Cannot split Base64 string the correct way - c#

I'm working on a C# client that receives Base64 files via a website.
It worked sometimes, but now I have a file that doesn't work because:
Lets say I have this as a Base64 string with some extra information added at the beginning shapered.png|data:image/png;base64,iVBORw0KGgoAAAANSUh /// EUgAAACAAAAAgCAYAblabla
Then I do this in the C# code:
var raw = base64.Split('/')[1]; //get raw data with type extention ,
var data = raw.Split(',')[1]; //get base64 data
var info = raw.Split(',')[0]; // gets type extention mp3 base64
var ext = info.Split(';')[0]; // splits header mp3 only use this for comparison against malicous file
var name = base64.Split('|')[0]; //splits name info
Now I see in the debugger that it cuts all the information out after at the ///
Am I completely missing the point?
I'd think that var raw = base64.Split('/')[1] would take the information after date:image/
and then that raw.Split(',')[1] takes out the png;base64 with only the raw data being left.
But it doesn't, it also takes out all the rest after the '/' out in the raw variable resulting in making the file corrupt.
Reason why I'm not splitting it at the ',' immediatly and split from there is to prevent files with a ',' in it to also work.
It totally flew above my head, sorry guys!
I thought in one way that with [1] it would also take the rest of the "array".
string example = "im/noob/programmer";
Console.WriteLine(example);
string lol = example.Split('/')[1]; //this only outputs "noob"
Console.WriteLine(lol);

You are cutting the entire string up in pieces. You use the / to do that splitting and it breaks the string off at every occurrence of a /.
The better solution is to find the position of the slash instead of splitting on it.
Something like this:
string s1 = "shapered.png|data:image/png;base64,iVBORw0KGgoAAAANSUh /// EUgAAACAAAAAgCAYAblabla";
string name = s1.Substring(0, s1.IndexOf('|'));
string data = s1.Substring(s1.IndexOf('|') + 1);
string mimeType = data.Substring(data.IndexOf(':') + 1, data.IndexOf(';') - data.IndexOf(':') - 1);
string base64 = data.Substring(data.IndexOf(',') + 1);
Or when you are comfortable to use a regular expression:
(.*?)\|data:(.*?);base64,(.*)

Related

How to get data from each row of website (DownloadString) by after : char and stop till ; char

I use WebClient and DownloadString to get RAW text file into an string, and I would like to get the first words, like each thing before : char in to a string, AND also the stuff after : but before ; in other string. In this case I want word111 and floor271 in seperate string, and table123 and fan891 into an other string.
The text file looks like this:
word111:table123;
floor271:fan891;
I've tried to look around for days, because I use in my code the Contains method to see if the whole line of text sometimes matches, example word111:table123; if that exists in the raw text file, then the code continues. I looked at Split, IndexOf, and things like that but I don't understand if they can even achieve this goal, because I need them from every row/line, not just one.
WebClient HWIDReader = new WebClient();
string HWIDList = HWIDReader.DownloadString("/*the link would be here, can't share it*/");
if (HWIDList.Contains(usernameBox.Text + ":" + passwordBox.Text))
{
/* show other form because username and password did exist */
}
I expect the code wouldn't work with Split, because it can split the string by : and ; characters tho, but I don't want the usernames and passwords visible in the same string. IndexOf would delete before or after specified characters tho. (Maybe can use IndexOf to both ways? to remove from : till ; is that possible, and how?) Thank you in advance.
You can split the string based on the newline character.
string HWIDList = HWIDReader.DownloadString("/*the link would be here, can't share it*/");
string[] lines = HWIDList.Split('\n');
// NOTE: Should create a hash from the password and compare to saved password hashes
// so that nobody knows what the users' passwords are
string userInput = string.Format("{0}:{1};", usernameBox.Text, passwordBox.Text);
foreach (string pair in lines)
{
if (pair != userInput)
continue;
// found match: do stuff
}

