Is anyone aware of a smalltalk library for converting Unicode to ascii?
I'm hoping that it will be somewhat intelligent, i.e. remove diacritical
marks. Non-ascii characters would either be removed or replace with
something like an underscore. E.g.:
"ěščřžýáíé ❤"
would be converted to:
"escrzyaie _"
or:
"escrzyaie "
Thanks,
Alistair
As was clarified in the comments, my goal was to be able to convert
filenames containing non-ascii / non-printable characters into something
that would still be meaningful but only contain ascii characters.
Using the Diacritics library kindly pointed out by Peter I ended up
writing a small class that does the conversion. If you're interested,
it is at:
https://github.com/akgrant43/AkgMiscellaneousUtilities/tree/master/mc/AKG-AsciiFilename.package
Thanks for all the assistance!
Related
I cant think of an OS (Linux, Windows, Unix) where this would cause an issue but maybe someone here can tell me if this approach is undesirable.
I would like to use a base64 encoded string as a filename. Something like gH9JZDP3+UEXeZz3+ng7Lw==. Is this likely to cause issues anywhere?
Edit: I will likely keep this to a max of 24 characters
Edit: It looks like I have a character that will cause issues. My function that generated my string is providing stings like: J2db3/pULejEdNiB+wZRow==
You will notice that this has a / which is going to cause issues.
According to this site the / is a valid base64 character so I will not be able to use a base64 encoded string for a filename.
No. You can not use a base64 encoded string for a filename. This is because the / character is valid for base64 strings which will cause issues with file systems.
https://base64.guru/learn/base64-characters
Alternatives:
You could use base64 and then replace unwanted characters but a better option would be to hex encode your original string using a function like bin2hex().
The official RFC 4648 states:
An alternative alphabet has been suggested that would use "~" as the 63rd character. Since the "~" character has special meaning in some file system environments, the encoding described in this section is recommended instead. The remaining unreserved URI character is ".", but some file system environments do not permit multiple "." in a filename, thus making the "." character unattractive as well.
I also found on the serverfault stackexchange I found this:
There is no such thing as a "Unix" filesystem. Nor a "Windows" filesystem come to that. Do you mean NTFS, FAT16, FAT32, ext2, ext3, ext4, etc. Each have their own limitations on valid characters in names.
Also, your question title and question refer to two totally different concepts? Do you want to know about the subset of legal characters, or do you want to know what wildcard characters can be used in both systems?
http://en.wikipedia.org/wiki/Ext3 states "all bytes except NULL and '/'" are allowed in filenames.
http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx describes the generic case for valid filenames "regardless of the filesystem". In particular, the following characters are reserved < > : " / \ | ? *
Windows also places restrictions on not using device names for files: CON, PRN, AUX, NUL, COM1, COM2, COM3, etc.
Most commands in Windows and Unix based operating systems accept * as a wildcard. Windows accepts % as a single char wildcards, whereas shells for Unix systems use ? as single char wildcard.
And this other one:
Base64 only contains A–Z, a–z, 0–9, +, / and =. So the list of characters not to be used is: all possible characters minus the ones mentioned above.
For special purposes . and _ are possible, too.
Which means that instead of the standard / base64 character, you should use _ or .; both on UNIX and Windows.
Many programming languages allow you to replace all / with _ or ., as it's only a single character and can be accomplished with a simple loop.
In Windows, you should be fine as long if you conform to the naming conventions of Windows:
https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions.
As far a I know, any base64 encoded string does not contain any of the reserves characters.
The thing that is probably going to be a problem is the lengte of the file name.
In Kotlin if we use:
string.split(Regex("\\s+"))
Then we can split a string into words separated by whitespace. However the string:
val string = "a\u2000b"
doesn't split since the regex doesn't match unicode whitespace characters.
I there a way to split the string on all whitespace characters?
