perldoc使用

1. 查看函数的用法及作用。

语法: perldoc [options] -f BuiltinFunction
例子: 
$ perldoc -t -f rindex  # 查看函数rindex的用法、作用；
    rindex STR,SUBSTR,POSITION
    rindex STR,SUBSTR
            Works just like "index" except that it returns the position of
            the *last* occurrence of SUBSTR in STR. If POSITION is
            specified, returns the last occurrence beginning at or before
            that position.

2. 查看Module的用法及作用：

语法：perldoc [options] PageName|ModuleName|ProgramName ...
例子：
$ perldoc -t File::Basename
NAME
    File::Basename - Parse file paths into directory, filename and suffix.

SYNOPSIS
        use File::Basename;

        ($name,$path,$suffix) = fileparse($fullname,@suffixlist);
        $name = fileparse($fullname,@suffixlist);

        $basename = basename($fullname,@suffixlist);
        $dirname  = dirname($fullname);

DESCRIPTION
    These routines a...

3. 查看匹配某关键字的帮助文档：

语法：perldoc [ooptions] -q FAQRegex
例子：
$ perldoc -q "here doc" #查看包含"here doc"的帮助文档
Found in C:\Perl64\lib\pods\perlfaq4.pod
  Why don't my <<HERE documents work?
    Here documents are found in perlop. Check for these three things:

    There must be no space after the << part.
    There (probably) should be a semicolon at the end of the opening token
    You can't (easily) have any space in front of the tag.
    There needs to be at least a line separator after the end token.