How can I make a string out of a complex URL address

I've been trying to make this URL a workable string in C#, but unfortunately using extra "" or "#" is not cutting it. Even breaking it into smaller strings is proving difficult. I want to be able to convert the entire address into a single string.
this is the full address:
<https://my.address.com/BOE/OpenDocument/opendoc/openDocument.jsp?iDocID=ATTPCi6c.mZInSt5o3t_Xr8&sIDType=CUID&&sInstance=Last&lsMZV_MAT="+URLEncode(""+[Material].[Material - Key])+"&lsIZV_MAT=>
I've also tried this:
string url = #"https://my.address.com/BOE/OpenDocument/opendoc/openDocument.jsp?iDocID=ATTPCi6c.mZInSt5o3t_Xr8&sIDType=CUID&&sInstance=Last&lsMZV_MAT=";
string url2 = #"+ URLEncode("" +[Material].[Material - Key]) + """"";
string url3 = #"&lsIZV_MAT=";
Any help is appreciated.
The simplest solution is put additional quotes inside string literal and use string.Concat to join all of them into single URL string:
string url = #"https://my.address.com/BOE/OpenDocument/opendoc/openDocument.jsp?iDocID=ATTPCi6c.mZInSt5o3t_Xr8&sIDType=CUID&&sInstance=Last&lsMZV_MAT=";
string url2 = #"""+URLEncode(""+[Material].[Material - Key])+""";
string url3 = #"&lsIZV_MAT=";
string resultUrl = string.Concat(url, url2, url3);
NB: You can use Equals method or == operator to check if the generated string matches with desired URL string.
This may be a bit of a workaround rather than an actual solution but if you load the string from a text file and run to a breakpoint after it you should be able to find the way the characters are store or just run it from that.
You may also have the issue of some of the spaces you've added being left over which StringName.Replace could solve if that's causing issues.
I'd recommend first checking what exactly is being produced after the third statement and then let us know so we can try and see the difference between the result and original.
You are missing the triple quotes at the beginning of url2
string url = #"https://my.address.com/BOE/OpenDocument/opendoc/openDocument.jsp?iDocID=ATTPCi6c.mZInSt5o3t_Xr8&sIDType=CUID&&sInstance=Last&lsMZV_MAT=";
string url2 = #"""+URLEncode(""+[Material].[Material - Key])+""";
string url3 = #"&lsIZV_MAT=";
I just made two updates
t&lsMZV_MAT=" to t&lsMZV_MAT="" AND
[Material - Key])+" to [Material - Key])+""
string s = #"<https://my.address.com/BOE/OpenDocument/opendoc/openDocument.jsp?iDocID=ATTPCi6c.mZInSt5o3t_Xr8&sIDType=CUID&&sInstance=Last&lsMZV_MAT=""+ URLEncode([Material].[Material - Key])+""&lsIZV_MAT=>";
Console.Write(s);
Console.ReadKey();

How can i analise millions of strings that merge into each other?

