檢查給定字符串中打開的未轉義引號

Question

我正在構建的應用程序的一部分允許您在交互式終端中評估bash命令。輸入時，該命令運行。我試圖讓它更靈活一些，並允許跨越多行的命令。

我已經檢查了一個尾隨的反斜槓，現在我試圖弄清楚如何判斷是否有一個打開的字符串。我還沒有成功地爲此編寫正則表達式，因爲它也應該支持逃脫的引號。

例如：

echo "this is a 
\"very\" cool quote" 

Answer 1

如果你想要一個字符串（subject）相匹配的正則表達式，只有當它不包含不平衡（轉義）報價，然後嘗試以下方法：

/^(?:[^"\\]|\\.|"(?:\\.|[^"\\])*")*$/.test(subject) 

說明：

^   # Match the start of the string. 
(?:  # Match either... 
[^"\\] # a character besides quotes or backslash 
|   # or 
\\.  # any escaped character 
|   # or 
"   # a closed string, i. e. one that starts with a quote, 
(?:  # followed by either 
    \\.  # an escaped character 
|   # or 
    [^"\\] # any other character except quote or backslash 
)*  # any number of times, 
"   # and a closing quote. 
)*   # Repeat as often as needed. 
$   # Match the end of the string.