"pkg-config script could not be found" on OSX - linux

Question

I am trying to install some software on my mac; however I keep receiving the same error:
configure: error: The pkg-config script could not be found or is too old. Make sure it
is in your PATH or set the PKG_CONFIG environment variable to the full
path to pkg-config.
Alternatively, you may set the environment variables XMEDCON_GLIB_CFLAGS
and XMEDCON_GLIB_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
To get pkg-config, see <http://pkg-config.freedesktop.org/>.
See `config.log' for more details
I am not quite sure how to go about adding the pkg-config to the PATH. I have seen online (see link) that I should add the following:
Link showing how to direct PATH variable
export PATH=$PATH:/opt/local/bin # Fixed typo as mentioned in comment
which is where I have placed pkg-config. I still keep getting the error though every time I try to configure the files using ./configure. Any help would be super appreciated!

Answer 1

For Ubuntu/Debian OS,
apt-get install -y pkg-config
For Redhat/Yum OS,
yum install -y pkgconfig
For Archlinux OS,
pacman -S pkgconf

Answer 2

for me, (OSX) the problem was solved doing this:
brew install pkg-config

Answer 3

Answer to my question (after several Google searches) revealed the following:
$ curl https://pkgconfig.freedesktop.org/releases/pkg-config-0.29.tar.gz -o pkgconfig.tgz
$ tar -zxf pkgconfig.tgz && cd pkg-config-0.29
$ ./configure && make install
from the following link: Link showing above
Thanks to everyone for their comments, and sorry for my linux/OSX ignorance!
Doing this fixed my issues as mentioned above.

Answer 4

if you have this error :
configure: error: Either a previously installed pkg-config or "glib-2.0 >= 2.16" could not be found. Please set GLIB_CFLAGS and GLIB_LIBS to the correct values or pass --with-internal-glib to configure to use the bundled copy.
Instead of do this command :
$ ./configure && make install
Do that :
./configure --with-internal-glib && make install

Answer 5

Try
which pkg-config
if it is empty then fire
brew install pkg-config
OR : ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" < /dev/null 2> /dev/null

Answer 6

MacOS users
Unfortunately, pkg-config does not come with OS X by default. Here are some notes on how to compile from source. It assumes that you have Xcode installed.
Download and extract
curl -O http://pkgconfig.freedesktop.org/releases/pkg-config-0.28.tar.gz
tar xfz pkg-config-0.28.tar.gz
Configure and Install
cd pkg-config-0.28
setenv CC /usr/bin/cc (for tcsh)
export CC=/usr/bin/cc (for bash)
2a) If you have super-user powers
./configure --prefix=/usr/local CC=$CC --with-internal-glib
make
sudo make install
2b) if not
./configure --prefix=$HOME/someplace/in/my/path CC=$CC --with-internal-glib
make
make install
Source: https://opensource.ncsa.illinois.edu/confluence/display/DESDM/Installing+pkg-config+from+source+for+OSX