Alphabet Soup: The Internationalization of Linux, Part 2
A large body of standards has evolved to handle the problems with text manipulation I presented last month. In general, ad hoc handling methods are considered to be localization, while a method that conforms to some standard and is generalizable to many cultural environments is considered internationalization.
Currently, the central standard for internationalization is the locale model of POSIX. Unfortunately, in the current state of the art, localization via the POSIX model is something of a Procrustean bed. For example, in Japanese there are two common ways of notating the currency unit yen: postfixing ¥ and prefixing ¥. It is not uncommon for both conventions to be used in the same document in different contexts: the former is common in running text, the latter in tables. POSIX does not provide for this. It is easy enough to implement by creating a Japanese-table locale to complement the Japanese-text locale, but this places the burden of setting the correct locale on the application programmer. Although much smaller in scale, this burden is much like that imposed by multilingualization. Nor was POSIX designed to support such fine discrimination; this is better left to the individual application anyway.
POSIX-style internationalization provides a comfortable, functional environment for almost all users and applications. Specifically, a POSIX locale determines:
the character set and encoding to be used
classification of characters (e.g., alpha, hex-digit, whitespace, etc.)
the sorting order for strings in the language
digit separator and decimal-point conventions
date and time presentation
message format (in particular, strings for yes and no)
All of these features are implemented by changing the functionality of standard library functions or by adding new ones. That is, the isalpha function in libc no longer consults a fixed table, but instead the table is varied according to the current locale. Displaying monetary values can be done by using the new function strfmon. Unfortunately, the locale support in Linux libc is still only partially documented as of libc-2.0.7t; no man page for strfmon exists, although there is an entry point in the library. A useful discussion by Ulrich Drepper, one of the authors of GNU libc, may be found at http://i44s11.info.uni-karlsruhe.de/~drepper/conf96/paper.html.
The POSIX standard defines a number of levels of compliance with internationalization standards. These levels are a somewhat useful guide to how far an internationalization effort has progressed. Level 1 compliance is achieved when a system is 8-bit clean. Obviously this is a bare minimum, since some characters may get corrupted. Level 2 compliance is achieved when a flexible system for producing localized time, date and monetary formats is implemented. As described above, these facilities are provided by GNU libc, so disciplined use of appropriate formatting functions and the setlocale call is going to be sufficient for most applications to achieve Level 2 compliance. Level 3 compliance is achieved when the application can use localized message catalogs. This facility is provided by the GNU gettext library. Controlling gettext is nearly as simple as setting the locale. Unfortunately, the rules of precedence are somewhat different. However, disciplined use of gettext and its supporting functions will make localization much easier. (See “Internationalizing Messages in Linux Programs” by Pancrazio de Mauro, March 1999.)
Level 4 refers to Asian language support. The Asian languages are given a special status because of the variety of complex subsystems needed to support them. For example, many implementations of X have two separate families of string display functions, one for strings encoded in one byte and another for strings composed of characters encoded in two bytes. In Japanese, one- and two-byte characters are mixed freely, so an internationalized application which needs to deal with Japanese would have to analyze strings into one-byte and two-byte substrings on the fly. In fact, dealing with Japanese by itself forces the programmer to deal with many of the problems posed by true multilingual applications.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide