tasks a-s

Task/SEDOLs/AWK/sedols.awk

@@ -0,0 +1,49 @@
+function ord(a)
+{
+  return amap[a]
+}
+
+function sedol_checksum(sed)
+{
+  sw[1] = 1; sw[2] = 3; sw[3] = 1
+  sw[4] = 7; sw[5] = 3; sw[6] = 9
+  sum = 0
+  for(i=1; i <= 6; i++) {
+    c = substr(toupper(sed), i, 1)
+    if ( c ~ /[[:digit:]]/ ) {
+      sum += c*sw[i]
+    } else {
+      sum += (ord(c)-ord("A")+10)*sw[i]
+    }
+  }
+  return (10 - (sum % 10)) % 10
+}
+
+BEGIN { # prepare amap for ord
+  for(_i=0;_i<256;_i++) {
+    astr = sprintf("%c", _i)
+    amap[astr] = _i
+  }
+}
+
+/[AEIOUaeiou]/ {
+  print "'" $0 "' not a valid SEDOL code"
+  next
+}
+{
+  if ( (length($0) > 7) || (length($0) < 6) ) {
+    print "'" $0 "' is too long or too short to be valid SEDOL"
+    next
+  }
+  sedol = substr($0, 1, 6)
+  sedolcheck = sedol_checksum(sedol)
+  if ( length($0) == 7 ) {
+    if ( (sedol sedolcheck) != $0 ) {
+      print sedol sedolcheck " (original " $0 " has wrong check digit"
+    } else {
+      print sedol sedolcheck
+    }
+  } else {
+    print sedol sedolcheck
+  }
+}