var phone = #"^\+(?:[0-9] ?){6,14}[0-9]$";
phone will then equal ^\\+(?:[0-9] ?){6,14}[0-9]$
I thought (and the examples I found seem to show) the # character meant to leave my string how I have it. Why is it doubling the \ and how do I stop it?
The visual studio debugger will show it as if it were doubled, since in C# a \ would precede an escape sequence. Don't worry - your string is unchanged.
It only looks like it's doubled in the debug inspectors.
Note that the strings shown in the inspectors don't start with # - they are showing how you would have to write the string if you were to do it without the #. The two forms are equivalent.
If you're really worried about the contents of the string, output it in a console app.
To reiterate in another way, the comparison
var equal = #"^\+(?:[0-9] ?){6,14}[0-9]$" == "^\\+(?:[0-9] ?){6,14}[0-9]$"
will always be true. As would,
var equal = #"\" == "\\";
If you examine the variables using the Text Visualizer, you will be shown the plain unescaped string, as it was when you declared it verbatim.
Related
This question already has answers here:
Can I expand a string that contains C# literal expressions at runtime
(5 answers)
Closed 6 years ago.
I have a literal as a string in a file
def s_CalculatePartiallyUsedTechPenalty(rate):\n total = min(rate,0)\n title = \"Partially Used Technology Penalty\" \n return RateItem(title,total,FinancialUniqueCode.PartiallyUsedTechPenalty,False)
when reading the file the text obviously looks like this:
def s_CalculatePartiallyUsedTechPenalty(rate):\\n total = min(rate,0)\\n title = \\\"Partially Used Technology Penalty\\\" \\n return RateItem(title,total,FinancialUniqueCode.PartiallyUsedTechPenalty,False)
Is there clean way to convert this string so that the value in the file is also the actual value of the string in code. In other words that that \n for example is \n and not \\n.
I understand that I can write a method that goes and replaces all the applicable values, but I do not want to do that unless it is the only way.
Edit: In response to John Wu's answer. No I am not confused. I do understand exactly that this is happening however I want to convert the literal value "\n" to the newline character. So instead of the literal value of \n it should be a new line.
Basically the inverse of How to convert a string containing escape characters to a string
You are confusing yourself. The string held in the file will be exactly the same as the string held in a string variable obtained by reading the file.
Perhaps you are using Visual Studio to inspect the string (i.e. using the Watch window or just hovering over the variable while the code is in debug mode). In this case, Visual Studio will display the extra slash to indicate that the string variable contains the literal value "\n" instead of a newline character.
If you want to eliminate the escape characters in the Watch window, you can append the format specifier ,nq to the variable name (link).
See also this question on StackOverflow.
If you can not fix file-writing code, that you can solve this issues in a following way:
String.Replace(#"\\\", #"\");
String.Replace(#"\\", #"\");
Or, in case, if you normal unescaped string,
String.Replace(#"\\\""", "\"");
String.Replace(#"\\n", Environment.NewLine);
P.s. Also think about other special characters, like \t
UPDATED:
Even better approach:
class Program
{
static void Main(string[] args)
{
var escaped = #"def s_CalculatePartiallyUsedTechPenalty(rate):\n total = min(rate,0)\n title = \""Partially Used Technology Penalty\"" \n return RateItem(title,total,FinancialUniqueCode.PartiallyUsedTechPenalty,False)";
var unescaped = Regex.Unescape(escaped);
Console.WriteLine(unescaped);
}
}
I need to escape chars in a string I have, which content is C:\\blablabla\blabla\\bla\\SQL.exe to C:\blablabla\blabla\bla\SQL.exe so I could throw a process based on this SQL.exe file.
I tried with Mystring.Replace("\\", #"\"); and Mystring.Replace(#"\\", #"\"); but none worked.
How could I do this?
EDITED: Corrected type in string.
I very strongly suspect that you are looking this input string in the Visual Studio debugger and fooling yourself that there are actually 2 \ whereas in reality there aren't. That's the reason why attempting to replace \\ with \ doesn't do anything because in the original string there is no occurrence of \\. And since you are looking the output once again in the debugger, you are once again fooling yourself that there are 2 \.
Visual Studio debugger has this tendency to escape strings. Log it to a file or print to the console and you will see that there is a single \ in your input string and you don't need to replace anything.
