pdfgrep is a GNU/Emacs module providing grep comparable facilities
but for PDF files. Its usage is similar to the grep function: using
the next-error function gets you to the next matching page…
The pdfgrep program must be installed on your system.
If the pdf-tools module is installed and enabled, when a matching page is displayed, the matching regions are highlighted.
(require 'pdfgrep)
(pdfgrep-mode)