Add initial source code and update README

README.md

@@ -1,2 +1,53 @@
 # perc
-PE command line resource utility: list/add/delete/extract resources in Windows PE file
+Command line PE resource utility:
+Add, replace, delete, extract or list resources in Windows PE file
+
+`perc` uses Windows API to access, enumerate or modify resources in a PE file.
+
+Pre-built 32/64 Windows binaries are available at the
+[releases page](https://github.com/avih/perc/releases).
+
+### Examples
+
+List all resources in `example.dll`:
+```sh
+perc -L example.dll
+```
+
+Add a manifest resource file `manifest.xml` as ID `1` with default
+(neutral) language to file `example.exe`:
+```sh
+perc -a manifest.xml -t MANIFEST -i 1 example.exe
+```
+
+Extract the manifest with neutral language and ID `1` from `example.exe` to
+`manifest.xml`:
+```sh
+perc -x -t MANIFEST -i 1 example.exe > manifest.xml
+```
+
+### Usage:
+```
+Usage: perc.exe  -h  |  -{D|L|R|a:|d|x} [-{t:i:l:}] [INDEX] PE
+Add, replace, delete, extract or list resources in Windows PE file.
+
+  Actions - exactly one must be specified, possibly with -n:
+    -h       Print this help and exit.
+    -n       No-write: don't modify PE, don't write list or extracted resource.
+    -D       Delete all (*) resources in PE.
+    -L       List all (*) resources in PE as  INDEX: TYPE/ID/LANG (SIZE).
+    -R       Same as -L, but TYPE is printed as raw integer, if possible.
+    -d       Delete the resource TYPE/ID/LANG in PE.
+    -x       Extract the resource TYPE/ID/LANG in PE to stdout (**).
+    -a RSRC  Add resource file RSRC (stdin if '-') as TYPE/ID/LANG to PE (**).
+  (*)  If any of TYPE, LANG, ID are given: only items with all given values.
+  (**) Raw data directly from/to PE. E.g. ICON is without header, etc.
+
+  Target - at most one TYPE, one ID, and one LANG (INDEX overrides others):
+    -t TYPE  Symbol/int/@STR resource type. E.g. -t ICON, -t 2, -t @"foo bar".
+    -i ID    Int/@STR resource ID/NAME.
+    -l LANG  Int resource language. Default for -a/-x/-d is 0 (neutral).
+    INDEX    Sets TYPE+ID+LANG of existing resource INDEX (from -L/-R output).
+
+perc v0.1  PE Resource utility  https://github.com/avih/perc
+```