I'm attempting to use NSRegularExpression to search for a string inside a pbxproj (Inside the .xcodeproj folder).
I'm searching for the compiler flags in the "Begin PBXBuildFile section" area
NSString* findFlagsRegex = #"([A-Z0-9]{24}\\s\\/\\*\\s[A-Za-z\\.\\s0-9]+\\*\\/\\s=\\s{isa\\s\\=\\s[A-Za-z]*;\\s?fileRef\\s\\=\\s[A-Z0-9]*\\s\\/\\*\\s[A-Za-z0-9\\s\\.]*\\*\\/;\\ssettings\\s\\=\\s{[A-Za-z0-9_\\s\\=\"-]*;\\s\\};\\s};)";
NSRegularExpression* expression3 = [NSRegularExpression regularExpressionWithPattern:findFlagsRegex options:kNilOptions error:&err];
NSLog(#"Error: %#",[err description]);
Error Domain=NSCocoaErrorDomain Code=2048 "The value “([A-Z0-9]{24}\s\/\*\s[A-Za-z\.\s0-9]+\*\/\s=\s{isa\s\=\s[A-Za-z]*;\s?fileRef\s\=\s[A-Z0-9]*\s\/\*\s[A-Za-z0-9\s\.]*\*\/;\ssettings\s\=\s{[A-Za-z0-9_\s\="-]*;\s\};\s};)” is invalid." UserInfo=0x61800026a7c0 {NSInvalidValue=([A-Z0-9]{24}\s\/\*\s[A-Za-z\.\s0-9]+\*\/\s=\s{isa\s\=\s[A-Za-z]*;\s?fileRef\s\=\s[A-Z0-9]*\s\/\*\s[A-Za-z0-9\s\.]*\*\/;\ssettings\s\=\s{[A-Za-z0-9_\s\="-]*;\s\};\s};)}
I copy:
([A-Z0-9]{24}\s\/\*\s[A-Za-z\.\s0-9]+\*\/\s=\s{isa\s\=\s[A-Za-z]*;\s?fileRef\s\=\s[A-Z0-9]*\s\/\*\s[A-Za-z0-9\s\.]*\*\/;\ssettings\s\=\s{[A-Za-z0-9_\s\="-]*;\s\};\s};)
The regular expression above works in RegexPal, directly copying it from the invalid value from the error message on the same test data... so I'm not sure what's wrong :/
Not sure if this will add anything, but this is a Mac App and not an iOS app.
Your pattern contains a lone literal }. I believe you meant to have two literal {s and two literal }s - this is a slightly modified version of the pattern you had in your question, with three more \\s inserted to escape the curly braces that are currently not escaped in your code.
NSString* findFlagsRegex = #"([A-Z0-9]{24}\\s\\/\\*\\s[A-Za-z\\.\\s0-9]+\\*\\/\\s=\\s\\{isa\\s\\=\\s[A-Za-z]*;\\s?fileRef\\s\\=\\s[A-Z0-9]*\\s\\/\\*\\s[A-Za-z0-9\\s\\.]*\\*\\/;\\ssettings\\s\\=\\s\\{[A-Za-z0-9_\\s\\=\"-]*;\\s\\};\\s\\};)";
I'm not sure whether the bug is with RegexPal, or if RegexPal depends on the copy of JS that your browser uses, or if the bug is with NSRegularExpressions, but either way, escaping a character which doesn't need to be escaped shouldn't cause any issues (or at least it's not my understanding of regular expressions that it should.)
Related
I have a little regex problem (don't we all sometimes).
The few pieces of code are from Objective C but regex expressions are still the same I believe.
I have two functions called
NSString * CRLocalizedString(NSString *key)
NSString * CRLocalizedArgString(NSString *key, ...)
These are scattered around my project for localisation.
Now I want to find them all.
Well go to directory, parse all files, etc
All fine there.
