Objc-DataFile-Unreadable Substring-Unknown to any encoding - objective-c

I have a DataFile, built by subsidiairy Application. I need to locate some substring contained in the data file. They are identifiable by the character symbols delimiting them. For instance : *!substringqSxt .The substring will vary from a project to another so I need to locate the symbols delimiting them to read the following substring. I also printed the file to different encodings trying which one was used and matched the original data file. found it was MacOsRomanStringEncoding.
I use NSRange:rangOfStringto locate the delimiting symbols. Here is my code :
char *debutAudio ="jjbj";
char *finAudio ="qSxt";
NSString *debutAudioConverted = [[NSString alloc]
initWithCString: debutAudio
encoding:NSMacOSRomanStringEncoding];
NSString *finAudioConverted = [[NSString alloc]
initWithCString: finAudio
encoding:NSMacOSRomanStringEncoding];
NSRange debutaudioRange =[dataFileContent rangeOfString:debutAudioConverted];
NSRange finaudioRange =[dataFileContent rangeOfString:finAudioConverted];
NSLog(#"range is %#",NSStringFromRange(debutaudioRange));
NSLog(#"range is %#",NSStringFromRange(finaudioRange));
Both NSLog returns range is {9223372036854775807, 0}
so not locating the delimiting strings there.
And if I ask to look for other strings contained in the file like "Settings" the rangeOfString will return the proper location and length.
I thought the file may contain multiple encodings, and tried converting with initWithCStringto any possible encoding but nothing would do.
Also if I open the file in text edit and use the "Find" function, it will not locate the delimiting string, but will locate other words. My guts tell me its related. I dont know where to look for info. Could the file be protected, I am reading a copy of it though.

I have found the problem occuring here. The proper encoding is still MacOsRoman. The problem is the prefix string *debutAudio "jjbj"there is actually a tiny space , like a quarter space between each characters. I have tried every unicode spaces listed here :https://www.cs.tut.fi/~jkorpela/chars/spaces.html#adj
without any success. Now I will tried to find some half or quarter space under MacOsRoman see if that is working.

Related

Prevent NSString to escape contents

Sorry for maybe a newbie question.
For various reasons I am stuck with a peculiar string that looks like this:
NSString *myString = #"A\\314\\212A\\314\\210O\\314\\210.jpg";
Can I in some ninja-way remove the double \\ and force NSString understand that the string is Uniencoded and should be read like this
NSString *myString = #"A\314\212A\314\210O\314\210.jpg"; // Displays ÅÄÖ as expected
I have tried different strategies tried to replace all slashes ("\"), but as soon as I add a ("\") NSString adds another one to escape the first one. And I get stuck here...
Is it possible to prevent NSString to escape my string?
UPDATE
I am aware this is a special case. Reading the output from a terminal program which reads files on the users drive. Via a NSTask I am capturing the output to into a NSString for parsing and splitting it into an array. It works great as long as there are no non-ascii characters. HFS+ is encoding non-ascii characters with slightly different Unicode called NFD.
When I am capturing the reponse, the ÅÄÖ are already encoded inside qoutes like this:
file.jpg
file2.jpg
"A\314\212A\314\210O\314\210.jpg"
When I create a NSString and with the captured reponse, it gets escaped by NSString a second time.
A\\314\\212A\\314\\210O\\314\\210.jpg
I am aware that this is not the optimal, but right now I have no control over what the terminal program is outputting. Usually when a NSString is created with this NFD encoding, Objectiv-C takes care of the encoding/decoding for you. But since I have a string with mixed and double escaped content, I have a hard way of creating it and make NSString to understand that the content is encoded with this encoding.
Basically I would like to to this:
decodedString = [output stringByReplacingOccurrencesOfString:#"\\\\"
withString:#"\\"];
But behind the scenes NSString is always escaping \ with another \ for you so I would like a way to create "raw" strings with out NSString interfering.
Have tried various ways to try enforing Unicode encoding on NSString but it all boils down to NSString is always capturing and escaping \.
Any tips och points appreciated!
I did not find any way around this other than go the other way around and change the output from the terminal program not to encode it this way.

