如何在 Tcl 中将 %hex 转换为字符？

Question

我需要 TCL 方面的帮助。我以以下字符串为例：

%3Cdiv%20id%3D%22video-container-direct%22%20style%3D%22position%3A%20relative%3Bpadding-bottom%3A%2056.6%25%3Bpadding-top%3A%2090px
%3Bheight%3A%200%3Boverflow%3A%20hidden%3B%22%3E%3Ciframe%20allowfullscreen%3D%22%22%20frameborder%3D%220%22%20scrolling%3D%E2%80%9Cno
%22%20src%3D%22%2F%2Fwww.vsports.pt%2Fembd%2F68680%2Fm%2F8856%2Fmaisf%2Fce1702fde64b1cf799dded7f1f3ab428%3Fautostart%3Dfalse%22%20
style%3D%22position%3A%20absolute%3Btop%3A0%3Bleft%3A%200%3Bwidth%3A%20100%25%3Bheight%3A%20100%25%3Bborder%3A0%22%3E%3C%2Fiframe
%3E%3C%2Fdiv%3E

我想替换 % 之后的所有内容并删除 % 当然。我的意思是，将%2F 转换为/，将%3D 转换为=，等等。

Answer 1

简单的方法是使用来自tcllib 的uri::urn 包（应该可以通过操作系统的包管理器安装）：

#!/usr/bin/env tclsh

package require uri::urn

set s "%3Cdiv%20id%3D%22video-container-direct%22%20style%3D%22position%3A%20relative%3Bpadding-bottom%3A%2056.6%25%3Bpadding-top%3A%2090px
%3Bheight%3A%200%3Boverflow%3A%20hidden%3B%22%3E%3Ciframe%20allowfullscreen%3D%22%22%20frameborder%3D%220%22%20scrolling%3D%E2%80%9Cno
%22%20src%3D%22%2F%2Fwww.vsports.pt%2Fembd%2F68680%2Fm%2F8856%2Fmaisf%2Fce1702fde64b1cf799dded7f1f3ab428%3Fautostart%3Dfalse%22%20
style%3D%22position%3A%20absolute%3Btop%3A0%3Bleft%3A%200%3Bwidth%3A%20100%25%3Bheight%3A%20100%25%3Bborder%3A0%22%3E%3C%2Fiframe
%3E%3C%2Fdiv%3E"

puts [uri::urn::unquote $s]

Tcl 8.7 将允许您使用regsub 来实现（URL 解码甚至是示例之一，复制如下）：

# Match one of the sequences in a URL-encoded string that needs
# fixing, converting + to space and %XX to the right character
# (e.g., %7e becomes ~)
set RE {(\+)|%([0-9A-Fa-f]{2})}

# Note that -command uses a command prefix, not a command name
set decoded [regsub -all -command $RE $string {apply {{- p h} {
    # + is a special case; handle directly
    if {$p eq "+"} {
        return " "
    }
    # convert hex to a char
    scan $h %x charNumber
    format %c $charNumber
}}}]

puts $decoded