The nitty gritty of Unix rights management
Bonus Points
Job candidates receive bonus points if they can explain when Unix displays a directory's sticky bit with t and when with T. The hack with the sticky bit covers the bit that actually displays general execution rights to the directory with the final t in rwt. It is no longer possible to say whether rw- or rwx was configured before the sticky bit was turned on. Unix therefore displays rwt if rwx was present and displays rwT if execute permissions are missing – that is, if rw- existed previously.
Those who also know that not just directories, but also files, can take a sticky bit – which, however, controls something completely different – will demonstrate that they have taken their preparation seriously and have studied Kerrisk's book. These candidates are sure to score 100 points and make it to the next round!
Infos
- Listings for this article: ftp://ftp.linux-magazine.com/pub/listings/magazine/177
- Kerrisk, Michael. The Linux Programming Interface: A Linux and UNIX System Programming Handbook. No Starch Press, 2010.
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