man7.org
At a glance
- Category
- Development
- Language
- English
- Paid-content signal
- No paid content foundObserved
- Registered
- 2005
- Hosting
- M-net Telekommunikations GmbHInferred
- HTTPS certificate trusted
- PassedObserved
- Last updated
Related questions
More questions →What training courses does man7.org offer?
man7.org lists training courses as one of its main offerings, alongside The Linux Programming Interface, conference presentations, the man-pages project, and the online manual pages. The site is Michael Kerrisk's personal and project hub, so the training is tied to his own teaching rather than to a large catalog from multiple instructors. The available page evidence confirms that training courses exist as a section of the site, but it does not include course names, formats, schedules, or registration details. Those specifics have to be checked on the site itself.
What the site confirms
The man7.org homepage presents these sections:
- Training courses
- The Linux Programming Interface
- Conference presentations
- The man-pages project
- Online manual pages
- Articles
- Blog
- About
- Contact and Impressum
Because "Training courses" appears as a top-level item, it is a distinct part of the site rather than a subsection buried under another topic. The instructor is Michael Kerrisk, the author of The Linux Programming Interface and the longtime maintainer of the Linux man-pages project.
What is not confirmed by the available evidence
The provided page evidence does not state:
- Which specific courses are offered
- Whether courses are online, in-person, or self-paced
- Course duration, price, or prerequisites
- Upcoming schedules or registration steps
- Whether registration happens on man7.org or through a third party
Any of these details should be treated as unknown until verified on the site.
How to find the actual course details
- Go to man7.org.
- Open the Training courses section from the main navigation or homepage list.
- Look for course titles, descriptions, and any stated format (online, in-person, or self-paced).
- Check for a schedule, registration link, or contact method.
- If the page points to an external registration platform, follow that link for dates and payment terms.
Expected result: you should end up on a page that either lists specific courses with logistics or directs you to a contact/registration channel. If the Training courses page only describes the courses without dates, use the Contact and Impressum section to ask about availability.
Who this is for
The training is most relevant if you want instruction connected to the material behind The Linux Programming Interface and the Linux man-pages project — that is, Linux and UNIX system programming topics. If you are looking for a broad multi-instructor course marketplace, man7.org is not that; it is a single-author resource site.
Practical checkpoints before signing up
- Confirm the course format, since the site evidence does not specify online vs. in-person vs. self-paced.
- Confirm the language of instruction.
- Confirm whether any materials or prerequisites are included.
- Confirm the cancellation or refund terms if payment is involved.
- Confirm the time zone if the course is live and remote.
These are the details most likely to change and most likely to affect your decision, so verify them directly on the Training courses page or via the contact information listed there.
What Is *The Linux Programming Interface* by Michael Kerrisk?
The Linux Programming Interface (often shortened to TLPI) is a book by Michael Kerrisk that serves as a comprehensive guide to Linux and UNIX system programming. It is closely tied to man7.org, Kerrisk's personal site, which hosts his training courses, conference presentations, the man-pages project, and online manual pages. If you are looking for a single reference on how to write system-level programs on Linux — using system calls, the C library, and kernel interfaces — TLPI is one of the standard works in that space, and man7.org is the hub where its author's related material lives.
What the book covers
TLPI is organized as a detailed tour of the Linux/UNIX programming interface. Its scope includes:
- Files and I/O — file descriptors,
open/read/write, file status flags, and the/procfilesystem. - Processes — process creation with
fork, program execution withexec, process termination, and process groups and sessions. - Memory — memory allocation on the heap and stack, and virtual memory concepts.
- Signals — signal handling, blocking, and the signal-driven I/O model.
- Threads — POSIX threads, synchronization primitives, and thread safety.
- Interprocess communication — pipes, FIFOs, message queues, semaphores, shared memory, and sockets.
- File systems and directories — directory operations, file attributes, and links.
- Time, users, and groups — clocks, timers, and the user/group model.
The book is written for programmers who already know C and want to understand how the operating system exposes its services, rather than for application-level developers working only with high-level frameworks.
How it relates to man7.org and the man-pages project
man7.org is Michael Kerrisk's site, and its homepage lists several distinct resources:
- Training courses — courses Kerrisk teaches on Linux system programming.
- The Linux Programming Interface — the book itself.
- Conference presentations — talks he has given.
- The man-pages project — the project that maintains the Linux manual pages (section 2, 3, and related pages).
- Online manual pages — browsable versions of the man pages.
- Articles and a Blog.
