added binary.txt, notes for xxd(1) & od(1)

1 files changed, 52 insertions, 0 deletions

diff --git a/binary.txt b/binary.txt
new file mode 100644
index 0000000..908fff7
--- /dev/null
+++ b/binary.txt
@@ -0,0 +1,52 @@
+.:: Binary ::.
+--------------------------------------------------------------------------------
+
+# od(1)
+========
+  args:
+    -An         don't print addr info
+    -tx4        print hex in 4 byte chunks
+    -ta         print as named character
+    -tc         printable chars or backslash escape
+    -w4         print 4 bytes per line
+
+  echo -n AAAABBBB | od -An -w4 -tx4
+    >> 41414141
+    >> 42424242
+
+  echo -n "\x7fELF\n" | od -tx1 -ta -tc
+    >> 0000000  7f  45  4c  46  0a
+    >>         del   E   L   F  nl
+    >>         177   E   L   F  \n
+
+# xxd(1)
+=========
+  args:
+    -p          dump continuous hexdump
+    -r          convert hexdump into binary ('revert')
+    -e          dump as little endian mode
+    -i          output as C array
+
+  ## from ascii to hex stream
+  echo -n 'aabb' | xxd -p
+    >> 61616262
+
+  ## from hex to binary stream
+  echo -n '61616262' | xxd -p -r
+    >> aabb
+
+  ## ascii to binary
+  echo -n "\x7fELF" | xxd -p | xxd -r -p | file -p -
+    >> ELF
+
+  ## ascii to C array (hex encoded)
+  xxd -i <(echo -n '\x7fELF')
+    >> unsigned char _proc_self_fd_11[] = {
+    >>   0x7f, 0x45, 0x4c, 0x46
+    >> };
+    >> unsigned int _proc_self_fd_11_len = 4;
+
+
+--------------------------------------------------------------------------------
+vim:sts=2:et:tw=80:cc=80:fo+=t
+