在shell脚本中执行java程序时使用双引号

Question

我有一个shell脚本，它执行一个Java程序，其中包含从另一个Java程序返回的参数。

java -cp $wekaPath $(java GetFilter $WandFDir) -i $(pwd)/temp/training"$i"_$arffName.arff -o $(pwd)/temp/training_"$i"_$arffName.arff 

回荡时，它产生以下字符串：

java -cp /home/robobenny/Documents/WEKA/weka-3-7-4/weka.jar weka.filters.supervised.attribute.AttributeSelection -E "weka.attributeSelection.InfoGainAttributeEval" -S "weka.attributeSelection.Ranker -T -1.7976931348623157E308 -N 20" -c first -i /home/robobenny/Documents/WEKA/Pipeline/temp/training1_Test.arff -o /home/robobenny/Documents/WEKA/Pipeline/temp/training_1_Test.arff 

这是伟大的，因为如果我的字符串复制到命令行，它运行Java程序没有发生任何事件。问题出现的时候，我不回应，并尝试从shell脚本执行它，我也得到来自终端的以下内容：

<!-- language: lang-none --> 
Can't find class called: "weka.attributeSelection.InfoGainAttributeEval" 
Filter options: 

-S <"Name of search class [search options]"> 
    Sets search method for subset evaluators. 
    eg. -S "weka.attributeSelection.BestFirst -S 8" 
-E <"Name of attribute/subset evaluation class [evaluator options]"> 
    Sets attribute/subset evaluator. 
    eg. -E "weka.attributeSelection.CfsSubsetEval -L" 

Options specific to evaluator weka.attributeSelection.CfsSubsetEval: 

-M 
    Treat missing values as a separate value. 
-L 
    Don't include locally predictive attributes. 

Options specific to search weka.attributeSelection.BestFirst: 

-P <start set> 
    Specify a starting set of attributes. 
    Eg. 1,3,5-7. 
-D <0 = backward | 1 = forward | 2 = bi-directional> 
    Direction of search. (default = 1). 
-N <num> 
    Number of non-improving nodes to 
    consider before terminating search. 
-S <num> 
    Size of lookup cache for evaluated subsets. 
    Expressed as a multiple of the number of 
    attributes in the data set. (default = 1) 

General options: 

-h 
    Get help on available options. 
    (use -b -h for help on batch mode.) 
-i <file> 
    The name of the file containing input instances. 
    If not supplied then instances will be read from stdin. 
-o <file> 
    The name of the file output instances will be written to. 
    If not supplied then instances will be written to stdout. 
-c <class index> 
    The number of the attribute to use as the class. 
    "first" and "last" are also valid entries. 
    If not supplied then no class is assigned. 

当我硬编码的$(java GetFilter $WandFDir)在shell脚本输出：

java -cp $wekaPath weka.filters.supervised.attribute.AttributeSelection -E "weka.attributeSelection.InfoGainAttributeEval" -S "weka.attributeSelection.Ranker -T -1.7976931348623157E308 -N 20" -c first -i $(pwd)/temp/training"$i"_$arffName.arff -o $(pwd)/temp/training_"$i"_$arffName.arff 

它也没有发生事故。有趣的是，当回声时，双引号消失。

java -cp /home/robobenny/Documents/WEKA/weka-3-7-4/weka.jar weka.filters.supervised.attribute.AttributeSelection -E weka.attributeSelection.InfoGainAttributeEval -S weka.attributeSelection.Ranker -T -1.7976931348623157E308 -N 20 -c first -i /home/robobenny/Documents/WEKA/Pipeline/temp/training2_Test.arff -o /home/robobenny/Documents/WEKA/Pipeline/temp/training_2_Test.arff 

当我离开的双引号出$(java GetFilter $WandFDir)我得到以下错误的输出：

<!-- language: lang-none --> 
Illegal options: -T -1.7976931348623157E308 -N 20 
Filter options: 

-S <"Name of search class [search options]"> 
    Sets search method for subset evaluators. 
    eg. -S "weka.attributeSelection.BestFirst -S 8" 
-E <"Name of attribute/subset evaluation class [evaluator options]"> 
    Sets attribute/subset evaluator. 
    eg. -E "weka.attributeSelection.CfsSubsetEval -L" 

Options specific to evaluator weka.attributeSelection.InfoGainAttributeEval: 

-M 
    treat missing values as a seperate value. 
-B 
    just binarize numeric attributes instead 
    of properly discretizing them. 

Options specific to search weka.attributeSelection.Ranker: 

-P <start set> 
    Specify a starting set of attributes. 
    Eg. 1,3,5-7. 
    Any starting attributes specified are 
    ignored during the ranking. 
-T <threshold> 
    Specify a theshold by which attributes 
    may be discarded from the ranking. 
-N <num to select> 
    Specify number of attributes to select 

General options: 

-h 
    Get help on available options. 
    (use -b -h for help on batch mode.) 
-i <file> 
    The name of the file containing input instances. 
    If not supplied then instances will be read from stdin. 
-o <file> 
    The name of the file output instances will be written to. 
    If not supplied then instances will be written to stdout. 
-c <class index> 
    The number of the attribute to use as the class. 
    "first" and "last" are also valid entries. 
    If not supplied then no class is assigned. 

我环顾四周，似乎无法找到任何解决我的问题。

Answer 1

它真的在吸管抓，但是你尝试类似

var="$(java GetFilter $WandFDir)" 
java -cp $wekaPath $var -i $(pwd)/temp/training"$i"_$arffName.arff -o $(pwd)/temp/training_"$i"_$arffName.arff