The connection matters because the man-pages project is the upstream source for much of the documentation that TLPI explains in depth. When you read a man page for a system call such as fork(2) or epoll(7), you are often reading text maintained through that project. TLPI expands on those pages with background, examples, and rationale that a man page does not have room for.
Who it is for
TLPI is aimed at:
- Systems programmers and embedded developers working in C on Linux or UNIX.
- Students in operating systems or systems programming courses.
- Developers who need to understand what happens below a language runtime or framework.
It assumes familiarity with C and basic UNIX command-line usage. It is a reference and a teaching text, not an introductory programming book.
Related resources on man7.org
If you want to go beyond the book, man7.org provides:
- Online manual pages — a browsable copy of the Linux man pages, useful for quick lookups of specific functions and system calls.
- The man-pages project — information about the project that maintains those pages.
- Training courses — instructor-led material on the same subject area.
- Conference presentations and articles — additional explanations and talks by the author.
The site's homepage presents these as separate sections, so you can move between the book, the manual pages, and the training material depending on whether you need a deep explanation, a quick reference, or structured instruction.
What Manual Pages Are Available on man7.org and How to Use Them
man7.org hosts an online mirror of Linux manual pages, maintained by Michael Kerrisk, the longtime maintainer of the Linux man-pages project. You can browse or search pages covering system calls, library functions, commands, file formats, and more — without installing anything locally. It's most useful when you're on a machine without man installed, reading from a phone, or want to link someone directly to a specific page.
What kinds of manual pages are available
The online collection follows the standard Linux manual section structure:
| Section | Content | Example |
|---|---|---|
| 1 | User commands | ls, grep |
| 2 | System calls | open, fork |
| 3 | Library functions | printf, malloc |
| 4 | Special files / devices | null, tty |
| 5 | File formats and conventions | proc, passwd |
| 6 | Games | — |
| 7 | Miscellaneous / overviews | signal, socket |
| 8 | System administration commands | mount, iptables |
Section 3 also contains the POSIX and C library pages (often labeled 3p for POSIX). The site covers Linux manual pages, and because many of these pages document interfaces shared with Unix systems, they're frequently useful for Unix-family work too — but the authoritative source for a specific Unix variant is that vendor's own documentation.
How to browse and search
Browse by section: The site lists pages grouped by section number, so you can scan section 2 for system calls or section 5 for file formats.
Search: Use the site's search to find a page by name. If a name exists in multiple sections (for example open in section 2 and open in section 3), you'll get the matching pages and can pick the right one.
Direct URLs: Each page has a stable URL, which makes it convenient to share a link to a specific function or command in documentation, issues, or chat.
Relationship to the man-pages project
The man-pages project is the upstream source for most of the section 2, 3, 4, 5, 7, and 8 pages on Linux. man7.org is Kerrisk's site and serves as the online home for that project alongside the rendered pages. That means the content you read online reflects the same pages that ship with Linux distributions, though a given distribution may carry a slightly older or patched version.
Practical notes
- Version differences matter. A page online may be newer than what's installed on your system. If behavior doesn't match, check
manlocally or the page's version notes. - Not a tutorial. Manual pages document interfaces precisely; they assume you know the surrounding concepts. For learning, pair them with a guide or book.
- The site also hosts related material from Kerrisk, including information about The Linux Programming Interface and training courses, but the manual pages are the core reference content.
If you need a quick, linkable, install-free reference for a Linux interface, man7.org is a reasonable first stop. If you need the exact behavior of the software on your own machine, use the local man command instead.
What Is man7.org?
man7.org is the personal and project site of Michael Kerrisk, best known as the longtime maintainer of the Linux man-pages project. It hosts one of the most widely used collections of online Linux/Unix manual pages, along with information about his book The Linux Programming Interface, training courses, conference presentations, articles, and a blog. It is a reference and learning resource, not a commercial software product.
What you'll find on the site
The homepage lists the main sections:
- Online manual pages — browsable Linux/Unix man pages, the most common reason people land on the site.
- The Linux Programming Interface — the book by Michael Kerrisk covering Linux and UNIX system programming.
- The man-pages project — the upstream project that maintains the Linux man pages.
- Training courses — courses taught by Kerrisk.
- Conference presentations — talks and slides.
- Articles and a Blog.
- About and Contact and Impressum pages.
When to use it
Use man7.org when you need to look up the exact behavior, options, or return values of a Linux system call, C library function, or command, or when you want authoritative documentation rather than a summary. It's also useful if you're studying Linux system programming and want material tied to The Linux Programming Interface.
What it is not
It is not a general Linux tutorial site or a distribution-specific knowledge base. The content centers on manual pages and Kerrisk's own projects and writing. If you need distro-specific configuration guides, vendor documentation is a better fit.
