How to properly escape a double quote in CSV? - csv

Question

I have a line like this in my CSV:
"Samsung U600 24"","10000003409","1","10000003427"
Quote next to 24 is used to express inches, while the quote just next to that quote closes the field. I'm reading the line with fgetcsv but the parser makes a mistake and reads the value as:
Samsung U600 24",10000003409"
I tried putting a backslash before the inches quote, but then I just get a backslash in the name:
Samsung U600 24\"
Is there a way to properly escape this in the CSV, so that the value would be Samsung U600 24" , or do I have to regex it in the processor?

Answer 1

Use 2 quotes:
"Samsung U600 24"""

Answer 2

Not only double quotes, you will be in need for single quote ('), double quote ("), backslash (\) and NUL (the NULL byte).
Use fputcsv() to write, and fgetcsv() to read, which will take care of all.

Answer 3

I have written in Java.
public class CSVUtil {
public static String addQuote(
String pValue) {
if (pValue == null) {
return null;
} else {
if (pValue.contains("\"")) {
pValue = pValue.replace("\"", "\"\"");
}
if (pValue.contains(",")
|| pValue.contains("\n")
|| pValue.contains("'")
|| pValue.contains("\\")
|| pValue.contains("\"")) {
return "\"" + pValue + "\"";
}
}
return pValue;
}
public static void main(String[] args) {
System.out.println("ab\nc" + "|||" + CSVUtil.addQuote("ab\nc"));
System.out.println("a,bc" + "|||" + CSVUtil.addQuote("a,bc"));
System.out.println("a,\"bc" + "|||" + CSVUtil.addQuote("a,\"bc"));
System.out.println("a,\"\"bc" + "|||" + CSVUtil.addQuote("a,\"\"bc"));
System.out.println("\"a,\"\"bc\"" + "|||" + CSVUtil.addQuote("\"a,\"\"bc\""));
System.out.println("\"a,\"\"bc" + "|||" + CSVUtil.addQuote("\"a,\"\"bc"));
System.out.println("a,\"\"bc\"" + "|||" + CSVUtil.addQuote("a,\"\"bc\""));
}
}

Answer 4

Since no one has mentioned the way I usually do it, I'll just type this down. When there's a tricky string, I don't even bother escaping it.
What I do is just base64_encode and base64_decode, that is, encode the value to Base64 before writing the CSV line and when I want to read it, decode.
For your example assuming it's PHP:
$csvLine = [base64_encode('Samsung U600 24"'),"10000003409","1","10000003427"];
And when I want to take the value, I do the opposite.
$value = base64_decode($csvLine[0])
I just don't like to go through the pain.

Answer 5

I know this is an old post, but here's how I solved it (along with converting null values to empty string) in C# using an extension method.
Create a static class with something like the following:
/// <summary>
/// Wraps value in quotes if necessary and converts nulls to empty string
/// </summary>
/// <param name="value"></param>
/// <returns>String ready for use in CSV output</returns>
public static string Q(this string value)
{
if (value == null)
{
return string.Empty;
}
if (value.Contains(",") || (value.Contains("\"") || value.Contains("'") || value.Contains("\\"))
{
return "\"" + value + "\"";
}
return value;
}
Then for each string you're writing to CSV, instead of:
stringBuilder.Append( WhateverVariable );
You just do:
stringBuilder.Append( WhateverVariable.Q() );

Answer 6

If a value contains a comma, a newline character or a double quote, then the string must be enclosed in double quotes. E.g: "Newline char in this field \n".
You can use below online tool to escape "" and , operators.
https://www.freeformatter.com/csv-escape.html#ad-output