I am working on macOS, not iOS, XCode 11.
My app allows in a specific location to enter text. This text can be anything. Once done it exports a csv which will be passed to an external process i cannot influence.
The issue: the external process uses semicolon ";" as a separator (csv is separated differently). If the user writes semicolon the external process will fail.
If I manually add an escaping backslash before each semicolon to the csv and then pass it to the external app it works.
What I need: having each semicolon escaped with ONE backslash in the final csv
What I tried
Escaping the whole text with quotation marks - fail
Escaping semicolons in objective-c before writing csv by trying
stringByReplacingOccurrencesOfString (look for #";" replace with #"\;" - compiler throws a warning that escape character is unknown - fail
Appreciate any help
UPDATE:
I also tried to set a double backslash like #Corbell mentioned but this leads in a double backslash in the exported CSV -> fail
I also tried to set a single backslash by using its unicode character:
[NSString stringWithFormat:#"%C;",0x5C]; --> "\\;"
Also failed and produces two backslashes in the final CSV (where i need ONE only).
In your stringByReplacingOccurencesOfString call, second parameter, try escaping your backslash with a backslash to make it a literal character to insert, i.e. #"\\;" - otherwise the compiler thinks you're trying to specify #"\;" as an escape sequence (backslash-semicolon) which is invalid.
Solved. It was the CSV Parser that added additional escaping characters. Once solved that it worked like a charm.
Related
I want to execute a shell command (I want to touch a file). I use system("shell command") to execute the command.
For example I want to touch the file at path /Users/username/New Folder/. Now I need to convert the NSString in a format that is conform to shell commands like /Users/username/New\ Folder.
Is there any method that does a conversion like this?
NOTE: It is NOT just replacing a whitespace with \. If you have a special character in the path like /Users/username/Folder(foo)/ the "shell path" looks like this /Users/username/Folder\(foo\)/
There is no need to convert the path, you can surround it in single quotes. Just use:
touch 'path'
You can enclose the parameters that contain spaces with " " marks.
touch "/Users/username/New Folder/"
At least this works at the shell prompt
Don't use system. It's insecure and unpredictable. Surrounding the string with quotes is not sufficient.
Use the execve style functions instead. They are simple and secure.
I have a column in my database that contains a string like this:
"Warning set for 7 days.\nCritical Notice - Last Time Machine backup was 118 days ago at 2012-11-16 20:40:52\nLast Time Machine Destination was FreeAgent GoFlex Drive\n\nDefined Destinations:\nDestination Name: FreeAgent GoFlex Drive\nBackup Path: Not Specified\nLatest Backup: 2012-11-17"
I am displaying this data in an e-mail to users. I have be able to easily format the field in my html e-mails perfectly by doing the following:
simple_format(#servicedata.service_exit_details.gsub('\n', '<br>'))
The above code replaces the "\n" with "<br>" tags and simple_format handles the rest.
My issues arises with how to format it properly in the plain text template. Initially I thought I could just call the column, seeing as it has "\n" I assumed the plain text would interpret and all would be well. However this simply spits out the string with "\n" intact just as displayed above rather than created line breaks as desired.
In an attempt to find a way to parse the string so the line breaks are acknowledged. I have tried:
#servicedata.service_exit_details.gsub('\n', '"\r\n"')
#servicedata.service_exit_details.gsub('\n', '\r\n')
raw #servicedata.service_exit_details
markdown(#servicedata.service_exit_details, autolinks: false) # with all the necessary markdown setup
simple_format(#servicedata.service_exit_details.html_safe)
none of which worked.
Can anyone tell me what I'm doing wrong or how I can make this work?
What I want is for the plain text to acknowledge the line breaks and format the string as follows:
Warning set for 7 days.
Critical Notice - Last Time Machine backup was 118 days ago at 2012-11-16 20:40:52
Last Time Machine Destination was FreeAgent GoFlex Drive
Defined Destinations:
Destination Name: FreeAgent GoFlex Drive
Backup Path: Not Specified\nLatest Backup: 2012-11-17"
I see.
You need to differentiate a literal backslash followed by a letter n as a sequence of two characters, and a LF character (a.k.a. newline) that is usually represented as \n.
You also need to distinguish two different kinds of quoting you're using in Ruby: singles and doubles. Single quotes are literal: the only thing that is interpreted in single quotes specially is the sequence \', to escape a single quote, and the sequence \\, which produces a single backslash. Thus, '\n' is a two-character string of a backslash and a letter n.
Double quotes allow for all kinds of weird things in it: you can use interpolation with #{}, and you can insert special characters by escape sequences: so "\n" is a string containing the LF control character.
Now, in your database you seem to have the former (backslash and n), as hinted by two pieces of evidence: the fact that you're seeing literal backslash and n when you print it, and the fact that gsub finds a '\n'. What you need to do is replace the useless backslash-and-n with the actual line separator characters.