Practical note
The site is in English and is organized around reference material, so expect terse, precise pages rather than step-by-step walkthroughs. For a quick lookup, the online manual pages section is the fastest entry point; for deeper study, the book and articles sections are the place to start.
Website Overview
Identifiable technologies and additional version or configuration signals make the service easier to fingerprint, which may help targeted scanners narrow their checks. An established domain and managed infrastructure suggest continuity of operations and may support dependable delivery, although neither guarantees service quality.
Domain and Registration
Registered in 2005, this domain has about 20 years of history. That suggests continuity, although ownership and purpose may have changed. Transfer-protection status is present, helping reduce the risk of unauthorized domain transfers. The registrar is Gandi SAS, a widely used domain service provider. The domain uses the common .org extension, which is not an independent safety signal.
DNS and Email
Nameservers are provided by gandi.net, indicating managed DNS hosting. MX records point to the Google Workspace email service. No CNAME was found; the observed records resolve directly to addresses. SPF and DMARC are configured. DKIM status is unknown. TXT records include verification markers for Google. Such markers may also remain after a service stops being used.
TLS and Certificates
The certificate uses an RSA 2048-bit public key, offering broad client compatibility. The server supplied a complete certificate chain. No organization name is present in the certificate; the available fields are consistent with domain validation. The certificate was issued by Let's Encrypt, commonly associated with automated certificate services. The certificate's total validity is about 89 days, consistent with a short renewal cycle.
HTTP and Browser Security
The Server header exposes the software version: Apache/2.4.58 (Ubuntu). This makes version-targeted checks easier, but is not proof of an exploitable vulnerability. The checked browser-security headers were not detected, leaving fewer explicit browser-side safeguards. No X-Powered-By header was found, reducing one common source of backend fingerprinting information. No obvious internal addresses or debug information were found in the headers. No explicit CDN or WAF marker was found in the response headers.
Technology Stack Analysis
The public page identifies Apache 2.4.58, with exact versions exposed for 1 technologies. These details can narrow vulnerability checks, although exposure alone is not a vulnerability.
Search and Social Sharing
No homepage meta description was detected, leaving snippet selection more dependent on page text. No homepage canonical URL was detected. If duplicate URLs exist, consolidation may be less explicit. No Open Graph metadata was detected, so social previews may depend on platform inference. The title has 26 characters, within a common display range. The observed directives allow indexing and link following.
Hosting and Email
Registration details
| Registrar | Gandi SAS |
|---|---|
| Registered | 2005-12-15 |
| Expires | 2029-12-15 |
| Domain status | client transfer prohibited |
| Nameservers | ns-102-a.gandi.net、ns-203-b.gandi.net、ns-24-c.gandi.net |
| DNSSEC | unsigned |
DNS records
| Type | Name | Value | TTL | Priority |
|---|---|---|---|---|
| A | man7.org | 45.84.74.9 | 900 | — |
| MX | man7.org | aspmx.l.google.com | 1800 | 1 |
| MX | man7.org | alt1.aspmx.l.google.com | 1800 | 5 |
| MX | man7.org | alt2.aspmx.l.google.com | 1800 | 5 |
| MX | man7.org | ALT3.aspmx.l.google.com | 1800 | 10 |
| MX | man7.org | ALT4.aspmx.l.google.com | 1800 | 10 |
| NS | man7.org | ns-102-a.gandi.net | 10800 | — |
| NS | man7.org | ns-203-b.gandi.net | 10800 | — |
| NS | man7.org | ns-24-c.gandi.net | 10800 | — |
| TXT | man7.org | google-site-verification=6yqdzWtjBD9BVkrXEriCj0oCiw6p0kAOdZs09mcRoeg | 10800 | — |
| TXT | man7.org | v=spf1 include:_spf.google.com ~all | 10800 | — |
| DMARC | _dmarc.man7.org | v=DMARC1; p=none | 10800 | — |
TLS and certificates
HTTP response headers
| Header | Value |
|---|---|
| content-type | text/html |
| server | Apache/2.4.58 (Ubuntu) |
Identified technologies
Pages, Search and Sharing
| Meta description | Not detected |
|---|---|
| Canonical URL | Not detected |
| Language | English (default) |
| Twitter Card | Not detected |
Unknown
robots.txt (opens in a new tab)
4 rulesAll bots 0 allowed · 4 disallowed
- Disallow
/mtk/photos/ - Disallow
/mtk/contact.html - Disallow
*@@*.html - Disallow
*.license.html
No matching rules.
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