定期EX pression逃脱bash的变量包含双引号，括号 [英] Escaping bash variables for regular expression containing double quote, parentheses

问题描述

这必须是正则表达式亲明显，但我无法找到任何方式来实现这一目标。

This must be obvious for regex pro, but I can't find any way to accomplish that.

我想分组匹配正前pression该行之后拆分大型SQL文件分成几个的...

I want to split a large sql file into several ones after grouping lines that match a regular expression...

所以我就含有国家codeS的数组。
我有一个700MB的文件，开始在全国code行万。
我想将文件分割成取决于这个国家code的几个文件。

So I got an array containing country codes. I got a 700mb file with thousand of rows starting with the country code. I want to split the file into several files depending on this country code.

例如一个行是：

("ZA", "EN", 11564, "ZA-WC", "Western Cape", "West Coast (DC1)", "Swartland", "", "7310", "Moorreesburg", "", "", -33.15528, 18.65639, "Africa/Johannesburg", "UTC+2", "N"),

所以我想匹配（ZA，
我知道如何通过bash的grep显示它，

So I want to match ("ZA", I know how to grep it through bash,

grep '("ZA"' data.sql

我的问题是，当我想用​​bash脚本迭代和结果封装成一个变种将输出重定向到一个文件...我偶然发现了双引号，圆括号逃避...

My problem is when i want to iterate with a bash script and encapsulate result into a var to redirect the output to a file... I stumble upon the double quote, parentheses escaping...

#!/bin/bash

country_code_list_path="country_code.txt"
for country_code in $(cat "$country_code_list_path");
do echo $country_code;
result=`grep '^\(\""$country_code"\", ' geodata.sql| tail -1`;
echo $result;
done

这导致错误与（或（

任何人有提示或替代解决方案来实现这一目标？

Anyone got hints or alternative solution to accomplish that ?

推荐答案

有两个误区：

1. 单引号内壳中的变量不进行评估。

1. Shell-Variables inside single quotes are not evaluated.

通过的grep 使用

"^(\"${country_code}" 

要匹配字符串。不要逃避（字符数限制。

to match the string. Do not escape the (-character.

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