For every library function in the C runtime system that works with characters and/or strings or returns a character or string (e.g. printf), there is:
an implementation of the function for processing characters and/or strings in EBCDIC format
an implementation of the function for processing characters and/or strings in ASCII format
a macro define that maps the original function (EBCDIC format) to the associated ASCII function
The prototype of an ASCII function and the associated define are stored in the include file in which the corresponding original file is declared. This has the advantage that no additional include files are required to use ASCII-encoded characters and strings, with the possible exception of <ascii_ebcdic.h> (see "Explicitly switching between EBCDIC and ASCII encoding").
Names of the ASCII functions
The syntax of the names of the ASCII functions is as follows:
__ originalfunction _ascii()
The name of the original function should be specified for originalfunction.
The ASCII variant of printf(), for example, is __printf_ascii().
C library functions for which there is an ASCII function
There is an ASCII variant for each of the following C library functions:
asctime | assert | atof | atoi | atol |
atoll | bs2cmd | bs2exit | bs2fstat | c16rtomb |
c32rtomb | creat | creat64 | ctime | ctime64 |
ecvt | fdopen | fgetc | fgets | fopen |
fopen64 | fprintf | fputc | fputs | fread |
freopen | freopen64 | fscanf | fwrite | gcvt |
getc | getc_unlocked | getchar | getchar_unlocked | getenv |
getlogin | getpgmname | gets | gettsn | _guuid4 |
isalnum | isalpha | isascii | iscntrl | isdigit |
isgraph | islower | isprint | ispunct | isspace |
isupper | isxdigit | localeconv | mbrtoc16 | mbrtoc32 |
mktemp | open | open64 | perror | printf |
putc | putc_unlocked | putchar | putchar_unlocked | putenv |
puts | remove | rename | scanf | setenv |
setlocale | snprintf | sprintf | sscanf | strcoll |
strerror | strftime | strlower | strptime | strtod |
strtof | strtoimax | strtold | strtol | strtoll |
strtoul | strtoull | strtoumax | strupper | strxfrm |
system | tmpnam | tolower | toupper | ungetc |
unsetenv | vfprintf | vfscanf | vprintf | vscanf |
vsnprintf | vsprintf | vsscanf |