Reading File Metadata with extract and libextractor
Listing 8. jpegextractor.c adds the MIME type to the list after parsing the file header.
if ( (data != 0xFF) || (data != 0xD8) ) return prev; /* not a JPEG */ addKeyword(&prev, strdup("image/jpeg"), EXTRACTOR_MIMETYPE); /* ... more parsing code here ... */ return prev;
libextractor is a simple extensible C library for obtaining metadata from documents. Its plugin architecture and broad support for formats set it apart from format-specific tools. The design is limited by the fact that libextractor cannot be used to update metadata, which more specialized tools typically support.
Resources for this article: /article/8207.
Christian Grothoff graduated from the University of Wuppertal in 2000 with a degree in mathematics. He currently is a PhD student in computer science at Purdue University, studying static program analysis and secure peer-to-peer networking. A Linux user since 1995, he has contributed to various free software projects and now is the maintainer of GNUnet and a member of the core team for libextractor. His home page can be found at grothoff.org/christian.
One Click, Universal Protection: Implementing Centralized Security Policies on Linux Systems
Join editor Bill Childers and Bit9's Paul Riegle on April 27 at 12pm Central to learn how to keep your Linux systems secure.
Free to Linux Journal readers.Register Now!
|Security Hardening with Ansible||Aug 18, 2014|
|Monitoring Android Traffic with Wireshark||Aug 14, 2014|
|IndieBox: for Gamers Who Miss Boxes!||Aug 13, 2014|
|Non-Linux FOSS: a Virtualized Cisco Infrastructure?||Aug 11, 2014|
|Linux Security Threats on the Rise||Aug 08, 2014|
|Android Candy: Oyster—Netflix for Books!||Aug 07, 2014|
- NSA: Linux Journal is an "extremist forum" and its readers get flagged for extra surveillance
- Security Hardening with Ansible
- Returning Values from Bash Functions
- Examining Load Average
- Why Python?
- Writing a Simple USB Driver
- Reducing Boot Time in Embedded Linux Systems
- RSS Feeds
- Tech Tip: Really Simple HTTP Server with Python
- Hack and / - Linux Troubleshooting, Part I: High Load