extract a string using regular expression in node - node.js

Question

I'm trying to use exec for a regular expression in node. I know the expression works via testing it with an extension in VSCode but when I run the node app it keeps returning null.`
str = '\r\nProgram Boot Directory: \\SIMPL\\app01\r\nSource File: C:\\DRI\\DRI\\DRI Conf Room v2 20180419aj\r\nProgram File: DRI Conf Room v2 20180419aj.smw\r\n';
var regex = /\Program File:(.*?)\\/;
var matched = regex.exec(str);
console.log(matched);

Answer 1

I think you don't have to escape the \P at the beginning and the string ends with \r\n so you could match that instead of \\ which will match a backslash.
If you don't want the leading whitespace in the first capturing group you could add \s*to match zero or more whitespace characters: /Program File:\s*(.*?)\r\n/
For example:
str = '\r\nProgram Boot Directory: \\SIMPL\\app01\r\nSource File: C:\\DRI\\DRI\\DRI Conf Room v2 20180419aj\r\nProgram File: DRI Conf Room v2 20180419aj.smw\r\n';
var regex = /Program File:(.*?)\r\n/;
var matched = regex.exec(str);
console.log(matched[0]);
console.log(matched[1]);
Demo

Answer 2

You need to use a RegExp constructor:
var str = '\r\nProgram \r\nProgram File: DRI 0180419aj.smw\r\n'
.replace('[\\r,\\n]',''); // removes the new lines before we search
var pattern = 'Program File.+' // write your raw pattern
var re = new RegExp(pattern); // feed that into the RegExp constructor with flags if needed
var result = re.exec(str); // run your search
console.log(result)
Not really sure what your pattern should do, so I just put one there, that matches whatever starts with Program File. If you want all matches, not just the first, just change it to
var re = new RegExp(pattern,'g');
Hope that helps!

Answer 3

The regex syntax you use looks off. Try it like this:
const regex = /^Program File:\s*(.*?)$/gm;
const str = `
Program Boot Directory: \\\\SIMPL\\\\app01
Source File: C:\\\\DRI\\\\DRI\\\\DRI Conf Room v2 20180419aj
Program File: DRI Conf Room v2 20180419aj.smw
`;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}