Autotools Linux : Served On The Platter #2

Autotools are a great way of packaging binary applications in Linux.The autotools need to be installed by installing the auto-tools-dev and other dependencies.It uses the old Makefile way for compiling the program and checking dependencies. Here in this we take a sample C program depending on wxWidgets and openGL and build the install scripts using Autotools.Note that the directory structure is as follows :
|___Canvas
           |____src [ the source folder ]
           |         |__paint.cpp
           |____res [ the resources and data ]

Autotools uses a predefined directory for installing files and these directories are named in the autotools site.For eg. $PREFIX stands for /usr/local/ hence when you write your program make sure to use these locations.

Autoscan: We use an automated tool to generate the initial configure.scan script. In the root directory run 'autoscan' command.This will generate a configure.scan and a report there by traversing through all the directories for dependencies. Now rename this to 'configure.ac' and edit it as follows.

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.

AC_PREREQ([2.69])
AC_INIT([canvas], [1.0], [saswat.cs11@iitp.ac.in])
AM_INIT_AUTOMAKE([-Wall foreign])
AC_CONFIG_SRCDIR([src/paint.cpp])
AC_CONFIG_HEADERS([config.h])

# Checks for programs.
AC_PROG_CXX

# Checks for libraries.
AM_OPTIONS_WXCONFIG
reqwx=2.4.0
AM_PATH_WXCONFIG($reqwx, wxWin=1)
if test "$wxWin" != 1; then
 AC_MSG_ERROR([
  wxWidgets must be installed on your system.
 
  Please check that wx-config is in path, the directory
  where wxWidgets libraries are installed (returned by
  'wx-config --libs' or 'wx-config --static --libs' command)
  is in LD_LIBRARY_PATH or equivalent variable and
  wxWidgets version is $reqwx or above.
  ])
fi
 
CPPFLAGS="$CPPFLAGS $WX_CPPFLAGS"
CXXFLAGS="$CXXFLAGS $WX_CXXFLAGS_ONLY"
CFLAGS="$CFLAGS $WX_CFLAGS_ONLY"
LIBS="$LIBS $WX_LIBS -lGL -lGLU -lglut `wx-config --gl-libs`"

# Checks for header files.

# Checks for typedefs, structures, and compiler characteristics.
AC_CHECK_HEADER_STDBOOL

# Checks for library functions.
AC_FUNC_MALLOC


AC_OUTPUT(Makefile src/Makefile res/Makefile)

Now notice the Macros in the section.AC_INIT initialize the package name and version and bug to send mail.AC_PROG_CXX checks for C++ in the system.We then check for wxWidgets in the system.This is present in their wiki for code above.Next add the FLAGS for compilation of librariesAC_OUTPUT checks for the Makefiles that should be generated as mentioned in brackets.Each must have a Makefile.am ready in them.

MAKEFILES: Each makefile.am should be as follows.In the source directory the Makefile is as follows:

bin_PROGRAMS = canvas
canvas_SOURCES = paint.cpp

The bin_PROGRAMS specifies the following binaries to be compiled and stored in the $PREFIX/bin directory.The _SOURCES specify the sources of the binaries.For the data directory the makefile should be as follows:

resdir = $(datarootdir)/@PACKAGE@
res_DATA = canvas.png chk.png crop.png curve.png erase.png ...

 We define a data directory according to the one used in the binary and the data files will be written to it.

COMMANDS: Once these files are ready run the following commands in order:
* aclocal
* automake --add-missing
* autoconf
* autoreconf -fvi
You will get your scripts.Run configure and make install to install.This project can be found in my github account :  https://github.com/saswatraj/Canvas