Many PDFs have compressed content streams, plain text utilities only see metadata in that case. Cached, compressed text-only output is usually tiny, and can be zgrep-ed.
pdfinfo shows document metadata (title, subject, keywords and more), but it's quite uncommon for these to be useful (Adobe and LᴬTᴇX-sourced PDFs tend to have this data).
pdfinfo shows document metadata (title, subject, keywords and more), but it's quite uncommon for these to be useful (Adobe and LᴬTᴇX-sourced PDFs tend to have this data).
Both come with xpdf.