UI::Util::Sys Namespace Reference

Namespace for system/library calls. More...

Data Structures
class	Exception
	Use this exception class if you want to catch failures on system/library calls. More...

Functions
uid_t	fsidFromProcfs (pid_t const pid, std::string const &lineId)

Detailed Description

Namespace for system/library calls.

Purpose

• Error handling via exceptions (so no if-err-then-throw-style code needs to be repeated).
• Automatically produce readable error strings from "errno" value in exception strings.
• Transport a copy of the "errno" value up in exception object for detailed error handling if needed.
• Configuration for different systems (linux,win32; ideally, there should be no ifdefs needed but in Sys.?pp).

If you use a call that matches any of the points above, please include a wrapper here.

Example usage

Call any of the wrapper somewhere in your code:

...
myStr = getPath();
UI::Util::Sys::remove(myStr);
// as usual, assume success
...

Somewhere in your context-specific exception handler:

...
catch (UI::Util::Sys::Exception const & e)
{
  std::cerr << "System error        : " << e.what() << std::endl;
  std::cerr << "Errno error code was: " << e.getCode() << std::endl;
  std::cerr << "Exception debug     : " << e.getDebug() << std::endl;
}
...

How to add wrappers

• Use syntax & name from the man page.
• If return value is only used for error condition:yes/no: make it return void.
• Just call the system/library function. On error condition (see man page), use UI_THROW_ERRNO("MY NICE PREFIX") to throw w/ errno + errno text support in the exception.