Sigset: ignoring ctrl-c on Unix

Question

I am trying to get my program to ignore Ctrl+ Con unix, which seems to work, the problem is that it continues to write "Syntax error". Here is the code

extern "C" void ignore( int sig )
{            
    fprintf( stderr, "\n"); // Print a new line
    // This function does nothing except ignore ctrl-c
}

int main()
{           
    // For ctrl-c
    sigset( SIGINT, ignore );

    while (1) {
        getUserInput();
    }      

    return 0;
}

Each time I press Ctrl+ C, it starts again via getUserInput, which is the expected behavior, but it also writes “Syntax error”. I checked, and the ignore function starts, and as soon as it is executed, then it prints an error message, I'm not sure why.

Does anyone have any clues?

Many thanks,

Jary

Answer 1

sigset(). POSIX 2008, , .

signal(), ISO C, , sigaction(), POSIX.

- , , - , (, SIGCHLD ).

, , signal():

if (signal(SIGINT, SIG_IGN) != SIG_IGN)
    signal(SIGINT, ignore);

, sigaction():

struct sigaction new_sa;
struct sigaction old_sa;
sigfillset(&new_sa.sa_mask);
new_sa.sa_handler = SIG_IGN;
new_sa.sa_flags = 0;

if (sigaction(SIGINT, &new_sa, &old_sa) == 0 && old_sa.sa_handler != SIG_IGN)
{
    new_sa.sa_handler = ignore;
    sigaction(SIGINT, &new_sa, 0);
}

getUserInput(), , " ". , , , , , .

Answer 2

(: , , signal() ( C) sigaction() (POSIX) sigset(), , .)

; - , , .

. , read EINTR. , , - getUserInput() .

, SIG_IGN, sigset(), signal() sigaction().

Answer 3

" " getUserInput ( -, , ) - , , , .

, SIG_IGN . sigset(SIGINT, SIG_IGN)

Answer 4

ignore() , .

UNIX, SIGINT , getUserInput(). a SIGINT , getUserInput() stderr, undefined, fprintf() . ( , , , / . " " SIGINT?) CERT GNU libc .

Win32, SIGINT .