bash - 转义参数中的冒号、等于、& 符号

Question

下面是我的代码，其行为非常奇怪，我不确定我是否理解原因，但我认为它在某种程度上与路径扩展有关:

编辑:这是第二个 list 中提到的asxgrab脚本:

#!/usr/bin/env bash

let "i=0"

GET "$1" | grep 'href="mms://' | while read line
do
    echo "$line"
    address=`echo $line | grep -Eow '"[^"]+"'`
    address_length=$((${#address}-2))
    address=${address:1:address_length}
    echo "Grabbing '$address', attempt $i, $address_length"
    mplayer "'$address' -dumpstream -dumpfile '$2.wmv' -vf scale\=320\:240" > /dev/null
    if [ ! $? ]; then
        break 1
    fi
    let "i++"
done

我尝试了数十种不同的转义、引用等方法，我想我已经耗尽了我的创造力......请帮忙!

假设使用这些参数调用脚本:

./asxgrab 'http://switch3.castup.net/cunet/gm.asp?ai=16&ip=79.180.37.230&course=c20478/2012b&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&ar=c20478_12b_784_01_1&ticket=58353E7A69BF1B9XO655E9E683016C5255C08DD37211ECF495F72A64E5278AA434CSP3C10C028D604AAD6C39FE7D71386D230983BBAF58A2511D14222F95090AE2C4C55CB696B82919A5A8EB44EAF8954DEDB5' 'java.0'

收到的响应如下所示:

<asx version="3.0">
    <!-- GMX -->
    <param name="encoding" value="utf-8" />
    <title>CastUP: c20478_12b_784_01_1</title>
    <MOREINFO HREF = "" />

    <entry>
    <PARAM NAME="EntryType" VALUE="Content" />

    <param name="encoding" value="utf-8" />
    <PARAM NAME="CastUP_AssociatedURL" VALUE="" />
    <PARAM NAME="CastUP_Content_Config" VALUE="" />
    <PARAM NAME="CastUP_Content_ClipMediaID" VALUE="9067325" />
    <author>openu</author>
        <title>CastUP: c20478_12b_784_01_1</title>
<ref href="mms://s3fwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=FE81687B-33CD-4441-A8F6-1DEC9923332C&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183" />
<ref href="...." />

    </entry>

当我这样做时:

mplayer "mms://s3fwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=C6527A33-587F-4148-A3D2-E7EDED51316B&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183" -dumpstream -dumpfile java0.wmv -vf scale=320:240

从终端，它可以工作，但它不能从脚本工作。相反，它会尝试修剪 $line 或类似的内容。我什至不明白发生了什么，但输出绝对没有任何后果......

这是我大学的网站，这是一个关于 Java 的讲座，虽然很有趣:)

编辑:

<ref href="mms://s0dwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=111A3770-29DC-40EC-85EC-93453E2819D7&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183" />
Grabbing 'mms://s0dwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=111A3770-29DC-40EC-85EC-93453E2819D7&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183', attempt 0, 268
Can't open joystick device /dev/input/js0: No such file or directory
Can't init input joystick
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
No stream found to handle url 'mms://s0dwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=111A3770-29DC-40EC-85EC-93453E2819D7&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183' -dumpstream -dumpfile 'java.0.wmv' -vf scale=320:240
d324d1043027b0720c295b93e4abb183" />
Grabbing '', attempt 1, -2
Can't open joystick device /dev/input/js0: No such file or directory
Can't init input joystick
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
File not found: ''' -dumpstream -dumpfile 'java.0.wmv' -vf scale=320:240'
Failed to open '' -dumpstream -dumpfile 'java.0.wmv' -vf scale=320:240.
027b0720c295b93e4abb183" />

这是我从脚本中获得的输出。

MPlayer SVN-r31918 (C) 2000-2010 MPlayer Team
Can't open joystick device /dev/input/js0: No such file or directory
Can't init input joystick
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing mms://s3fwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=C6527A33-587F-4148-A3D2-E7EDED51316B&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183.
STREAM_ASF, URL: mms://s3fwm.castup.net/server12/16/798/79837168-61.wmv?ct=IL&rg=BZ&aid=16&ts=0&cu=C6527A33-587F-4148-A3D2-E7EDED51316B&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183&cuud=user:77f6c69526b9fa05f78d3d6679630308d324d1043027b0720c295b93e4abb183
Resolving s3fwm.castup.net for AF_INET6...

Couldn't resolve name for AF_INET6: s3fwm.castup.net
Resolving s3fwm.castup.net for AF_INET...
Connecting to server s3fwm.castup.net[212.179.13.65]: 1755...

Connected
file object, packet length = 6100 (6100)
unknown object
unknown object
unknown object
stream object, stream ID: 1
stream object, stream ID: 2
unknown object
data object
mmst packet_length = 6100
Cache size set to 64 KBytes
Stream not seekable!

这是预期的输出。

Answer 1

你试过这个吗？

mplayer "$address" -dumpstream -dumpfile "$2.wmv" -vf "scale=320:240" > /dev/null

bash 的 secret :

• 双引号内的变量被展开；单引号内的内容不是。
• 引号内的单词被视为单个标记。
• 一种类型的引号会转义另一种类型的引号。

原行

mplayer "'$address' -dumpstream -dumpfile '$2.wmv' -vf scale\=320\:240" > /dev/null

使用单个参数'$address' -dumpstream -dumpfile '$2.wmv' -vf scale\=320\:240调用mplayer，但是 mplayer 希望每个标记都是一个单独的单词。