I have millions of strings, around 8GB worth of HEX; each string is 3.2kb in length.
Each of these strings contains multiple parts of data I need to extract.
This is an example of one such string:
GPGGA,104644.091,,,,,0,0,,,M,,M,,*43$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ$GPGGA,104645.091,,,,,0,0,,,M,,M,,*42$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ$GPGGA,104646.091,,,,,0,0,,,M,,M,,*41$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test2ÿÿ3ÿÿ4ÿÿ5ÿÿ6ÿÿ7ÿÿ8ÿÿ9ÿÿ:ÿÿ;ÿÿ<ÿÿ=ÿÿ>ÿÿ?ÿÿ#ÿÿAÿÿBÿÿCÿÿDÿÿEÿÿFÿÿGÿÿHÿÿIÿÿJÿÿ$GPGGA,104647.091,,,,,0,0,,,M,,M,,*40$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header TestKÿÿLÿÿMÿÿNÿÿOÿÿPÿÿQÿÿRÿÿSÿÿTÿÿUÿÿVÿÿWÿÿXÿÿYÿÿZÿÿ[ÿÿ\ÿÿ]ÿÿ^ÿÿ_ÿÿ`ÿÿaÿÿbÿÿcÿÿ$GPGGA,104648.091,,,,,0,0,,,M,,M,,*4F$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Testdÿÿeÿÿfÿÿgÿÿhÿÿiÿÿjÿÿkÿÿlÿÿmÿÿnÿÿoÿÿpÿÿqÿÿrÿÿsÿÿtÿÿuÿÿvÿÿwÿÿxÿÿyÿÿzÿÿ{ÿÿ|ÿÿ$GPGGA,104649.091,,,,,0,0,,,M,,M,,*4E$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test}ÿÿ~ÿÿ.ÿÿ€ÿÿ.ÿÿ‚ÿÿƒÿÿ„ÿÿ…ÿÿ†ÿÿ‡ÿÿˆÿÿ‰ÿÿŠÿÿ‹ÿÿŒÿÿ.ÿÿŽÿÿ.ÿÿ.ÿÿ‘ÿÿ’ÿÿ“ÿÿ”ÿÿ•ÿÿ$GPGGA,104650.091,,,,,0,0,,,M,,M,,*46$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Head
as you can see it is pretty much this repeated:
GPGGA,104644.091,,,,,0,0,,,M,,M,,*43$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ$GPGGA,104645.091,,,,,0,0,,,M,,M,,*42$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ
I want to separate this string into two lists like this:
_GPSList
$GPGGA,104644.091,,,,,0,0,,,M,,M,,*43
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N
_WavList
32HeaderTest.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ
32HeaderTest.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ
Issue 1:
This repetition isn't containing within a single string, it overflows into the next string. so if some data crosses the end and start of two strings how to I deal with that?
Issue 2: How do I analyse the string and extract only the parts I need?
The solution I'm providing is not a complete answer but more like an idea which might help you get what you want.
Everything else which I present is an assumption on my behalf.
//Assuming your data is stored in a file "yourdatafile"
//Splitting all the text on "$" assuming this will separate GPSData
string[] splittedstring = File.ReadAllText("yourdatafile").Split('$');
//I found an extra string lingering in the sample you provided
//because I splitted on "$", so you gotta take that into account
var GPSList = new List<string>();
var WAVList = new List<string>();
foreach (var str in splittedstring)
{
//So if the string contains "Header" we would want to separate it from GPS data
if (str.Contains("Header"))
{
string temp = str.Remove(str.IndexOf("Header"));
int indexOfAsterisk = temp.LastIndexOf("*");
string stringBeforeAsterisk = str.Substring(0, indexOfAsterisk + 1);
string stringAfterAsterisk = str.Replace(stringBeforeAsterisk, "");
WAVList.Add(stringAfterAsterisk);
GPSList.Add("$" + stringBeforeAsterisk);
}
else
GPSList.Add("$" + str);
}
This provides the exact output as you need, only exception is with that extra string. Also some non-standard characters might look like black blocks.

C# cut file Name from Path

I am creating an Image Extraction tool and I am able to retrieve the Images with full path..
For Example:
I need to cut the File name (rss) from path...
I search posts and Tried following
//1.
//string str = s.Split('/', '.')[1];
//2.
string s1;
// string fileName = "abc.123.txt";
int fileExtPos = s.LastIndexOf(".");
if (fileExtPos >= 0)
s1 = s.Substring(0, fileExtPos);
//3.
//var filenames = String.Join(
// ", ",
// Directory.GetFiles(#"c:\", "*.txt")
// .Select(filename =>
//4.
// Path.GetFileNameWithoutExtension(filename)));
None seems to be working
I want the name between "images" and "png" ..What can be the exact code?
Any Suggestion will be helpful
Just use the class Path and its method GetFileNameWithoutExtension
string file = Path.GetFileNameWithoutExtension(s);
Warning: In this context (just the filename without extension and no arguments passed after the URL) the method works well, however this is not the case if you use other methods of the class like GetDirectoryName. In that context the slashes are reversed into Windows-style backslashes "\" and this could be an error for other parts of your program
Another solution, probably more WEB oriented is through the class Uri
Uri u = new Uri(s);
string file = u.Segments.Last().Split('.')[0];
but I find this a lot less intuitive and more error prone.
In your example you're using a uri so you should use System.Uri
System.Uri uri = new System.Uri(s);
string path = uri.AbsolutePath;
string pathWithoutFilename = System.IO.Path.GetDirectoryName(path);
Why use Uri? Because it will handle things like
http://foo.com/bar/file.png#notthis.png
http://foo.com/bar/file.png?key=notthis.png
http://foo.com/bar/file.png#moo/notthis.png
http://foo.com/bar/file.png?key=moo/notthis.png
http://foo.com/bar/file%2epng
Etc.
Here's a fiddle
You should use the various System.IO.Path functions to manipulate paths as they work cross platform. Similarly you should use the System.Uri class to manipulate Uris as it will handle all the various kinds of edge cases like escaped characters, fragments, query strings, etc.

How to retrieve the locale(country) code from URL?

