why man is called "on-line"
 

man - an interface to the on-line reference manuals
I can check man without internet connection, so what does this "on-line" mean?

Hi there,

the term is historical. Think of the era of mainframe computers and users just having a terminal on their desks. They had to connect and log in to the main computer before they could do anything at all. That's what they called "online" these days.

Though the term isn't completely apt any more, it is still being used as "sitting in front of the terminal with the system running", in contrast to an offline manual, which usually means a printed booklet or brochure - something you can read without the computer running.

[X] Doc CPU

As mentioned, it is partially historical.

But it goes back to having to check manual pages in a physical book which may have been in a different room or library (as in, a room containing reference material, not as in a specific building).

Having the reference pages "on line" and immediately searchable was a HUGE improvement for quick checks of syntax or use.

Even now, having the manuals on local storage is still better than having them on the net... and having to lookup a syntax problem to fix the network connection.

It wasn't quite as useful when you wanted to make annotation entries, put page markers/post-its with notes...

Hi there,

you clearly have a point there, reminds me of the chicken-egg-problem. ;-)
The on-line manual is fine for quickly looking up a detail and, as you say, for searching. Plus, a printed manual may quickly be out of date. But still, for half-way consolidated information, I prefer printed documentation for reference purposes. A handbook with a detailed TOC and a good keyword index, and I'm happy.

That's another benefit of printed documentation. Or try to smash a fly with an on-line manual ...

[X] Doc CPU

Almost. It doesn't only refer the the user's end of being on-line, but also to the storage volume holding the man pages. After a disk or tape unit was loaded with the proper storage media, it had to be closed, activated and to be put "on-line", meaning that a hardware connection was established with the computer and the unit was "ready" for I/O. There was usually an indicator light labeled "on-line" telling the unit's status.

The same was true for punch card readers, papertape readers and punchers, etc. Not too long ago printers had an on-line button as well.

jlinkels

Thank you guys for these answers, so much need to learn.