The following functions are compatible with ANSI: clearerr, fclose, feof, ferror, fflush, fgetc, fgetpos, fgets, fopen, fprintf, fputc, fputs, fread, freopen, fscanf, fseek, fsetpos, ftell, fwrite, getc, getchar, gets, perror, printf, putc, putchar, puts, remove, rename, rewind, scanf, setbuf, setvbuf, sprintf, sscanf, tmpfile, tmpnam, vfprintf, ungetc, vprintf, vsprintf, memchr, memcmp, memcpy, memmove, memset, strcat, strchr, strcmp, strcoll, strcpy, strcspn, strerror, strlen, strncat, strncmp, strncpy, strpbrk, strrchr, strspn, strstr, strtok, strxfrm abort, abs, assert, atexit, atof, atoi, atol, bsearch, calloc, div, exit, free, getenv, labs, ldiv, longjmp, malloc, mblen, mbstowcs, mbtowc, qsort, rand, realloc, setjmp, srand, strtod, strtol, strtoul, system, wcstombs, wctomb asctime, gmtime, localtime, time, clock, ctime, difftime, mktime, strftime raise, signal isalnum, isalpha, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace, isupper, isxdigit, tolower, toupper acos, asin, atan, atan2, ceil, cos, cosh, exp, fabs, floor, fmod, frexp, ldexp, log, log10, modf, pow, sin, sinh, sqrt, tan, tanh localeconv, setlocale, va_arg, va_end, va_start