Add a script to tool/ that will extract the sqlite3.h header file from an

sqlite3.c amalgamation.

FossilOrigin-Name: 38d2e510cdedf38153466b161c0842b1604aef7b5589c51f628ae7cbb6a8722a

tool/extract-sqlite3h.tcl

@@ -0,0 +1,21 @@
+#!/usr/bin/tclsh
+#
+# Given an sqlite3.c source file identified by the command-line
+# argument, extract the "sqlite3.h" header file that is embedded inside
+# the sqlite3.c source file and write it to standard output.
+#
+if {[llength $argv]!=1} {
+  puts stderr "Usage: $argv0 sqlite3.c >sqlite3.h"
+  exit 1
+}
+set in [open [lindex $argv 0] rb]
+while {![eof $in]} {
+  set line [gets $in]
+  if {[string match {* Begin file sqlite3.h *} $line]} break
+}
+while {![eof $in]} {
+  set line [gets $in]
+  if {[string match {* End of sqlite3.h *} $line]} break
+  puts $line
+}
+close $in