Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Programming
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Databases
Mail Systems
openSolaris
Eclipse Documentation
Techotopia.com
Virtuatopia.com
Answertopia.com

How To Guides
Virtualization
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Windows
Problem Solutions
Privacy Policy

  




 

 

Previous: Formatting Numbers, Up: Locales


7.8 Yes-or-No Questions

Some non GUI programs ask a yes-or-no question. If the messages (especially the questions) are translated into foreign languages, be sure that you localize the answers too. It would be very bad habit to ask a question in one language and request the answer in another, often English.

The GNU C library contains rpmatch to give applications easy access to the corresponding locale definitions.

— Function: int rpmatch (const char *response)

The function rpmatch checks the string in response whether or not it is a correct yes-or-no answer and if yes, which one. The check uses the YESEXPR and NOEXPR data in the LC_MESSAGES category of the currently selected locale. The return value is as follows:

1
The user entered an affirmative answer.
0
The user entered a negative answer.
-1
The answer matched neither the YESEXPR nor the NOEXPR regular expression.

This function is not standardized but available beside in GNU libc at least also in the IBM AIX library.

This function would normally be used like this:

       ...
       /* Use a safe default.  */
       _Bool doit = false;
     
       fputs (gettext ("Do you really want to do this? "), stdout);
       fflush (stdout);
       /* Prepare the getline call.  */
       line = NULL;
       len = 0;
       while (getline (&line, &len, stdout) >= 0)
         {
           /* Check the response.  */
           int res = rpmatch (line);
           if (res >= 0)
             {
               /* We got a definitive answer.  */
               if (res > 0)
                 doit = true;
               break;
             }
         }
       /* Free what getline allocated.  */
       free (line);

Note that the loop continues until an read error is detected or until a definitive (positive or negative) answer is read.


 
 
  Published under the terms of the GNU General Public License Design by Interspire