cert-err33-c¶

Warns on unused function return values. Many of the standard library functions return a value that indicates if the call was successful. Ignoring the returned value can cause unexpected behavior if an error has occurred. The following functions are checked:

• aligned_alloc()
• asctime_s()
• at_quick_exit()
• atexit()
• bsearch()
• bsearch_s()
• btowc()
• c16rtomb()
• c32rtomb()
• calloc()
• clock()
• cnd_broadcast()
• cnd_init()
• cnd_signal()
• cnd_timedwait()
• cnd_wait()
• ctime_s()
• fclose()
• fflush()
• fgetc()
• fgetpos()
• fgets()
• fgetwc()
• fopen()
• fopen_s()
• fprintf()
• fprintf_s()
• fputc()
• fputs()
• fputwc()
• fputws()
• fread()
• freopen()
• freopen_s()
• fscanf()
• fscanf_s()
• fseek()
• fsetpos()
• ftell()
• fwprintf()
• fwprintf_s()
• fwrite()
• fwscanf()
• fwscanf_s()
• getc()
• getchar()
• getenv()
• getenv_s()
• gets_s()
• getwc()
• getwchar()
• gmtime()
• gmtime_s()
• localtime()
• localtime_s()
• malloc()
• mbrtoc16()
• mbrtoc32()
• mbsrtowcs()
• mbsrtowcs_s()
• mbstowcs()
• mbstowcs_s()
• memchr()
• mktime()
• mtx_init()
• mtx_lock()
• mtx_timedlock()
• mtx_trylock()
• mtx_unlock()
• printf_s()
• putc()
• putwc()
• raise()
• realloc()
• remove()
• rename()
• setlocale()
• setvbuf()
• scanf()
• scanf_s()
• signal()
• snprintf()
• snprintf_s()
• sprintf()
• sprintf_s()
• sscanf()
• sscanf_s()
• strchr()
• strerror_s()
• strftime()
• strpbrk()
• strrchr()
• strstr()
• strtod()
• strtof()
• strtoimax()
• strtok()
• strtok_s()
• strtol()
• strtold()
• strtoll()
• strtoumax()
• strtoul()
• strtoull()
• strxfrm()
• swprintf()
• swprintf_s()
• swscanf()
• swscanf_s()
• thrd_create()
• thrd_detach()
• thrd_join()
• thrd_sleep()
• time()
• timespec_get()
• tmpfile()
• tmpfile_s()
• tmpnam()
• tmpnam_s()
• tss_create()
• tss_get()
• tss_set()
• ungetc()
• ungetwc()
• vfprintf()
• vfprintf_s()
• vfscanf()
• vfscanf_s()
• vfwprintf()
• vfwprintf_s()
• vfwscanf()
• vfwscanf_s()
• vprintf_s()
• vscanf()
• vscanf_s()
• vsnprintf()
• vsnprintf_s()
• vsprintf()
• vsprintf_s()
• vsscanf()
• vsscanf_s()
• vswprintf()
• vswprintf_s()
• vswscanf()
• vswscanf_s()
• vwprintf_s()
• vwscanf()
• vwscanf_s()
• wcrtomb()
• wcschr()
• wcsftime()
• wcspbrk()
• wcsrchr()
• wcsrtombs()
• wcsrtombs_s()
• wcsstr()
• wcstod()
• wcstof()
• wcstoimax()
• wcstok()
• wcstok_s()
• wcstol()
• wcstold()
• wcstoll()
• wcstombs()
• wcstombs_s()
• wcstoumax()
• wcstoul()
• wcstoull()
• wcsxfrm()
• wctob()
• wctrans()
• wctype()
• wmemchr()
• wprintf_s()
• wscanf()
• wscanf_s()

This check is an alias of check bugprone-unused-return-value with a fixed set of functions.

The check corresponds to a part of CERT C Coding Standard rule ERR33-C. Detect and handle standard library errors. The list of checked functions is taken from the rule, with following exception:

• The check can not differentiate if a function is called with NULL argument. Therefore the following functions are not checked: mblen, mbrlen, mbrtowc, mbtowc, wctomb, wctomb_s