It looks like you're trying to replace double backslash (#"\\") in a string with single backslash (#"\"). If so try the following
Mystring = Mystring.Replace(#"\\", #"\");
Note: Are you sure that the string even contains double backslashes? Certain environments will print out a single backslash as a double (debugger for example). Your comment mentioned my approach didn't work. That's a flag that there's not actually a double backslash in your string (else it would work).
The # character specifies a string as a verbatim literal string, but that is when constructing a string. If you use Mystring.Replace("\\", #"\") then nothing will be replaced, essentially, as the two strings are the same.
If you want a string without the escape characters, then either define it with:
string path = #"C:\Some\Directory\And\File.txt";
Or you can replace the \\ with / like so:
path = path.Replace('\\', '/');
It is worth noting, as mentioned by Darin Dimitrov, that the string containing two \ characters is likely just the display of the string (i.e. when using the debugger) and not the actual value of the string.
i think OP is asking how to escape \\ in File Path, if that in the case, as OP is not mentioning where he's trying to use this. so i'm putting a guess.
Then You use Path.Combine() method to get the FileName path.
Path.Combine() Documentation
where are you looking at this output? because it could be the string is what you expect, but viewing the value through the debugger, output window, etc. is escaping the slash
Use something like:
myStr = myStr.Replace(#"\\", #"\");
Make sure you assign the result of Replace method to myStr. Otherwise it goes into void ;)
Try adding "|DataDirectory|\MyFile.xyz" where you need it. It works with connection strings it might work with something else (I haven't really tried to apply it to something else).
I didn't understand what you want, if you just want do get the file name (escape directory chars) you can try:
string fileName = Path.GetFileName(YourString)
Noloman.... when you concatenate are you perhaps missing a "\" when concatenating the directory.. I am assuming that you are trying to join directory + some sub directory.. #noloman keep in mind that in C# "c:\Temp" is written like this "c:\Temp" or #"c:\Temp" one is Literal the other is how to represent a "\" in the legacy way of coding because the "\" is an escape Char and when dealing with directorys we represent all paths and sub paths with "\"
so perhaps by you replacing the "\" you are truly messing up your own expected process
Mystring = Mystring.Replace(#"\\", #"\");
should work for you unless you are truly meaning to do
Mystring = Mystring.Replace(#"\", "\"); which if you believe that you are expecting a "\" to be used to build the directory.. then of course it will not work.. because you have just in essense replaced the backslash with a return char.. I hope that this makes sense to you..
System.IO.Directory.GetCurrentDirectory(); you are using is also an Issue.. SQL Server is not that application thats running the code.. it's your .NET application so you need to either put the location of the SQL Server into a variable, app.config, web.config ect... please edit your question and paste the code that you are using to do what it is that you want to do inregards to the SQL Server Code.. you would probably want to look at the Are you wanting to do something like Process.Start(....) meaning the file name..?
I'm a newbie to c# so hopefully this one isn't too hard for a few of you.
I'm trying to build a string that has a \ in it and I am having difficulty getting just one backslash to show up even though I am adding additional escape chars or ignoring them all together. Can someone show me what I am doing wrong?
What I want my string to look like:
"10.20.14.103\sql08"
What I've tried so far:
I added an additional character to make the compiler happy but it did not escape it.
ip = string.Format("{0}\\\\{1}", ip, instancename); // output has 2 \'s
I told it to ignore escapes, it decided to ignore me instead
string temp = #"192.168.1.200\sql08"; // output has 2 \'s
Can someone help me make sense of this? (The richtext editor here seems to do a better job with it than VS2010 is doing, lol)
I'm guessing you're getting confused by the debugger.
If you hover your mouse over a local variable in VS, strings will be escaped so a single \ will display as \\.
To see what your string really is, output it somewhere for display (e.g., to the console) or hover your mouse on the variable, click on the arrow next to the little magnifying glass that appears, and select "Text Visualizer."
If you're looking at these strings in the debugger (i.e., by hovering the mouse over the variable or using a watch), the debugger adds escape characters to the display string so that it's a valid string expression. If you want to view the string verbatim in this fashion, click on the magnifying glass on the right side of the tooltip or watch entry with the string in it.