#servicedata.service_exit_details.gsub('\n', "\r\n")
I am using CMake to build my project and I have the following line:
include_directories(${LLVM_INCLUDE_DIRS})
which, after evaluating LLVM_INCLUDE_DIRS, evaluates to:
include_directories(C:\Program Files\LLVM\include)
The problem is that this is being considered two include directories, "C:\Program" and "Files\LLVM\include".
Any idea how can I solve this problem? I tried using quotation marks, but it didn't work.
EDIT: It turned out that the problem is in the file llvm-3.0\share\llvm\cmake\LLVMConfig.cmake. I enclosed the following paths with quotation marks and the problem was solved:
set(LLVM_INSTALL_PREFIX C:/Program Files/LLVM)
set(LLVM_INCLUDE_DIRS ${LLVM_INSTALL_PREFIX}/include)
set(LLVM_LIBRARY_DIRS ${LLVM_INSTALL_PREFIX}/lib)
In CMake,
whitespace is a list separator (like ;),
evaluating variable names basically replaces the variable name with its content and
\ is an escape character (to get the symbol, it needs to be escaped as well)
So, in your example, include_directories(C:\\Pogram Files\\LLVM\\include) is the same as
include_directories( C:\\Program;Files\\LLVM\\include)
that is, a list with two items. To avoid this, either
escape the whitespace as well:
include_directories( C:\\Program\ Files\\LLVM\\include) or
surround the path with quotation marks:
include_directories( "C:\\Program Files\\LLVM\\include")
Obviously, the second option is the better choice as it is
simpler and easier to read and
can be used with variable evaluation like in your example (since the result of the evaluation is then surrounded by quotation marks and thus, treated a single item)
include_directories("${LLVM_INCLUDE_DIRS}")
This works as well, if LLVM_INCLUDE_DIRS is a list of multiple directories because the items in this list will then be explicitly separated by ; so that there is no need for unquoted whitespace as implicit list item separator.
Side note:
When using hard-coded path-names (for whatever reason) in my CMake files, I usually uses forward slashes as directory separators as this works on Windows as well and avoids the need to escape all backslashes.
This is more likely to be an error at the point where LLVM_INCLUDE_DIRS is set rather than a problem with include_directories.
To check this, try calling include_directories("C:\\Program Files\\LLVM\\include") - it should work correctly.
The problem seems to be that LLVM_INCLUDE_DIRS was constructed without using quotation marks. Try for example running this:
set(LLVM_INCLUDE_DIRS C:\\Program Files\\LLVM\\include)
message("${LLVM_INCLUDE_DIRS}")
set(LLVM_INCLUDE_DIRS "C:\\Program Files\\LLVM\\include")
message("${LLVM_INCLUDE_DIRS}")
The output is:
C:\Program;Files\LLVM\include
C:\Program Files\LLVM\include
Note the semi-colon in the first output line. This is a list with 2 items.
So the way to fix this is to modify the way in which LLVM_INCLUDE_DIRS is created.
Alright, I'm trying to write some code that removes words that contain an apostrophe from an NSString. To do this, I've decided to use regular expressions, and I wrote one, that I tested using this website: http://rubular.com/r/YTV90BcgoQ
Here, the expression is: \S*'+\S
As shown on the website, the words containing an apostrophe are matched. But for some reason, in the application I'm writing, using this code:
sourceString = [sourceString stringByReplacingOccurrencesOfRegex:#"\S*'+\S" withString:#""];
Doesn't return any positive result. By NSLogging the 'sourceString', I notice that words like 'Don't' and 'Doesn't' are still present in the output.
It doesn't seem like my expression is the problem, but maybe RegexKitLite doesn't accept certain types of expressions? If someone knows what's going on here, please enlighten me !
Literal NSStrings use \ as an escape character so that you can put things like newlines \n into them. Regexes also use backslashes as an escape character for character classes like \S. When your literal string gets run through the compiler, the backslashes are treated as escape characters, and don't make it to the regex pattern.
Therefore, you need to escape the backslashes themselves in your literal NSString, in order to end up with backslashes in the string that is used as the pattern: #"\\S*'+\\S".
You should have seen a compiler warning about "Unknown escape sequence" -- don't ignore those warnings!
i have a problem in inserting the listbox value into mysql database in vb 2008 i.e
if i select a video file i.e D:\videos\video1.mpg and add a msgbox() event before inserting into data base it shows the exact path i.e D:\videos\video1.mpg but when i check my database it shows me as D:videosvideo1.mpg how can i solve that
Within MySQL string values the backslash is interpreted as an escape character. The following escape sequences have special meaning to MySQL: \0, \', \", \b, \n, \r, \t, \z, \, \%, \_. Any other character preceeded by a backslash is just replaced with that character. So in your example: \v is not a valid escape sequence so it is replaced with just "v" when it is stored. You should alter your path values to contain the "\" sequence to actually store a backslash. Example: D:\\videos\\video1.mpg
try to insert path with two backslash signs, for example "D:\\videos\\video1.mpg" into database.