Add simple build and use instructions

README.md

@@ -1,10 +1,13 @@
-C++11 ELF/DWARF parser
-----------------------
-
 Libelfin is a from-scratch C++11 library for reading ELF binaries and
 DWARFv4 debug information.
 
-### Features
+Quick start
+-----------
+
+`make`, and optionally `make install`.  You'll need GCC 4.7 or later.
+
+Features
+--------
 
 * Native C++11 code and interface, designed from scratch to interact
   well with C++11 features, from range-based for loops to move
@@ -29,16 +32,31 @@ DWARFv4 debug information.
 
 * Large collection of type-safe DIE attribute fetchers.
 
-### Non-features
+Non-features
+------------
 
 Libelfin implements a *syntactic* layer for DWARF and ELF, but not a
 *semantic* layer.  Interpreting the information stored in DWARF DIE
 trees still requires a great deal of understanding of DWARF, but
 libelfin will make sense of the bytes for you.
 
-### Status
+Using libelfin
+--------------
+
+To build against `libdwarf++`, use, for example
+
+    g++ -std=c++11 a.cc $(pkg-config --cflags --libs libdwarf++)
+
+To use a local build of libelfin, set `PKG_CONFIG_PATH`.  For example,
+
+    export PKG_CONFIG_PATH=$PWD/elf:$PWD/dwarf
+
+There are various example programs in `examples/`.
+
+Status
+------
 
 Libelfin is a good start.  It's not production-ready and there are
-many parts of the DWARF specification is does not yet implement, but
+many parts of the DWARF specification it does not yet implement, but
 it's complete enough to be useful for many things and is a good deal
 more pleasant to use than every other debug info library I've tried.