如何让嵌套双引号生存的bash间preTER？ [英] how to make nested double quotes survive the bash interpreter?

问题描述

..

确实任何魔术语法存在，可以在$ WGETOPT的定义被插入以允许$ USERAGENT变量是'吸收'，并且仍然允许用于向wget命令调用如<强>语法1 ？目前我已经开始借助EVAL我不是很满意，但也许这是我能做些什么我想在这里的唯一途径？！

does any magic syntax exist that can be inserted in the definition of $WGETOPT to allow the $USERAGENT variable to be 'absorbed', and still allow for a call to the wget command as in syntax 1? i've currently resorted to using 'eval' which i'm not happy with, but maybe this is the only way i can do what i want to here?!

#params
USERAGENT="Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
PROXYSWITCH=off
WGET=wget
WGETOPT="--cut-dirs=3 -r -l10 -dnv -x -H --timestamping --limit-rate=100K --proxy=$PROXYSWITCH -U \"$USERAGENT\"" 
WGETOPTminusUSERAGENT="-cut-dirs=3 -r -l10 -dnv -x -H --timestamping --limit-rate=100K --proxy=$PROXYSWITCH" 
URL=http://blah

#commands
#1.
    $WGET $WGETOPT $URL
#2.
    $WGET "$WGETOPT" $URL
#3.
    eval "$WGET $WGETOPT $URL"
#4. 
    $WGET $WGETOPTminusUSERAGENT -U "$USERAGENT" $URL

1 即可。结果是：

DEBUG output created by Wget 1.11.4 on Windows-MinGW.
Enqueuing http://(compatible;/ at depth 0
Queue count 1, maxcount 1.
Host `(compatible;' has not issued a general basic challenge.
...
Setting --user-agent (useragent) to "Mozilla/4.0
...

这是显而易见的，为什么，在\\没有'生存'bash的跨preTER。

it's obvious why, the "\" didn't 'survive' the bash interpreter.

2 。结果是：

wget: --cut-dirs: Invalid number `3 -r -l10 -dnv -x -H --timesta.. ..indows NT 5.1)"'.'

在这里，双引号导致传递作为唯一参数，wget的分析从命名参数，然后假设（正确地）剩下的就是它的参数，无论空白。

here, the double-quotes result in a single argument being passed which wget parses a named parameter from, and then assumes (correctly) that the rest is its argument, regardless of white space.

＃3 。作品，我用它，但我记得被严厉谴责使用邪恶/ EVAL！

#3. works, and i'm using it, but i do remember being chastised for using the evil/eval!

＃4 。我假设的作品很好，我没有测试它，因为这不是我想怎么办呢！

#4. i'll assume works fine, i didn't test it because that's not how i want to do it!!

..因此问题。

欢呼声

推荐答案

要放大@伊格纳西奥的回答：如果我了解这里的目标，最好的答案是存储在一个阵列中的选项

To amplify @Ignacio's answer: if I understand the goal here, the best answer is to store the options in an array.

#params
USERAGENT="Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
PROXYSWITCH=off
WGET=wget
WGETOPT=(--cut-dirs=3 -r -l10 -dnv -x -H --timestamping --limit-rate=100K --proxy=$PROXYSWITCH -U "$USERAGENT")

$WGET "${WGETOPT[@]}" "$URL"

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