A simple code snippet of WIFSIGNALED and WTERMSIG

**meili100** · 11-09-2007

Here is the code:

Code:

int wrapSystem(const std::string& cmd){

 	int ret = system(cmd.c_str());
 	if (WIFSIGNALED(ret) &&
	(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))
		return -1;
 	else
		return ret;
}

Why should we add the line

if (WIFSIGNALED(ret) &&
(WTERMSIG(ret) == SIGINT || WTERMSIG(ret) == SIGQUIT))

What does that do?

**Salem** · 11-09-2007

Well do you want to know whether the program you ran exited normally, or was killed off by the user ?

**matsp** · 11-09-2007

The WIFSIGNALED() returns true if the application stopped due to a "signal".

If it did, the next part checks if the signal itself was SIGINT or SIGQUIT, in which case -1 is returned. SIGINT is "CTRL-C" and SIGQUIT is some other "user-input to abort", often CTRL-\ on various systems.

--
Mats

**brewbuck** · 11-09-2007

Originally Posted by matsp

often CTRL-\ on various systems.

I learn something new every day.

**matsp** · 11-09-2007

Originally Posted by brewbuck

I learn something new every day.

I didn't know that either until I saw it on:
http://en.wikipedia.org/wiki/SIGQUIT

--
Mats

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A simple code snippet of WIFSIGNALED and WTERMSIG