feat: Basic attachment support

src/awk/attachls.awk

@@ -0,0 +1,46 @@
+# Decide if we need to read more to get all properties
+# 
+# @input str: strin read so far
+# @return: 1 if we need more data, 0 otherwise
+function cont_reading(str) {
+  return index(str, ":") ? 0 : 1
+}
+
+# Get information about attachment
+#
+# @input i: Attachment index
+# @input str: Attachment string (at least up to content separator `:`)
+# @return: informative string
+function att_info(i, str,    cnt, k, info) {
+  str = substr(str, 1, index(str, ":") - 1)
+  cnt = split(str, props)
+  info = "Attachment "i":"
+  if (cnt > 1) {
+    for (k=2; k<=cnt; k++) {
+      pname = substr(props[k], 1, index(props[k], "=") - 1)
+      pvalu = substr(props[k], index(props[k], "=") + 1)
+      if (pname == "ENCODING" && pvalu = "BASE64")
+        enc = "base64"
+      if (pname == "FILENAME")
+        fin = pvalu
+      if (pname == "VALUE")
+        val = pvalu
+      if (pname == "FMTTYPE")
+        type = pvalu
+    }
+    if (fin)
+      info = info " \"" fin "\""
+    if (type)
+      info = info " " type
+    if (enc)
+      info = info " (inline)"
+  }
+  print i, fin, type, enc, info
+}
+
+BEGIN            { FS="[:;]"; OFS="\t" }
+/^END:VEVENT$/   { ins = 0; exit }
+l && !r          { att_info(i, l); l = "" }
+/^ / && r        { l = l substr($0, 2); r = cont_reading($0) }
+/^ATTACH/ && ins { i++; l = $0; r = cont_reading($0) }
+/^BEGIN:VEVENT$/ { ins = 1 }