asctime | Deprecated in POSIX.1-2008 | Not thread-safe. | strftime or asctime_s |
asctime_r | Deprecated in POSIX.1-2008 | Implementation based on unsafe
function sprintf . | strftime or asctime_s |
bcmp | Deprecated in 4.3BSD Marked as legacy in
POSIX.1-2001. | Returns from function after finding the first differing byte,
making it vulnerable to timing attacks. | memcmp |
bcopy | Deprecated in 4.3BSD Marked as legacy in
POSIX.1-2001. | Returns from function after finding the first differing byte,
making it vulnerable to timing attacks. | memcpy or memmove |
brk and sbrk | Marked as legacy in SUSv2 and POSIX.1-2001. | | malloc |
bsd_signal | Removed in POSIX.1-2008 | | sigaction |
bzero | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008. | | memset |
ctime | Deprecated in POSIX.1-2008 | Not thread-safe. | strftime or asctime_s |
ctime_r | Deprecated in POSIX.1-2008 | Implementation based on unsafe
function sprintf . | strftime or asctime_s |
cuserid | Removed in POSIX.1-2001. | Not reentrant. Precise functionality not standardized causing
portability issues. | getpwuid |
ecvt and fcvt | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008 | Not reentrant | snprintf |
ecvt_r and fcvt_r | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008 | | snprintf |
ftime | Removed in POSIX.1-2008 | | time , gettimeofday , clock_gettime |
gamma , gammaf , gammal | Function not specified in any
standard because of historical variations | Portability issues. | tgamma , lgamma |
gcvt | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008. | | snprintf |
getcontext | Removed in POSIX.1-2008. | Portability issues. | Use POSIX thread instead. |
getdtablesize | BSD API function not included in POSIX.1-2001 | Portability issues. | sysconf( _SC_OPEN_MAX ) |
gethostbyaddr | Removed in POSIX.1-2008 | Not reentrant | getaddrinfo |
gethostbyname | Removed in POSIX.1-2008 | Not reentrant | getnameinfo |
getpagesize | BSD API function not included in POSIX.1-2001 | Portability issues. | sysconf( _SC_PAGESIZE ) |
getpass | Removed in POSIX.1-2001. | Not reentrant. | getpwuid |
getw | Not present in POSIX.1-2001. | | fread |
getwd | Marked legacy in POSIX.1-2001. Removed in POSIX.1-2008. | | getcwd |
index | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008. | | strchr |
makecontext | Removed in POSIX.1-2008. | Portability issues. | Use POSIX thread instead. |
memalign | Appears in SunOS 4.1.3. Not in 4.4 BSD or POSIX.1-2001 | | posix_memalign |
mktemp | Removed in POSIX.1-2008. | Generated names are predictable and can cause a race condition. | mkstemp removes race risk |
pthread_attr_getstackaddr and pthread_attr_setstackaddr | | Ambiguities in the specification of the stackaddr attribute
cause portability issues | pthread_attr_getstack and pthread_attr_setstack |
putw | Not present in POSIX.1-2001. | Portability issues. | fwrite |
qecvt and qfcvt | Marked as legacy in POSIX.1-2001, removed in POSIX.1-2008 | | snprintf |
qecvt_r and qfcvt_r | Marked as legacy in POSIX.1-2001, removed in POSIX.1-2008 | | snprintf |
rand_r | Marked as obsolete in POSIX.1-2008 | | |
re_comp | BSD API function | Portability issues | regcomp |
re_exes | BSD API function | Portability issues | regexec |
rindex | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008. | | strrchr |
scalb | Removed in POSIX.1-2008 | | scalbln , scalblnf , or scalblnl |
sigblock | 4.3BSD signal API whose origin is unclear | | sigprocmask |
sigmask | 4.3BSD signal API whose origin is unclear | | sigprocmask |
sigsetmask | 4.3BSD signal API whose origin is unclear | | sigprocmask |
sigstack | Interface is obsolete and not implemented on most platforms. | Portability issues. | sigaltstack |
sigvec | 4.3BSD signal API whose origin is unclear | | sigaction |
swapcontext | Removed in POSIX.1-2008 | Portability issues. | Use POSIX threads. |
tmpnam and tmpnam_r | Marked as obsolete in POSIX.1-2008. | This function generates a different string each time it is
called, up to TMP_MAX times. If it is called more than TMP_MAX times,
the behavior is implementation-defined. | mkstemp , tmpfile |
ttyslot | Removed in POSIX.1-2001. | | |
ualarm | Marked as legacy in POSIX.1-2001. Removed in POSIX.1-2008. | Errors are under-specified | setitimer or POSIX timer_create |
usleep | Removed in POSIX.1-2008. | | nanosleep |
utime | SVr4, POSIX.1-2001. POSIX.1-2008 marks as obsolete. | | |
valloc | Marked as obsolete in 4.3BSD. Marked as
legacy in SUSv2. Removed from POSIX.1-2001 | | posix_memalign |
vfork | Removed from POSIX.1-2008 | Under-specified in previous standards. | fork |
wcswcs | This function was not included in the final ISO/IEC 9899:1990/Amendment
1:1995 (E). | | wcsstr |
WinExec | WinAPI provides this function only for 16-bit Windows compatibility. | | CreateProcess |
LoadModule | WinAPI provides this function only for 16-bit Windows compatibility. | | CreateProcess |