How to use the command pdfinfo (with examples)
The pdfinfo command is a portable document format (PDF) file information viewer. It allows users to retrieve various details about a PDF file, such as its title, author, subject, number of pages, and more.
Use case 1: Print PDF file information
Code:
pdfinfo path/to/file.pdf
Motivation: Printing PDF file information can be useful in various scenarios. For example, if you need to quickly check the number of pages in a PDF document or retrieve metadata about a PDF file, you can use the pdfinfo command to accomplish this task.
Explanation:
- pdfinfo: This is the command used to invoke the pdfinfo tool.
- path/to/file.pdf: This is the path to the PDF file for which you want to retrieve information.
Example output:
Title: Document Title
Author: John Doe
Subject: Sample PDF Document
Keywords: Test, Example, PDF
Creator: Microsoft Word
Producer: Adobe PDF Library 15.0
CreationDate: 2022-01-01T12:00:00Z
ModDate: 2022-01-01T14:30:00Z
Tagged: yes
Pages: 10
Encrypted: no
Page size: 612 x 792 pts (letter)
File size: 12345 bytes
Optimized: no
PDF version: 1.7
Use case 2: Specify user password for PDF file to bypass security restrictions
Code:
pdfinfo -upw password path/to/file.pdf
Motivation: In some cases, PDF files may be password-protected to restrict access to their content. If you have the user password for a PDF file, you can use the pdfinfo command with the -upw option to provide the password and bypass the security restrictions.
Explanation:
- -upw password: This option is used to specify the user password for the PDF file. Replace “password” with the actual password for the file.
- path/to/file.pdf: This is the path to the password-protected PDF file.
Example output:
Title: Encrypted Document
Author: Confidential
Subject: Sensitive Information
Keywords: Confidential, Secure, PDF
Creator: Unknown
Producer: Unknown
CreationDate: 2022-01-01T09:00:00Z
ModDate: 2022-01-01T09:30:00Z
Tagged: yes
Pages: 5
Encrypted: yes (print:yes copy:no change:no addNotes:no)
Page size: 612 x 792 pts (letter)
File size: 54321 bytes
Optimized: no
PDF version: 1.4
Use case 3: Specify owner password for PDF file to bypass security restrictions
Code:
pdfinfo -opw password path/to/file.pdf
Motivation: PDF files can have specific security settings that require an owner password to override certain restrictions. If you possess the owner password for a PDF file, you can use the pdfinfo command with the -opw option to provide the password and bypass these security restrictions.
Explanation:
- -opw password: This option is used to specify the owner password for the PDF file. Replace “password” with the actual password for the file.
- path/to/file.pdf: This is the path to the PDF file with owner password protection.
Example output:
Title: Restricted Document
Author: Confidential
Subject: Internal Use Only
Keywords: Internal, Restricted, PDF
Creator: Unknown
Producer: Unknown
CreationDate: 2022-01-01T10:00:00Z
ModDate: 2022-01-01T10:30:00Z
Tagged: yes
Pages: 8
Encrypted: yes (print:no copy:no change:no addNotes:no)
Page size: 612 x 792 pts (letter)
File size: 23456 bytes
Optimized: no
PDF version: 1.5
Conclusion:
The pdfinfo command is a versatile tool for retrieving information about PDF files. Whether you need basic details like the number of pages or more specific metadata such as the title, author, or encryption status, pdfinfo provides a simple and efficient way to access this information. Additionally, it can handle password-protected PDF files, allowing you to bypass security restrictions with either the user password or the owner password.
