Rewrite unf(1df) in awk

Also update manual page references to it, and improve it by making it
ignore body content

1 files changed, 34 insertions, 0 deletions

diff --git a/bin/unf.awk b/bin/unf.awk
new file mode 100644
index 00000000..22a10aa8
--- /dev/null
+++ b/bin/unf.awk
@@ -0,0 +1,34 @@
+# Unfold header lines in an internet message, don't touch the body
+
+# Function to write and empty the buffer
+function wrbuf() {
+    if (length(buf))
+        print buf
+    buf = ""
+}
+
+# Flag to stop processing once we hit the first blank line
+!length {
+    wrbuf() 
+    body = 1
+}
+body {
+    print
+    next
+}
+
+# Write any buffer contents once we hit a line not starting with a space
+/^[^ \t]/ {
+    wrbuf()
+}
+
+# Append the current line to the buffer
+{
+    sub(/^[ \t]+/, " ")
+    buf = buf $0
+}
+
+# Write the buffer out again when we hit the end
+END {
+    wrbuf()
+}