--- /dev/null
+#!/bin/sh
+
+hxtoh()
+{
+ flag=1
+ while read -r str; do
+ case $str in
+ HXCOMM*)
+ ;;
+ STEXI*|ETEXI*|SQMP*|EQMP*) flag=$(($flag^1))
+ ;;
+ *)
+ test $flag -eq 1 && printf "%s\n" "$str"
+ ;;
+ esac
+ done
+}
+
+hxtotexi()
+{
+ flag=0
+ line=1
+ while read -r str; do
+ case "$str" in
+ HXCOMM*)
+ ;;
+ STEXI*)
+ if test $flag -eq 1 ; then
+ echo "line $line: syntax error: expected ETEXI, found $str" >&2
+ exit 1
+ fi
+ flag=1
+ ;;
+ ETEXI*)
+ if test $flag -ne 1 ; then
+ echo "line $line: syntax error: expected STEXI, found $str" >&2
+ exit 1
+ fi
+ flag=0
+ ;;
+ SQMP*|EQMP*)
+ if test $flag -eq 1 ; then
+ echo "line $line: syntax error: expected ETEXI, found $str" >&2
+ exit 1
+ fi
+ ;;
+ DEFHEADING*)
+ echo "$(expr "$str" : "DEFHEADING(\(.*\))")"
+ ;;
+ ARCHHEADING*)
+ echo "$(expr "$str" : "ARCHHEADING(\(.*\),.*)")"
+ ;;
+ *)
+ test $flag -eq 1 && echo "$str"
+ ;;
+ esac
+ line=$((line+1))
+ done
+}
+
+hxtoqmp()
+{
+ IFS=
+ flag=0
+ line=1
+ while read -r str; do
+ case "$str" in
+ HXCOMM*)
+ ;;
+ SQMP*)
+ if test $flag -eq 1 ; then
+ echo "line $line: syntax error: expected EQMP, found $str" >&2
+ exit 1
+ fi
+ flag=1
+ ;;
+ EQMP*)
+ if test $flag -ne 1 ; then
+ echo "line $line: syntax error: expected SQMP, found $str" >&2
+ exit 1
+ fi
+ flag=0
+ ;;
+ STEXI*|ETEXI*)
+ if test $flag -eq 1 ; then
+ echo "line $line: syntax error: expected EQMP, found $str" >&2
+ exit 1
+ fi
+ ;;
+ *)
+ test $flag -eq 1 && echo "$str"
+ ;;
+ esac
+ line=$((line+1))
+ done
+}
+
+case "$1" in
+"-h") hxtoh ;;
+"-t") hxtotexi ;;
+"-q") hxtoqmp ;;
+*) exit 1 ;;
+esac
+
+exit 0