catopen, catclose - open/close a message catalog


   #include <nl_types.h>

   nl_catd catopen(const char *name, int flag);

   int catclose(nl_catd catalog);


   The  function  catopen()  opens a message catalog and returns a catalog
   descriptor.   The  descriptor  remains  valid   until   catclose()   or
   execve(2).    If  a  file  descriptor  is  used  to  implement  catalog
   descriptors, then the FD_CLOEXEC flag will be set.

   The argument name specifies the name  of  the  message  catalog  to  be
   opened.   If  name  specifies  an absolute path (i.e., contains a '/'),
   then name specifies a pathname for the message catalog.  Otherwise, the
   environment  variable NLSPATH is used with name substituted for %N (see
   locale(7)).  It is unspecified whether NLSPATH will be  used  when  the
   process  has  root  privileges.   If  NLSPATH  does  not  exist  in the
   environment, or if a message catalog cannot be opened  in  any  of  the
   paths  specified  by  it,  then an implementation defined path is used.
   This latter default path may depend on the LC_MESSAGES  locale  setting
   when  the  flag  argument  is NL_CAT_LOCALE and on the LANG environment
   variable when the flag argument is 0.  Changing the LC_MESSAGES part of
   the locale may invalidate open catalog descriptors.

   The  flag  argument to catopen() is used to indicate the source for the
   language to use.  If it is set to NL_CAT_LOCALE, then it will  use  the
   current  locale  setting  for  LC_MESSAGES.  Otherwise, it will use the
   LANG environment variable.

   The function  catclose()  closes  the  message  catalog  identified  by
   catalog.   It  invalidates  any  subsequent  references  to the message
   catalog defined by catalog.


   The function catopen() returns a message  catalog  descriptor  of  type
   nl_catd on success.  On failure, it returns (nl_catd) -1 and sets errno
   to indicate the error.  The possible error values include all  possible
   values for the open(2) call.

   The function catclose() returns 0 on success, or -1 on failure.


          May  be  the  source of the LC_MESSAGES locale setting, and thus
          determine the language to use if flag is set to NL_CAT_LOCALE.

   LANG   The language to use if flag is 0.


   For  an  explanation  of  the  terms  used   in   this   section,   see

   │InterfaceAttributeValue       │
   │catopen()  │ Thread safety │ MT-Safe env │
   │catclose() │ Thread safety │ MT-Safe     │


   POSIX.1-2001, POSIX.1-2008.


   The   above   is   the   POSIX.1  description.   The  glibc  value  for
   NL_CAT_LOCALE is 1.  The default path varies, but usually  looks  at  a
   number of places below /usr/share/locale.


   catgets(3), setlocale(3)


   This  page  is  part of release 4.09 of the Linux man-pages project.  A
   description of the project, information about reporting bugs,  and  the
   latest     version     of     this    page,    can    be    found    at


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.