To find out information about a PDF file from a Unix or Linux shell prompt, you can use the pdfinfo command. pdfinfo is a utility that is part of the poppler-utils package, which provides command-line tools for manipulating PDF files.
To use pdfinfo, you can simply specify the name of the PDF file as an argument. For example:
pdfinfo file.pdf
This will display various information about the PDF file, including the title, author, creator, producer, page size, and more.
Here is an example of the output of the pdfinfo command:
Title: My PDF File Author: John Doe Creator: Adobe Acrobat Producer: Adobe Acrobat CreationDate: D:20210628095003+00'00' ModDate: D:20210628095003+00'00' Tagged: no Form: none Pages: 10 Encrypted: no Page size: 612 x 792 pts (letter) File size: 181695 bytes Optimized: no PDF version: 1.5
You can also use the pdfinfo command with the -meta option to display the metadata of the PDF file. For example:
pdfinfo -meta file.pdf
This will display the metadata of the PDF file in an XML format.
You can use the pdfinfo command with other options to display specific information about the PDF file or to customize the output. You can refer to the pdfinfo man page or online documentation for more information.
Keep in mind that pdfinfo is just one of many tools that you can use to manipulate PDF files from the command line. There are other utilities, such as pdftotext, pdffonts, and pdftops, that can be used to extract text, display font information, and convert PDF files to other formats. You may want to refer to the poppler-utils documentation or explore other tools for working with PDF files from the command line.