> [B] OR Use XIncludes ?and in such case, the included file (e.g. a > refentry) must really start with the proper <!DOCTYPE> (e.g. <!DOCTYPE > refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" > "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd";>)
> > Therefore, now that we know that you use XIncludes, we really recommend > that you write and run this Perl script in order to add the proper > <!DOCTYPE> to your numerous XML files. Feeling somewhat daring, I found that the following bash commands did the trick: (1) MAKE .. A .. BACKUP .. OF .. THE .. DIRECTORY .. AND .. .. (2) doctype='<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd";>' for file in *.xml; do sed -i "2i$doctype" "$file"; done This technique, while not =generally= applicable, was sufficient in this case. It uses the "-i" (in-place) option of the "sed" (stream editor) command that standard-equipment in Unix/Linux environments. The command inserts the specified DOCTYPE declaration as the second line of all files in the directory. (I had already verified that none of them contained a "doctype.") In this way, hundreds of files were identically processed in a couple of seconds. Again: this is "for one's edification and amusement only." "Do not try this at home." But in my specific case it did work well and let me avoid writing a Perl script altogether.
