From 6421f2b8265a18c68514d1005d39916efedb4871 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Paul=20H=C3=A4nsch?= <paul@plutz.net>
Date: Fri, 1 Feb 2019 06:27:57 +0100
Subject: [PATCH] previous/next link generation

---
 autoslide.sh | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100755 autoslide.sh

diff --git a/autoslide.sh b/autoslide.sh
new file mode 100755
index 0000000..a7d08bc
--- /dev/null
+++ b/autoslide.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+
+last='' curr='' next=''
+idoff=1
+
+line="$(line)"
+while :; do 
+  tag="${tag}${line%%>*}"
+
+  if [ "$line" = "${line%%>*}" ]; then
+    # $line did not contain ">" and thus was added to $tag entirely
+    if ! line="$(line)"; then
+      printf %s\\n "$tag"
+      break
+    fi
+    tag="${tag}
+"
+  else
+    # $line is shortened by segment added to $tag
+    line="${line#*>}"
+    tag="${tag}>"
+  fi
+
+  case $tag in
+    *\<slide\ *id=\"?*\"*\>*)
+      prev="$curr" curr="$next"
+      next="${tag#*<slide }"
+      next="${next#*id=\"}"
+      next="${next%\"*}"
+      printf '%s<a href="#%s">previous</a><a href="#%s">next</a><slide %s' \
+        "${tag%<slide *}" "$prev" "$next" "${tag#*<slide }"
+      tag=''
+      ;;
+    *\<slide\ *\>*)
+      prev="$curr" curr="$next"
+      next="autoslide${idoff}"
+      idoff="$((idoff + 1))"
+      printf '%s<a href="#%s">previous</a><a href="#%s">next</a><slide %s' \
+        "${tag%<slide *}" "$prev" "$next" "${tag#*<slide }"
+      tag=''
+      ;;
+    *\<*\>*)
+      printf %s "$tag"
+      tag=''
+      ;;
+    *) :
+      ;;
+  esac
+done
-- 
2.39.2