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man pages section 3: Basic Library Functions

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Updated: Friday, August 13, 2021



runtime_constraint_handler, abort_handler_s, ignore_handler_s, set_constraint_handler_s - Runtime-constraint handler functions for the bounds checking interfaces


#define __STDC_WANT_LIB_EXT1__ 1
#include <stdlib.h>
void abort_handler_s(const char *msg, void *ptr, errno_t error);
void ignore_handler_s(const char *msg, void *ptr, errno_t error);
constraint_handler_t set_constraint_handler_s(
     constraint_handler_t handler);


The runtime-constraint handler APIs are part of the C11 bounds checking interfaces specified in the C11 standard, Annex K. They can be used by the application to manage the actions taken when a library function defined to check for runtime-constraints detects a runtime-constraint violation. When such a function detects a runtime-constraint violation, the currently registered runtime-constraint handler, set using the set_constraint_handler_s() function, will be called. See INCITS/ISO/IEC 9899:2011.

The standard allows for implementation specific features of the abort_handler() and the set_constraint_handler_s() functions. The abort_handler_s() function writes a message on the standard error as follows:

(void) fputs(msg, stderr);
(void) fputc('\n', stderr);

When the handler set by the set_constraint_handler_s() function is called, it is passed a number of arguments in a defined order. Of these, two of the arguments are implementation defined as follows:

The second argument is a pointer to an object defined as:

typedef struct __rcviolation_info {
    const char * __function_name;  /* function detected violation */
    int          __error_raw;      /* _RCVIOLATION_* or errno */
    int          __error;          /* canonical errno */
    long         __pad[8];
} __rcviolation_info_t;

The fourth argument is the default constraint handler used if no calls have been made to the set_constraint_handler_s() function. In this case, the ignore_handler_s() function is the default constraint handler used.

Return Values


No return value


No return value


Returns a pointer to the previously registered handler


Example 1 Calling the Runtime-Constraint Handler

The following example calls the runtime-constraint handler, set by the set_constraint_handler_s() function when a NULL pointer is passed as an argument to tmpfile_s() function.

#include <stdio.h>
#include <stdlib.h>

static errno_t  err;

handler(const char *msg, void *ptr, errno_t err)
        printf("%s and the function exited with error number: %d\n",
            msg, err);

main(int argc, char *argv[])
        FILE            *fptr;

        if ((err = tmpfile_s(&fptr)) == 0)
                printf("tmpfile_s is ok\n");
                printf("tmpfile_s is a failure  %d\n", err);
        err = tmpfile_s(NULL);


See attributes(7) for descriptions of the following attributes:

Interface Stability

None of these functions can be safely used in a multi-threaded program.

See Also

asctime_s(3C), bsearch_s(3C), ctime_s(3C), fopen_s(3C), fprintf_s(3C), freopen_s(3C), fscanf_s(3C), fwscanf_s(3C), fwprintf_s(3C), getenv_s(3C), gets_s(3C), gmtime_s(3C), localtime_s(3C), mbsrtowcs_s(3C), mbstowcs_s(3C), memcpy_s(3C), memmove_s(3C), memset_s(3C), printf_s(3C), qsort_s(3C), scanf_s(3C), snprintf_s(3C), snwprintf_s(3C), sprintf_s(3C), sscanf_s(3C), strcat_s(3C), strcpy_s(3C), strerror_s(3C), strerrorlen_s(3C), strncat_s(3C)), strncpy_s(3C), strnlen_s(3C), strtok_s(3C), swprintf_s(3C), swscanf_s(3C), tmpfile_s(3C), tmpnam_s(3C), vfprintf_s(3C), vfscanf_s(3C), vfwprintf_s(3C), vfwscanf_s(3C), vprintf_s(3C), vscanf_s(3C), vsnprintf_s(3C), vsnwprintf_s(3C), vsscanf_s(3C), vswprintf_s(3C), vswscanf_s(3C), vwscanf_s(3C), vwprintf_s(3C), wcrtomb_s(3C), wcscat_s(3C), wcscpy_s(3C), wcsncat_s(3C), wcsncpy_s(3C), wcsnlen_s(3C), wcsrtombs_s(3C), wcstok_s(3C), wcstombs_s(3C), wctomb_s(3C), wmemcpy_s(3C), wmemmove_s(3C), wprintf_s(3C), wscanf_s(3C), libc(3LIB), standards(7)


These functions, along with the rest of the interfaces specified by Annex K of the C11 standard, were added to Oracle Solaris in the Oracle Solaris 11.4.0 release.