in netcat-openbsd manpage, port argument description is not good

[dinar qurbanov]

in netcat-openbsd manpage, port argument description is not good. it is this:

"port can be a specified as a numeric port number, or as a service name. Ports may be specified in a range of the form nn-mm. In general, a destination port must be specified, unless the -U option is given."

why this is not good:

really, the port argument also is used as source port: while using "nc -l 1234". this "nc -l 1234" is an example from the manpage in "CLIENT/SERVER MODEL" section, which is immediately after the port argument description. and this command works correctly. (while connecting from other computer with nc IPaddressHere 1234, it works, and in that case i think it is destination port, and thus source port for the command on first laptop. it must be source port on first comp, because a process must listen on a specific source port, they do not usually listen on all ports, as i know from my experience... unless it is something like tcpdump, and such programs run with root permission, while netcat runs with non-root permission... and it is because processes should not access to listening ports of other processes... )

the text "In general, a destination port must be specified, unless the -U option is given." is not good, because it says "must" and says "in general", and it is hard to disambiguate this. it can be understood as "in general" refers to the all cases except the "unless the -U option is given". in that way of understanding, it means that if the -U option is not given, it must be source port only. but really it is not so. so, "in general" does not refer to the all cases except the "unless the -U option is given". it just means, that destination port is more usually used in this place. but this way of understanding is also hard to accept, because the usage, the intention of the extra word "must" becomes not understood. it is extra, because it can be said shorter: "a destination port is specified", or it can be said with less of the fierce: "a destination port should be specified".

[Heinrich Schuchardt (xypron)]

This package is copied from Debian. Please, open send a bug report there. Cf. https://www.debian.org/Bugs/Reporting.