error: invalid operands to binary &

[muthu]

In the following code it gives the error "error: invalid operands to
binary &"
Why it is happening

#include <signal.h>
#include <errno.h>

#define SIGBAD(signo) ((signo) <= 0 || (signo) >= NSIG)
/* <signal.h> usually defines NSIG to include signal number 0 */

int
sigaddset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set |= 1 << (signo - 1); // error
return(0);
}

int
sigdelset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set &= ~(1 << (signo - 1)); // error
return(0);
}

int
sigismember(const sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

return( (*set & (1 << (signo - 1))) != 0 ); //error
}

please give me the solution


With Regards,
Sureshlingam

 

[ankisharma]

In the following code it gives the error "error: invalid operands to
binary &"
Why it is happening

#include <signal.h>
#include <errno.h>

#define SIGBAD(signo) ((signo) <= 0 || (signo) >= NSIG)
/* <signal.h> usually defines NSIG to include signal number 0 */

int
sigaddset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set |= 1 << (signo - 1); // error
return(0);
}

int
sigdelset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set &= ~(1 << (signo - 1)); // error
return(0);
}

int
sigismember(const sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

return( (*set & (1 << (signo - 1))) != 0 ); //error
}

please give me the solution


With Regards,
Sureshlingam

I suppose problem is with sigset_t data type because this could be
implemented as integer type or a strucure type. In your case it seems
that it is defined as a structure.

 

[spibou]

In the following code it gives the error "error: invalid operands to
binary &"
Why it is happening

#include <signal.h>
#include <errno.h>

#define SIGBAD(signo) ((signo) <= 0 || (signo) >= NSIG)
/* <signal.h> usually defines NSIG to include signal number 0 */

int
sigaddset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set |= 1 << (signo - 1); // error
return(0);
}

int
sigdelset(sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

*set &= ~(1 << (signo - 1)); // error
return(0);
}

int
sigismember(const sigset_t *set, int signo)
{
if (SIGBAD(signo)) { errno = EINVAL; return(-1); }

return( (*set & (1 << (signo - 1))) != 0 ); //error
}

please give me the solution


With Regards,
Sureshlingam

*set is of type sigset_t which on my system is a structure.
You cannot apply the binary operators to structures. But
to be sure check how sigset_t is defined on your system.

Spiros Bousbouras

 

[lawrence.jones]

*set is of type sigset_t which on my system is a structure.
You cannot apply the binary operators to structures.

You need to use sigaddset(), sigdelset(), and friends to manipulate a
sigset_t.

-Larry Jones

Monopoly is more fun when you make your own Chance cards. -- Calvin

 

[Keith Thompson]

You need to use sigaddset(), sigdelset(), and friends to manipulate a
sigset_t.

And if you have more questions about these functions, you need to ask
elsewhere, probably in comp.unix.programmer. (This is addressed to
the OP, not to spibou or lawrence.jones.)