For example, when I run man ioctl
the page says IOCTL(2)
at the top. What does that mean? Is there an IOCTL(1)
? And how does one navigate between these?
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Abdullah Jibaly
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Here's a list of what the man page sections refer to. http://www.december.com/unix/ref/mansec.html – SumoRunner Feb 25 '09 at 21:54
2 Answers
40
It's the man page section. From memory, section 1 is user programs, 2 is system calls, and 3 is standard C library calls, and 5 is file formats.
Wikipedia has the full explanation here.

Dana
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Paul Tomblin
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2The man page section was very useful in days of printed manuals. I still have the 4.1 BSD printed manuals in my office. (The section number also helps you know when you're calling into the kernel, versus making a library call.) – Craig S Feb 25 '09 at 21:58
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2@Craig - also useful for disambiguating, as shown in eduffy's answer. – Paul Tomblin Feb 25 '09 at 22:06
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That's the man page section number. For example
man printf
(should) Give you section 1, printf
the bash command, while
man 3 printf
gives you the C function printf
.

Bryan Oakley
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eduffy
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