wget 的断点续传功能

使用-c 选项：

-c
        --continue
            Continue getting a partially-downloaded file.
            This is useful when you want to finish up a
            download started by a previous instance of
            Wget, or by another program.  For instance:

示例：

$ wget -c ftp://sunsite.doc.ic.ac.uk/ls-lR.Z