The nitty gritty of Unix rights management
Cross-Examination
People applying for IT jobs should brace themselves for the popular interview question about the sticky bit in Unix operating systems. It certainly pays to know.
A frequently asked IT interview question concerns the "sticky bit." I do not personally ask this question when vetting a candidate, because I think anyone who knows the answers is, at best, showing good interview preparation. It does not provide any proof of professional expertise. However, many Silicon Valley companies have the question in their catalog and, as a player in the software industry's major league, you need to know the answer to unnecessary questions.
That's why I picked the topic for the Perl column this month. What is the sticky bit's purpose? Michael Kerrisk's book [2] – as always – helps when it comes to tricky Unix questions. As a hardback, this tome with more than 1,500 pages seems to be designed for bodybuilders, but it is easy to carry around anywhere as an e-book. Those who think they understand the intricacies of programming in Unix will stand back in amazement upon reading this epic book: Even gray-bearded Unix gurus will discover intriguing facts from the depths of this resource, time and time again.
For example, did you know that users on a Unix system can delete a file from a directory even if they do not have any write permissions on the file? Correct: Only write and execute permissions are required for the directory the file is located in, and the file's permissions don't matter at all. Listing 1 creates new directory test in the current directory for demonstration purposes and uses the 0333 octal value to assign permissions of -wx-wx-wx.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.
-
Bugs Found in sudo
Two critical flaws allow users to gain access to root privileges.
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
LibreOffice Tested as Possible Office 365 Alternative
Another major organization has decided to test the possibility of migrating from Microsoft's Office 365 to LibreOffice.
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.