<br />
<b>Warning</b>:  Declaration of action_plugin_subjectindex_indexer::register(&$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/subjectindex/action/indexer.php</b> on line <b>15</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_mathjax_enable::register(Doku_Event_Handler &$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/mathjax/action/enable.php</b> on line <b>62</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_googleanalytics::register(&$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/googleanalytics/action.php</b> on line <b>40</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_folded::register(&$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/folded/action.php</b> on line <b>40</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_hidden::register(&$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/hidden/action.php</b> on line <b>28</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_include::register(&$controller) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/include/action.php</b> on line <b>354</b><br />
<br />
<b>Warning</b>:  Declaration of action_plugin_tag::register(&$contr) should be compatible with DokuWiki_Action_Plugin::register(Doku_Event_Handler $controller) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/tag/action.php</b> on line <b>175</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/subjectindex/action/indexer.php:15) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/inc/auth.php</b> on line <b>532</b><br />
<br />
<b>Warning</b>:  preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/inc/auth.php</b> on line <b>818</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/subjectindex/action/indexer.php:15) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/inc/actions.php</b> on line <b>656</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/subjectindex/action/indexer.php:15) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/inc/actions.php</b> on line <b>656</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /data/web/virtuals/28604/virtual/www/subdom/bo/lib/plugins/subjectindex/action/indexer.php:15) in <b>/data/web/virtuals/28604/virtual/www/subdom/bo/inc/actions.php</b> on line <b>656</b><br />

======Exercise 2: Make Is Your Python Now======

   In Python you ran programs by just typing python and the code you
   wanted to run. The Python interpreter would just run them, and import
   any other libraries and things you needed on the fly as it ran. C is a
   different beast completely where you have to compile your source files
   and manually stitch them together into a binary that can run on its
   own. Doing this manually is a pain, and in the last exercise you just
   ran make to do it.

   In this exercise, you're going to get a crash course in GNU make, and
   you'll be learning to use it as you learn C. Make will for the rest of
   this book, be your Python. It will build your code, and run your tests,
   and set things up and do all the stuff for you that Python normally
   does.

   The difference is, I'm going to show you smarter Makefile wizardry,
   where you don't have to specify every stupid little thing about your C
   program to get it to build. I won't do that in this exercise, but after
   you've been using "baby make" for a while, I'll show you "master make".

======Using Make======

   The first stage of using make is to just use it to build programs it
   already knows how to build. Make has decades of knowledge on building a
   wide variety of files from other files. In the last exercise you did
   this already using commands like this:
$ make ex1
# or this one too
$ CFLAGS="-Wall" make ex1

   In the first command you're telling make, "I want a file named ex1 to
   be created." Make then does the following:
     * Does the file ex1 exist already?
     * No. Ok, is there another file that starts with ex1?
     * Yes, it's called ex1.c. Do I know how to build .c files?
     * Yes, I run this command cc ex1.c   -o ex1 to build them.
     * I shall make you one ex1 by using cc to build it from ex1.c.

   The second command in the listing above is a way to pass "modifiers" to
   the make command. If you're not familiar with how the Unix shell works,
   you can create these "environment variables" which will get picked up
   by programs you run. Sometimes you do this with a command like export
   CFLAGS="-Wall" depending on the shell you use. You can however also
   just put them before the command you want to run, and that environment
   variable will be set only while that command runs.

   In this example I did CFLAGS="-Wall" make ex1 so that it would add the
   command line option -Wall to the cc command that make normally runs.
   That command line option tells the compiler cc to report all warnings
   (which in a sick twist of fate isn't actually all the warnings
   possible).

   You can actually get pretty far with just that way of using make, but
   let's get into making a Makefile so you can understand make a little
   better. To start off, create a file with just this in it:
======CFLAGS=-Wall -g======

clean:
   rm -f ex1

   Save this file as Makefile in your current directory. Make
   automatically assumes there's a file called Makefile and will just run
   it. Also, WARNING: Make sure you are only entering TAB characters, not
   mixtures of TAB and spaces.

   This Makefile is showing you some new stuff with make. First we set
   CFLAGS in the file so we never have to set it again, as well as adding
   the -g flag to get debugging. Then we have a section named clean which
   tells make how to clean up our little project.

   Make sure it's in the same directory as your ex1.c file, and then run
   these commands:
$ make clean
$ make ex1

======What You Should See======

   If that worked then you should see this:
$ make clean
rm -f ex1
$ make ex1
cc -Wall -g    ex1.c   -o ex1
ex1.c: In function 'main':
ex1.c:3: warning: implicit declaration of function 'puts'
$

   Here you can see that I'm running make clean which tells make to run
   our clean target. Go look at the Makefile again and you'll see that
   under this I indent and then I put the shell commands I want make to
   run for me. You could put as many commands as you wanted in there, so
   it's a great automation tool.

   Note

   If you fixed ex1.c to have #include <stdio.h> then your output will not
   have the warning (which should really be an error) about puts. I have
   the error here because I didn't fix it.

   Notice also that, even though we don't mention ex1 in the Makefile,
   make still knows how to build it plus use our special settings.

======How To Break It======

   That should be enough to get you started, but first let's break this
   make file in a particular way so you can see what happens. Take the
   line rm -f ex1 and dedent it (move it all the way left) so you can see
   what happens. Rerun make clean and you should get something like this:
$ make clean
======Makefile:4: *** missing separator.  Stop.======

   Always remember to indent, and if you get weird errors like this then
   double check you're consistently using tab characters since some make
   variants are very picky.

======Extra Credit======

     * Create an all: ex1 target that will build ex1 with just the command
       make.
     * Read man make to find out more information on how to run it.
     * Read man cc to find out more information on what the flags -Wall
       and -g do.
     * Research Makefiles online and see if you can improve this one even
       more.
     * Find a Makefile in another C project and try to understand what
       it's doing.


   Copyright (C) 2010 Zed. A. Shaw

   Credits