The regexes I use on the files are
[NSRegularExpression regularExpressionWithPattern:#"CRLocalizedString\\(#\\\"[^)]+\\\"\\)" options:0 error:&error];
[NSRegularExpression regularExpressionWithPattern:#"CRLocalizedArgString\\([^)]+\\)" options:0 error:&error];
And this works perfect except that my terminates character is an ).
The problem occurs with function calls like this
CRLocalizedString(#"Happy =), o so happy =D");
CRLocalizedArgString(#"Filter (%i)", 0.75f);
The regex ends the string at "Filter (%i" and at "Happy =)".
And this is where my regex knowledge ends and I do not now what to do anymore.
I thought using ");" as an end but this isn't always the case.
So I was hoping someone here knew something for me (complete different things then regex are also allowed of course)
Kind regards
Saren
Let's write your first regex without the extra level of C escapes:
CRLocalizedString\(#\"[^)]+\"\)
You don't have to escape a " for a regex, so let's get rid of those extra backslashes:
CRLocalizedString\(#"[^)]+"\)
So, you want to match a quoted string using "[^)]+". But that doesn't match every quoted string.
What is a quoted string? It's a ", followed by any number of string atoms, followed by another ". What is a string atom? It's any character except " or \, or a \ followed by any character. So here's a regex for a quoted string:
"([^"\\]|\\.)*"
Sticking that back into your first regex, we get this:
CRLocalizedString\(#"([^"\\]|\\.)*"\)
Here's a link to a regex tester demonstrating that regex.
Quoting it in an Objective-C string literal gives us this:
#"CRLocalizedString\\(#\"([^\"\\\\]|\\\\.)*\"\\)"
It is impossible to write a regex to match calls to CRLocalizedArgString in the general case, because such calls can take arbitrary expressions as arguments, and regexes cannot match arbitrary expressions (because they can contain arbitrary levels of nested parentheses, which regexes cannot match).
You could just hope that there are no parentheses in the argument list, and use this regex:
CRLocalizedArgString\(#"([^"\\]|\\.)*"[^)]*\)
Here's a link to a regex tester demonstrating that regex.
Quoting it in an Objective-C string literal gives us this:
#"CRLocalizedArgString\\(#\"([^\"\\\\]|\\\\.)*\"[^)]*\\)"
I've received a Warning in Xcode: Unknown escape sequence '\]'
Code in Question: _regexForFindingTags = [[NSRegularExpression alloc] initWithPattern:#"\[.*?\]" options:ops error:&error];
The Problematic Search Pattern: \[.*?\]
Why is there a Warning for this Specific Search Pattern?
How can this Warning be Overcome?
My Search Pattern works in Regex Tester (granted that's in Javascript). According to Ray Wenderlich's NSRegularExpression Tutorial the ] character should be escapable using the \ character, So I'm missing something...
You get a warning from your compiler that is parsing string literal, not from regex engine. As escaping also exists for string literals, the sequence #"\[" is just syntax error apart from regex' syntax (it is just string after all, right?). So, if original regex is \[.*?\], it must be transformed it into:
[… initWithPattern:#"\\[.*?\\]" …];
I.e. you escape brackets at regex level and then also escape backslashes at string literal level, so #"\\[.*?\\]" becomes \[.*?\] in memory bytes.
You unfortunately need to escape the \
So they need to be \ in NSString literals
I'm writing a program to make text that begins with /* and ends with */ a different color (syntax highlighting for a C comment). When I try this
#"/\*.*\*/";
I get unknown escape sequence. So I figured that to get a literal asterisk I had to use this
#"/[*].*[*]/";
and I get no errors, but when I use this code
commentPattern = #"/[*].*[*]/";
reg = [NSRegularExpression regularExpressionWithPattern:commentPattern options:kNilOptions error:nil];
results = [reg matchesInString:self.string options:kNilOptions range:NSMakeRange(0, [self.string length])];
for (NSTextCheckingResult *result in results)
{
[self setTextColor:[NSColor colorWithCalibratedRed:0.0 green:0.7 blue:0.0 alpha:1.0] range:result.range];
}
the text color of the comments doesn't change, but I don't see anything wrong with my regular expression. Can someone tell me why this wont work? I don't think it's a problem with the way I get the results or change their color, because I use the same method for other regular expressions.
