaff.
.\"
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.\" this manual provided the copyright notice and this permission notice
.\" are preserved on all copies.
.\" 
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.\" manual under the conditions for verbatim copying, provided that the entire
.\" resulting derived work is distributed under the terms of a permission
.\" notice identical to this one.
.\" 
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.\" except that this permission notice may be stated in a translation approved
.\" by the Foundation.
.\"
.TH AUTOHEADER 1 "Autoconf"
.SH NAME
autoheader2.13 - creates a template file of C #define's for use by
configure.
.SH SYNOPSIS
.B autoheader2.13
[
.B --help
|
.B -h
] [
.B --localdir=dir
|
.B -l dir
] [
.B --macrodir=dir
|
.B -m dir
] [
.B --version
]
.SH DESCRIPTION
.PP
The 
.B autoheader2.13
program can create a template file of C 
.B #define
statements for 
.B configure
to use.  If 
.B configure.in
invokes
.BR AC_CONFIG_HEADER(FILE) , 
.B autoheader2.13
creates 
.BR FILE.in ; 
if multiple
file arguments are given, the first one is used.  Otherwise,
.B autoheader2.13
creates 
.BR config.h.in .
.PP
If you give 
.B autoheader2.13
an argument, it uses that file instead of
.B configure.in
and writes the header file to the standard output
instead of to 
.BR config.h.in .  
If you give 
.B autoheader2.13
an argument of
.BR - , 
it reads the standard input instead of 
.B configure.in
and writes
the header file to the standard output.
.PP
.B autoheader2.13
scans 
.B configure.in
and figures out which C
preprocessor symbols it might define.  It copies comments and 
.B #define
and 
.B #undef
statements from a file called 
.BR acconfig.h , 
which comes
with and is installed with Autoconf.  It also uses a file called
.B acconfig.h
in the current directory, if present.  If you 
.B AC_DEFINE
any additional symbols, you must create that file with entries for
them.  For symbols defined by 
.BR AC_CHECK_HEADERS , 
.BR AC_CHECK_FUNCS ,
.BR AC_CHECK_SIZEOF , 
or 
.BR AC_CHECK_LIB , 
.B autoheader2.13
generates comments
and 
.B #undef
statements itself rather than copying them from a file,
since the possible symbols are effectively limitless.
.PP
The file that 
.B autoheader2.13
creates contains mainly 
.B #define
and
.B #undef
statements and their accompanying comments.  If 
.B ./acconfig.h
contains the string 
.BR @TOP@ , 
.B autoheader2.13
copies the lines before the
line containing 
.B @TOP@
into the top of the file that it generates.
Similarly, if 
.B ./acconfig.h
contains the string 
.BR @BOTTOM@ ,
.B autoheader2.13
copies the lines after that line to the end of the file it
generates.  Either or both of those strings may be omitted.
.PP
An alternate way to produce the same effect is to create the files
.B FILE.top
(typically 
.BR config.h.top ) 
and/or 
.B FILE.bot
in the current
directory.  If they exist, 
.B autoheader2.13
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 
.B --localdir=DIR
option to use an 
.B acconfig.h
in
another directory, they give you a way to put custom boilerplate in each
individual 
.BR config.h.in .
.PP
.B autoheader2.13
accepts the following options:
.TP
.BI --help
.TP
.BI -h
Print a summary of the command line options and exit.
.TP
.BI --localdir=DIR
.TP
.BI -l\ DIR
Look for the package files 
.B aclocal.m4
and 
.B acconfig.h
(but not
.B FILE.top
and 
.BR FILE.bot ) 
in directory DIR instead of in the current
directory.
.TP
.BI --macrodir=DIR
.TP
.BI -m\ DIR
Look for the installed macro files and 
.B acconfig.h
in directory DIR.
You can also set the 
.B AC_MACRODIR
environment variable to a
directory; this option overrides the environment variable.
.TP
.BI --version
Print the version number of Autoconf and exit.
.SH "SEE ALSO"
.BR autoconf2.13 (1),
.BR autoreconf2.13 (1),
.BR autoscan2.13 (1),
.BR autoupdate2.13 (1),
.BR ifnames2.13 (1)
.SH AUTHORS
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
<pfaffben@debian.org> for the Debian GNU/Linux
.B autoconf2.13
package.