I'm guessing you're looking at the values in the debugger and seeing that they have two slashes.
That's normal. The debugger will show two slashes even though the actual string representation will only have one. Just another hump to get over when getting used to the debugger.
Be assured that when you actually use your strings, they will still only have a single slash (using either of your methods).
string requiredString = string.Format(#"{0}\\{1}",str1,str2);
I have a slight problem with a path:
"D:\\Music\\DJ Ti%C3%ABsto\\Tiesto\\Adagio For Strings (Spirit of London).mp3"
"D:\\Music\\Dj Tiësto\\Tiesto\\Adagio For Strings (Spirit of London).mp3"
Currently, when it sends that path to my Audio Library, it cannot open the path. (the reason for it crashing is trying to assign a -1 to a trackbar...but it's irrelevant).
So I'm wondering, is there anyway to prevent C# from switching special characters with %[code]? I've done a .Replace for "[" and "]", but I rather not have to look up every single special character, and add a line of code to prevent it. Is there anyway around this?
Call Uri.UnescapeDataString.
By the way, when putting paths in strings, you can put an # sign before the string to tell the compiler not to process escape codes, like this: #"D:\Music\DJ Tiësto\Tiesto\Adagio For Strings (Spirit of London).mp3". This way, you don't need to double up every backslash.
Can someone explain to me why my code:
string messageBody = "abc\n" + stringFromDatabaseProcedure;
where valueFromDatabaseProcedure is not a value from the SQL database entered as
'line1\nline2'
results in the string:
"abc\nline1\\nline2"
This has resulted in me scratching my head somewhat.
I am using ASP.NET 1.1.
To clarify,
I am creating string that I need to go into the body of an email on form submit.
I mention ASP.NET 1.1 as I do not get the same result using .NET 2.0 in a console app.
All I am doing is adding the strings and when I view the messageBody string I can see that it has escaped the value string.
Update
What is not helping me at all is that Outlook is not showing the \n in a text email correctly (unless you reply of forward it).
An online mail viewer (even the Exchange webmail) shows \n as a new line as it should.
I just did a quick test on a test NorthwindDb and put in some junk data with a \n in middle. I then queried the data back using straight up ADO.NET and what do you know, it does in fact escape the backslash for you automatically. It has nothing to do with the n it just sees the backslash and escapes it for you. In fact, I also put this into the db: foo"bar and when it came back in C# it was foo\"bar, it escaped that for me as well. My point is, it's trying to preserve the data as is on the SQL side, so it's escaping what it thinks it needs to escape. I haven't found a setting yet to turn that off, but if I do I'll let you know...
ASP.NET would use <br /> to make linebreaks. \n would work with Console Applications or Windows Forms applications. Are you outputting it to a webpage?
Method #1
string value = "line1<br />line2";
string messageBody = "abc<br />" + value;
If that doesn't work, try:
string value = "line1<br>line2";
string messageBody = "abc<br>" + value;
Method #2
Use System.Environment.NewLine:
string value = "line1"+ System.Environment.NewLine + "line2";
string messageBody = "abc" System.Environment.NewLine + value;
One of these ways is guaranteed to work. If you're outputting a string to a Webpage (or an email, or a form submit), you'd have to use one of the ways I mentioned. The \n will never work there.
You need to set a watch and see where exactly your database result string gets double escaped.
Adding two strings together will never double escape strings, so its either happening before that, or after that.
When I get the string out of the database, .NET escapes it automagically. However, the little # symbol is appended to the string, which I did not notice.
So it appeared to be non-escaped to my "about to go on holiday" eye inside the ide.
Therefore when the non-escaped \n was added to the string (as the whole string is no longer escaped), it would remove the # and show the database portion of the string escaped.
Gah, it was all an illusion.
Perhaps that holiday is overdue.
Thanks for your input.
If the actual string stored in the database is (spaces added for emphasis): "l i n e 1 \ n l i n e 2", then whatever stored it there probably has a bug. But assuming that is the exact string there, then the "abc\nline1\nline2" string is what happens when you look at the string which would print as "abcline1\nline2" in a debugger which escapes it (this is a convenience, allowing you to copy-paste out of the debugger straight into code without errors).
Short answer: .NET is not escaping the string, your debugger is. The code which writes a literal "\n" into the database has a bug.