You want to use this: "\\*".
\* is the escape sequence for * in regular expressions, but in C strings, \ also begins an escaped character token, so you have to escape that as well.
#"/\*.*\*/";
I get unknown escape sequence.
A string first converts escape sequences in the string, then the result is handed over to the regex engine. For instance, an escape sequence might be \t, which represents a tab, or \n which represents a newline. The string first converts an escape sequence to a special code. Your error is saying that \* is not a legal escape sequence for an NSString.
The regex engine needs to see a literal back slash followed by a *. To get a literal back slash in a string you need to write \\. However, for readability I prefer using a character class like you did with your second attempt.
You should NSLog what the results array contains to see what matches you are getting. If the matches are what you expect, then the problem is not with the regex.
I would like to show the NSString below on my UILabel:
NSString *strValue=#"你好";
but i can not show it on my UILabel i get strange characters!
I use this code to show the text:
[NSString stringWithCString:[strValue UTF8String] encoding:NSUTF8StringEncoding];
I tried [NSString stringWithCString:[strValue cStringUsingEncoding:NSISOLatin1StringEncoding] encoding:NSUTF8StringEncoding] and it worked
but i can not show emoticons with cStringUsingEncoding:NSISOLatin1StringEncoding so i have to use UTF8String.
Any help appreciated.
Your source file is in UTF-8, but the compiler you are using thinks it's ISO-Latin 1. What you think is the string #"你好" is actually the string #"ä½ å¥½". But when you ask NSString* to give you this back as ISO-Latin 1, and treat it as UTF-8, you've reversed the process the compiler took and you end up with the original string.
One solution that you can use here is to tell your compiler what encoding your source file is in. There is a compiler flag (for GCC it's -finput-charset=UTF-8, not sure about clang) that will tell the compiler what encoding to use. Curiously, UTF-8 should be the default already, but perhaps you're overriding this with a locale.
A more portable solution is to use only ASCII in your source file. You can accomplish this by replacing the non-ASCII chars with a string escape using \u1234 or \U12345678. In your case, you'd use
NSString *strValue=#"\u4F60\u597D";
Of course, once you get your string constant to be correct, you can ditch the whole encoding stuff and just use strValue directly.
UIAlertView *message = [[UIAlertView alloc] initWithTitle:[[LanguageManager sharedLanguageManager] get:#"Notice"]
message:[NSString stringWithFormat:[[LanguageManager sharedLanguageManager] get:#"Notice_Text"]]
delegate:nil
cancelButtonTitle:[[LanguageManager sharedLanguageManager] get:#"Close"]
otherButtonTitles:nil];
Hi, let me explain my codes above. Basically it calls up an UIAlertView with data read from a .plist via my LanguageManager singleton class. The LanguageManager get function basically returns a NSString*. I know I should use the NSLocalizedString class but I had been using this class for a while now, so I had decided to stick to it.
My problem lies with the "message:" parameter. The string I am trying to read contains formatting characters like \n but it does not output correctly and appears as \n instead of a line break when printed. I also get the "Format string is not a string literal" warning. Other parts of the app using similar method to return a string which contains %d or %f works correctly though, just the '\n' character not working.
Does anyone have any idea how I may overcome this?
"\n" is not a "formatting character": the compiler translates it to the appropiate code; the string NEVER contains the "\" and "n" characters.
Thus, if you string comes from a source that is NOT compiled by a (Objective-)C(++) compiler, "\n" will be just the two characters. Nothing will turn them into a newline, unless you do it yourself with something like
NewString=[MyString stringByReplacingOccurrencesOfString:#"\\n" withString:#"\n"];
Note the two different strings: in the first case, "\" prevents the compiler from doing the \n -> newline conversion, while the second string will be an actual newline.
The warning about a non-literal format string is somewhat pointless; I've yet to find a good way to get rid of that one (for now, I just disable it entirely, using -Wno-format-nonliteral on clang++ >= 4.0).