The following functions in the C library are re-entrant:


     abs          atoi         atol         bsearch
     div          fabs         _fmemccpy    _fmemchr
     _fmemcmp     _fmemcpy     _fmemicmp    _fmemmove
     _fmemset     _fstrcat     _fstrchr     _fstrcmp
     _fstrcpy     _fstrcspn    _fstricmp    _fstrlen
     _fstrlwr     _fstrncat    _fstrncmp    _fstrncpy
     _fstrnicmp   _fstrnset    _fstrpbrk    _fstrrchr
     _fstrrev     _fstrset     _fstrspn     _fstrstr
     _fstrupr     isalnum      isalpha      isascii
     iscntrl      isdigit      isgraph      islower
     isprint      ispunct      isspace      isupper
     isxdigit     itoa         labs         ldiv
     lfind        longjmp      _lrotl       _lrotr
     lsearch      ltoa         _makepath    mblen
     mbstowcs     mbtowc       memccpy      memchr
     memcmp       memcpy       memicmp      memmove
     memset       movedata     qsort        _rotl
     _rotr        segread      setjmp       _splitpath
     strcat       strchr       strcmp       strcoll
     strcpy       strcspn      stricmp      strlen
     strlwr       strncat      strncmp      strncpy
     strnicmp     strnset      strpbrk      strrchr
     strrev       strset       strspn       strstr
     strupr       swab         tolower      toupper
     ultoa        utoa         wcstombs     wctomb