I have a URL, which is like http://example.com/UK/Deal.aspx?id=322
My target is to remove the locale(country) part, to make it like http://example.com/Deal.aspx?id=322
Since the URL may have other similar formats like: https://ssl.example.com/JP/Deal.aspx?id=735, using "substring" function is not a good idea.
What I can think about is to use the following method for separating them, and map them back later.
HttpContext.Current.Request.Url.Scheme
HttpContext.Current.Request.Url.Host
HttpContext.Current.Request.Url.AbsolutePath
HttpContext.Current.Request.Url.Query
And, suppose HttpContext.Current.Request.Url.AbsolutePath will be:
/UK/Deal.aspx?id=322
I am not sure how to deal with this since my boss asked me not to use "regular expression"(he thinks it will impact performance...)
Except "Regular Expression", is there any other way to remove UK from it?
p.s.: the UK part may be JP, DE, or other country code.
By the way, for USA, there is no country code, and the url will be http://example.com/Deal.aspx?id=322
Please also take this situation into consideration.
Thank you.
Assuming that you'll have TwoLetterCountryISOName in the Url. yYou can use UriBuilder class to remove the path from Uri without using the Regex.
E.g.
var originalUri = new Uri("http://example.com/UK/Deal.aspx?id=322");
if (IsLocaleEnabled(sourceUri))
{
var builder = new UriBuilder(sourceUri);
builder.Path
= builder.Path.Replace(sourceUri.Segments[1] /* remove UK/ */, string.Empty);
// Construct the Uri with new path
Uri newUri = builder.Uri;;
}
Update:
// Cache the instance for performance benefits.
static readonly Regex regex = new Regex(#"^[aA-zZ]{2}\/$", RegexOptions.Compiled);
/// <summary>
/// Regex to check if Url segments have the 2 letter
/// ISO code as first ocurrance after root
/// </summary>
private bool IsLocaleEnabled(Uri sourceUri)
{
// Update: Compiled regex are way much faster than using non-compiled regex.
return regex.IsMatch(sourceUri.Segments[1]);
}
For performance benefits you must cache it (means keep it in static readonly field). There's no need to parse a pre-defined regex on every request. This way you'll get all the performance benefits you can get.
Result - http://example.com/Deal.aspx?id=322
It all depends on whether the country code always has the same position. If it's not, then some more details on the possible formats are required.. Maybe you could check, if the first segment has two chars or something, to be sure it really is a country code (not sure if this is reliable though). Or you start with the filename, if it's always in the format /[optionalCountryCode]/deal.aspx?...
How about these two approaches (on string level):
public string RemoveCountryCode()
{
Uri originalUri = new Uri("http://example.com/UK/Deal.aspx?id=322");
string hostAndPort = originalUri.GetLeftPart(UriPartial.Authority);
// v1: if country code is always there, always has same position and always
// has format 'XX' this is definitely the easiest and fastest
string trimmedPathAndQuery = originalUri.PathAndQuery.Substring("/XX/".Length);
// v2: if country code is always there, always has same position but might
// not have a fixed format (e.g. XXX)
trimmedPathAndQuery = string.Join("/", originalUri.PathAndQuery.Split('/').Skip(2));
// in both cases you need to join it with the authority again
return string.Format("{0}/{1}", hostAndPort, trimmedPathAndQuery);
}
If the AbsolutePath will always have the format /XX/...pagename.aspx?id=### where XX is the two letter country code, then you can just strip off the first 3 characters.
Example that removes the first 3 characters:
var targetURL = HttpContext.Current.Request.Url.AbsolutePath.Substring(3);
If the country code could be different lengths, then you could find the index of the second / character and start the substring from there.
var sourceURL = HttpContext.Current.Request.Url.AbsolutePath;
var firstOccurance = sourceURL.IndexOf('/')
var secondOccurance = sourceURL.IndexOf('/', firstOccurance);
var targetURL = sourceURL.Substring(secondOccurance);
The easy way would be to treat as string, split it by the "/" separator, remove the fourth element, and then join them back with the "/" separator again:
string myURL = "https://ssl.example.com/JP/Deal.aspx?id=735";
List<string> myURLsplit = myURL.Split('/').ToList().RemoveAt(3);
myURL = string.Join("/", myURLsplit);
RESULT: https://ssl.example.com/Deal.aspx?id=735

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