README: Add section on how to use libnet with pkg-config

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/README.md b/README.md
index 48e8200..09f35af 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,34 @@ UNIX and GNU/Linux systems, see `chmcmd`, which is available in the
     sudo apt install fp-utils-3.0.4
 
 
+Using -lnet
+-----------
+
+Libnet is installed as a library and a set of include files.  The main
+include file to use in your program is:
+
+    #include <libnet.h>
+
+To get the correct search paths to both the header and library files,
+use the standard `pkg-config` tool:
+
+    $ pkg-config --libs --static --cflags libnet
+    -I/usr/local/include -L/usr/local/lib -lnet
+
+The prefix path `/usr/local/` shown here is only the default.  Use the
+`configure` script to select a different prefix when installing libnet.
+
+For GNU autotools based projects, use the following in `configure.ac`:
+
+    # Check for required libraries
+    PKG_CHECK_MODULES([libnet], [libnet >= 1.2])
+
+and in your `Makefile.am`:
+
+    proggy_CFLAGS = $(libnet_CFLAGS)
+    proggy_LDADD  = $(libnet_LIBS)
+
+
 Origin & References
 -------------------