How do I remove hidden characters from a NSString?

After copying pasting a text from the web, in my mac app NSTextArea, I see
EE
If I copy these 2 letters in a browser I see:
E?E
If I copy them in google translator I get
E 'E
I cannot identify this character in between the two E. But the question is: how do I remove these hidden characters from my NSString?
In your uploaded file the specific hex code for the hidden character is 0x18
(found via Hex Fiend)
This character, along with others are part of a 'control character set'. The set also contains characters such as the tab (0x09) and newline (0x0A) - obviously those we don't want to remove.
In Objective-C, we can use the NSCharacterSet controlCharacterSet in conjunction with whitespaceAndNewlineCharacterSet to get just the blank characters that have no rendered width.
NSMutableCharacterSet* zeroWidthCharacterSet = [[NSCharacterSet controlCharacterSet] mutableCopy];
[zeroWidthCharacterSet formIntersectionWithCharacterSet:[[NSCharacterSet whitespaceAndNewlineCharacterSet] invertedSet]];
Then we can simply use the good old split by character set method
string = [[string componentsSeparatedByCharactersInSet:zeroWidthCharacterSet] componentsJoinedByString:#""];
Note that if a special character that uses more than one UTF8 character to represent itself (like Emoji) uses 0x18 then stripping it will break the character combo
Because the control characters are special, I don't believe you'd ever find them in an Emoji sequence.

Insert unicode symbol into label from array

I want to insert a unicode symbol for pi, which is \u03c0 into a label and for it to display the symbol. I am loading this in from an array which was read from a txt file. For example if I have a txt file that contains "\u03c0":
string = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil]
array[i] = string;
label.text = array[i];
What am getting is "\u03c0" as an output in the textfield, but I want the symbol. What I am doing wrong?
Edit: it seems that my problems is with string encoding because I am reading in the array from a file. I was using NSUTF8StringEncoding. What should this be changed to to allow unicode?
My guess is the contents of your file contains \\u03c0 rather than the actual character. If you have control of the file contents, paste in the actual character, not the sequence, because the editor will save it with the escaping "\". If you don't have control, i suggest writing code to detect this escaping, strip the preceding "\" and then use the result in your format.

objective c UTF8String not working with japanese

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 #"你好". 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.

objective-c loading data from excel

I'm writing an application for the iPad that will tell us whether or not someone is on court at a tennis tournament. Basically, just an application with a list of names each with an on/off button next to them. Once the on button is pressed, their name turns red, thus they are on court.
Is there any way, to make this easier for myself, I would be able to connect it to my computer and load in a list of names once the application is complete? That would save me from having to individually enter/modify names manually.
Thanks in advance,
Louis.
Though your question is pretty... vague, one suggestion :
importing Spreadsheet-like data could easily be done by import the .csv version (Comma-separated value) of a Spreadsheet.
A comma-separated values (CSV) file stores tabular data (numbers and
text) in plain-text form. Plain text means that the file is a sequence
of characters, with no data that has to be interpreted instead, as
binary numbers. A CSV file consists of any number of records,
separated by line breaks of some kind; each record consists of fields,
separated by some other character or string, most commonly a literal
TAB or comma. Usually, all records have an identical sequence of
fields.
Example :
Year,Make,Model,Length
1997,Ford,E350,2.34
2000,Mercury,Cougar,2.38
Then, you could simply :
(1) Load your csv file as a simple text file
NSString* contents = [NSString stringWithContentsOfFile:filename
encoding:NSUTF8StringEncoding
error:nil];
(2) Get the lines
NSArray* lines = [contents componentsSeparatedByString:#"\n"];
(3) Parse each line's fields
for (NSString* line in lines)
{
NSArray* fields = [line componentsSeparatedByString:#","];
}
This is a CSV problem overall, not specific to this code. Indeed if CSV fields contains commas, this is broken. Happens a lot if your numbers standards uses commas for floating point numbers instead of dots.
I tend to always used CSVs where the field separator is TAB (aka "\t") instead of comma. Much more unlikely to be broken. This is usually configurable in CSV-producing tools such as Excel.