Regex, match string 4 or 5 digits long between "\" and "\"

Question

I need to build a regex. the string i want to match always starts with \ then 4 or 5 numbers then another \

For example.

1. Welcome Home<\217.163.24.49\7778\False,
2. Euro Server\217.163.26.20\7778\False,
3. Instagib!)\85.236.100.115\8278\False,

in first example i need "7778". In second example i need "7778". In third example i need "8278".

these 4 digit numbers is actually a port number, and its the only time on each line that this series of characters (eg, \7778\ ) would appear. sometimes the port number is 4 digits long, sometimes its 5.

I already know how to keep the string for later use using Regex.Match.Success, its just the actual regex pattern I am looking for here.

thanks

Answer 1

Try (\\[\d]{4,5}\\)

Answer 2

@"\\(\d{4,5})\\"

\\ to match a backslash, \d to match digits, {4,5} for "4 to 5". The parentheses around \d{4,5} make it so that you can access the number part with .Groups[1].

Answer 3

I've developed a simple tool to verify regexes against example strings; this is a valid string for your samples in C#, it however is not 'strict'!

(?<name>.+?)\\(?<ip>[0-9.]+)\\(?<port>[0-9]{4,5})\\(?<boolean>[False|True]+)

Answer 4

\\[0-9]{4,5}\\

\ It should start with \ (another \ is to escape)
[0-9] It could be any of the number mentioned in set (0,1,2,3...9)
{4,5} previous set can appear 4 to 5 times
\ It should end with \ (another \ is to escape)

Answer 5

var match=Regex.Match(@"\1234\",@"\\(?<num>\d{4,5})\\"); \\"to fix SO syntax highlighter


if(match.Success)
{
    var numString=match.Groups["num"].Value;
}

or (if you don't like using groups) you can use lookbehind and lookahead assertions to ensure your 4-5 digit match is surrounded by slashes:

var match=Regex.Match(@"\1234\",@"(?<=\\)\d{4,5}(?=\\)"); \\"
if(match.Success)
{
    var numString=match.Value;
}