[ale] pkg-config --define-variable error

[Ed L. Cashin]

2008/6/19 Marc Ferguson <marcferguson at gmail.com>:
...
> Thanks for the help.  That command did help, I only wish I knew what it
> means.

I might not be able to help much with your banshee
project, but I can tell you what the command means.  :)

export PKG_CONFIG_PATH=${PKG_CONFIG_PATH}:/usr/local/lib/pkgconfig

The shell has a collection of named variables called
environment variables.  In action, this feature looks like the
example below.  Notice how the x and y variables
aren't exported to the child process (the bash shell that
I run explicitly) unless I use the "export" keyword.

bash$ x=hello
bash$ y=world
bash$ echo $x $y
hello world
bash$ bash
ecashin at ed-cashins-computer tmp$ echo $x $y

ecashin at ed-cashins-computer tmp$ exit
exit
bash$ export x y
bash$ bash
ecashin at ed-cashins-computer tmp$ echo $x $y
hello world
ecashin at ed-cashins-computer tmp$

To append something onto the end of the current
value, you can assign something new to the variable
like this:

bash$ echo $x
hello
bash$ echo $x:there
hello:there
bash$ x=$x:there
bash$ echo $x
hello:there
bash$

The command started by appending "/usr/local/lib/pkgconfig"
to the end of the value of the environment variable named
PKG_CONFIG_PATH, and exporting that variable, so that
processes created later will have access to it.  Presumably
the next command uses that environment variable to find
non-default places to look for stuff.

pkg-config --libs taglib-sharp

This is just a normal command.  The shell looks for an
executable file named "pkg-config" in every directory in
your $PATH.  If it finds one, it runs it, passing "--libs" and
"taglib-sharp" as arguments.  Command line arguments
are just extra strings that the command can examine when
it starts running.

It looks like the pkg-config command needs to be told
that the libraries ("--libs") include "taglib-sharp".

-- 
 Ed L. Cashin <ecashin at noserose.net>