linux - 在单引号内转义双引号

Question

for x in $(cat raw_tables.txt)
do
echo '{
    "type" : "jdbc",
    "jdbc" : {
        "url" : "jdbc:mysql://localhost:3306/test",
        "user" : "root",
        "password" : "<pass>",
        "sql" : "select * from "'$x'"",
        "elasticsearch" {
                "cluster" : "Search",
                "host": "<ip>",
                "port": 9300
        },
        "index" : ""'$x'"",
        "type": ""'$x'"" 
    }
}' | java \
   -cp "/etc/elasticsearch/elasticsearch-jdbc-2.3.3.1/lib/*" \
   -Dlog4j.configurationFile=/etc/elasticsearch/elasticsearch-jdbc-2.3.3.1/bin/log4j2.xml \
   org.xbib.tools.Runner \
   org.xbib.tools.JDBCImporter


cat raw_tables.txt
table1
table2
table3

当我运行它时，它显示为

"索引":""$x"",

我需要它以“索引”的形式出现:“$x”，我无法绕过它生成的双引号，如果我尝试用单引号转义整个内容，脚本会认为它已停止。

我已经尝试了一切.. 任何东西都会受到赞赏

谢谢!

Answer 1

使用此处文档，这样您就不必关心引用(在这种情况下，因为文档不需要包含任何反引号或美元符号):

while read x; do
  java ... lots of options \
    more options for java \
    and more options for java  <<END_DOC
{
    "type" : "jdbc",
    "jdbc" : {
        "url" : "jdbc:mysql://localhost:3306/test",
        "user" : "root",
        "password" : "<pass>",
        "sql" : "select * from $x",
        "elasticsearch" {
                "cluster" : "Search",
                "host": "<ip>",
                "port": 9300
        },
        "index" : "$x",
        "type": "$x" 
    }
}
END_DOC
done <raw_tables.txt

结束标记(在本例中为 END_DOC)需要向左对齐，没有缩进。