Since Java 7 Pattern allows to specify the UNICODE_CHARACTER_CLASS-flag which would basically also work for your current issue:
Pattern.compile("\\s+", Pattern.UNICODE_CHARACTER_CLASS)
Unfortunately this isn't directly supported via RegexOption with Kotlins Regex yet. There is a known issue that also describes a workaround (KT-21094):
string.split("""(?U)\s+""".toRegex())
You (most probably) require Java 7+ for that to actually work. Alternatives could be to use other predefined character classes instead. However, you need to lookup the appropriate Pattern-javadoc for your Java version to ensure that it is actually working (or do it in a trial-error-manner ;-)).
I've used the following regex to match Unicode whitespace:
Regex("[\\p{javaWhitespace}\u00A0\u2007\u202F]+")
This works because while \s matches only Latin-1 whitespace, \p{javaWhitespace} matches everything for which Character.isWhitespace() is true. For some reason, this doesn't include a few particular characters, which I've listed separately.
More info in the docs for Pattern.
Related fact: although java.lang.String.trim() doesn't remove non-breaking spaces or figure spaces, kotlin.String.trim() does!
This is related to
What are the characters that count as the same character under collation of UTF8 Unicode? And what VB.net function can be used to merge them?
This is how I plan to do this:
Use http://msdn.microsoft.com/en-us/library/dd374126%28v=vs.85%29.aspx to turn the string into
KD form.
Basically it'll turn most variation such as superscript into the normal number. Also it decompose tilda and accent into 2 characters.
Next step would be to remove all characters whose sole purpose is tildaing or accenting character.
How do I know which characters are like that? Which characters are just "composing characters"
How do I find such characters? After I find those, how do I get rid of it? Should I scan character by character and remove all such "combining characters?"
For example:
Character from 300 to 362 can be gotten rid off.
Then what?
Combining characters are listed in UnicodeData.txt as having a nonzero Canonical_Combining_Class, and a General_Category of Mn (Mark, nonspacing).
For each character in the string, call GetUnicodeCategory and check the UnicodeCategory for NonSpacingMark, SpacingCombiningMark or EnclosingMark.
You may be able to do it more efficiently using regex, eg Regex.Replace(str, "\p{M}", "").
Our application receives data from various sources. Some of these contain HTML character makeup instead of regular characters. So instead of string "â" we receive string "â".
How can we convert "â" to a character in the database character set using SQL/PLSQL?
Our database is 10GR2.
Unescape_reference and excape_reference I believe is what you're looking for
UTL_I18N.UNESCAPE_REFERENCE('hello < å')
This returns 'hello <'||chr(229).
http://docs.oracle.com/cd/B28359_01/appdev.111/b28419/u_i18n.htm#i998992
You can use the CHR() function to convert an ascii character number to a character representation.
SELECT chr(226)
FROM dual;
CHR(226)
--------
â
For more information see: http://www.techonthenet.com/oracle/functions/chr.php
Hope it helps...
one solution
replace(your_test, 'â', chr(226))
but you'd have to nest many replace functions, one for each entity you need to replace. This might be very slow if you have to replace many.
You can wrote your own function, seqrching for the ampersand and replacing when found.
Have you searched the Oracle Supplied Packages manual? I know they have a function that does the opposite for a few entities.
to convert a column in oracle which contains HTML items to plain text, you could use:
trim(regexp_replace(UTL_I18N.unescape_reference(column_name), '<[^>]+>'))
It will replace HTML character as above stated but will also remove HTML tags en remove leading and trailing spaces.
I hope it will help someone.
I need to display Vietnamese in my APP. But now, i cannot show the words in correct format. For example, the word "&#code" i cannot convert it to Vietnamese, it just display "&#code;".
Does anyone can help me how to handle the word in unicode ?
Thanks a lot!
Tisa
Just write the unicode string inside #"..." without quoting. Strictly speaking, that's non-portable, but as long as you use it for just for Objective-C, it should be OK. It should work on a modern XCode toolchain.
In general, you need to understand that &#... is a way to quote unicode character in HTML, not in a C-string. In C, if you want to be most portable, you need to use \x escapes. Some newer compilers accept \u... and \U... for unicodes.