Add strip-unaffected to remove unaffected IEs

diff --git a/bin/strip-unaffected.awk b/bin/strip-unaffected.awk
new file mode 100755 (executable)
index 0000000..cdb4224
--- /dev/null
+++ b/bin/strip-unaffected.awk
@@ -0,0 +1,99 @@
+#!/bin/awk -f
+
+BEGIN {
+    # A record is an IE heading
+    RS = "-- =+\n-- IE: [A-Z][A-Za-z0-9-]+"
+
+    # A field is a line
+    FS = "\n"
+
+    ORS = ""
+    
+    # Usage explanation
+    if (ARGC != "3") {
+       print "Usage: " ARGV[0] "module.asn module-modified.asn"
+       print "Creates cr-module.asn and cr-module-modified.asn only including IEs"
+       print "that are different between module.asn and module-modified.asb"
+       exit
+    }
+
+    file = "origin"
+}
+
+BEGINFILE {
+    i = 1
+    ie_header = ""
+}
+
+{    
+    if (ie_header != "") {
+       split(ie_header, header_fields, "-- IE: ")
+        ie_name = header_fields[2]
+ 
+       module_ie[file][i]     = ie_name
+       module_ie_def[file][i] = ie_header $0
+
+       i++
+    }
+
+    ie_header = RT
+
+}
+
+ENDFILE {
+    file = "modified"
+}
+
+END {
+    stripped_origin   = "stripped_" ARGV[1]
+    stripped_modified = "stripped_" ARGV[2]
+    
+    i_origin   = 1
+    i_modified = 1
+
+    # Process IEs of the original .asn
+    while (module_ie["origin"][i_origin] != "") {
+       i_modified_search = i_modified
+
+       # Search possibly until the end in the modified .asn for the same IE name
+       while ((module_ie["modified"][i_modified_search] != "") &&
+              (module_ie["modified"][i_modified_search] != module_ie["origin"][i_origin])) { i_modified_search++ }
+
+       # If the IE of the original .asn was found in the modified .asn
+       if (module_ie["modified"][i_modified_search] == module_ie["origin"][i_origin]) {
+
+           # Any IE in the modified .asn that was skipped is new, write it to the stripped modified file
+           i = i_modified
+           while (i < i_modified_search) {
+                   print module_ie_def["modified"][i] > stripped_modified
+                   i++
+           }
+
+            # If they are different
+           if (module_ie_def["modified"][i_modified_search] != module_ie_def["origin"][i_origin]) {    
+               print module_ie_def["origin"][i_origin] > stripped_origin
+               print module_ie_def["modified"][i_modified_search] > stripped_modified
+           }
+
+           # Continue where we are
+           i_modified = i_modified_search + 1
+
+       }
+
+       # The IE of the original .asn was entirely deleted
+       else {
+           print module_ie_def["origin"][i_origin] > stripped_origin
+       }
+
+       i_origin++
+    }
+
+    while (module_ie["modified"][i_modified] != "") {
+       print module_ie_def["modified"][i_modified] > stripped_modified
+       i_modified++
+    }
+
+}
+
+
+