我正在使用 FreeBSD 9.1。
当我输入“perldoc perl”时:
PERL(1) User Contributed Perl Documentation PERL(1)
ESC[1mNAMEESC[0m
perl - The Perl 5 language interpreter
ESC[1mSYNOPSISESC[0m
ESC[1mperl ESC[22m[<C2> ESC[1m-sTtuUWXESC[22m<C2> ] [<C2> ESC[1m-hvESC[22m<C2> ]<C2> [<C2> ESC[1m-VESC[22m[:ESC[4mconfigvarESC[24m]<C2> ]
[<C2> ESC[1m-cwESC[22m<C2> ]<C2> [<C2> ESC[1m-dESC[22m[ESC[1mtESC[22m][:ESC[4mdebuggerESC[24m]
<C2> ]<C2> [<C2> ESC[1m-DESC[22m[ESC[4mnumber/listESC[24m]<C2> ]
[<C2> ESC[1m-pnaESC[22m<C2> ]<C2> [<C2> ESC[1m-FESC[4mESC[22mpatternESC[24m<C2> ]<C2> [<C2> ESC[1m-lESC[22m[ESC[4moctalESC[24m]<C2> ]<C2> [<C2> ESC[1m-0ESC[22m[ESC[4moctal/hexadecimalESC[24m]<C2> ]
[<C2> ESC[1m-IESC[4mESC[22mdirESC[24m<C2> ]<C2> [<C2> ESC[1m-mESC[22m[ESC[1m-ESC[22m]ESC[4mmoduleESC[24m<C2> ]<C2> [<C2> ESC[1m-MESC[22m[ESC[1m-ESC[22m]ESC[4m'module...'ESC[24m<C2> ]<C2> [<C2> ESC[1m-f
ESC[22m<C2> ]
[<C2> ESC[1m-C<C2> [ESC[4mnumber/listESC[24m]<C2> ESC[22m] [<C2> ESC[1m-SESC[22m<C2> ] [<C2> ESC[1m-xESC[22m[ESC[4mdirESC[24m]<C2> ]
[<C2> ESC[1m-iESC[22m[ESC[4mextensionESC[24m]<C2> ]
[<C2> [ESC[1m-eESC[22m|ESC[1m-EESC[22m]<C2> ESC[4m'command'ESC[24m<C2> ]<C2> [<C2> ESC[1m--ESC[22m<C2> ]<C2> [<C2> ESC[4mprogramfileESC[24m<C2> ]<C2> [<C2> ESC[4margumentESC[24m<C2> ]...
ESC[1mGETTING HELPESC[0m
The ESC[4mperldocESC[24m program gives you access to all the documentation that
comes with Perl. You can get more documentation, tutorials and
community support online at <http://www.perl.org/>.
If you're new to Perl, you should start by running "perldoc perlintro",
which is a general intro for beginners and provides some background to
help you navigate the rest of Perl's extensive documentation. Run
"perldoc perldoc" to learn more things you can do with ESC[4mperldocESC[24m.
For ease of access, the Perl manual has been split up into several
sections.
为什么有这么多ESC?(如果我输入 'man perl' 没有这个问题。)