You could switch to luatex then append from Lua. Failing that, more efficient than repeatedly reading and copying in tex way would be to not append but write a new file each time file-1.x file-2.x ... then concat them in your operating system concat in a nix shell, or copy*.x > realfile.txt in windows (I think)
David On Sun, 21 Jul 2024 at 14:12, Philip Taylor (RHBNC) via XeTeX <xetex@tug.org> wrote: > I am 99.999% certain that the answer is "no", but I still *hope* that the > answer might be "yes" — is it possible to use \immediate \openout and > \immediate \write in such a way as to *append* to an existing file rather > than overwriting it ? If not, is there a more efficient way of achieving > this than opening the existing file for reading, copying it to a temporary > file, closing both, re-opening the temporary file for reading, re-opening > the existing file for writing, copying the former to the latter, and then > and only then performing the desired \writes ? > -- > *Philip Taylor* > > This email, its contents and any attachments are intended solely for the > addressee and may contain confidential information. In certain > circumstances, it may also be subject to legal privilege. Any unauthorised > use, disclosure, or copying is not permitted. If you have received this > email in error, please notify us and immediately and permanently delete it. > Any views or opinions expressed in personal emails are solely those of the > author and do not necessarily represent those of Royal Holloway, University > of London. It is your responsibility to ensure that this email and any > attachments are virus free. > >
