conv(3C)                       DG/UX R4.11MU05                      conv(3C)


NAME
       conv: toupper, tolower, _toupper, _tolower, toascii - translate
       characters

SYNOPSIS
       #include <ctype.h>

       int toupper (int c);

       int tolower (int c);

       int _toupper (int c);

       int _tolower (int c);

       int toascii (int c);

DESCRIPTION
       toupper and tolower have as their domain the range of the function
       getc: all values represented in an unsigned char and the value of the
       macro EOF as defined in stdio.h.  If the argument of toupper
       represents a lower-case letter, the result is the corresponding
       upper-case letter.  If the argument of tolower represents an upper-
       case letter, the result is the corresponding lower-case letter.  All
       other arguments in the domain are returned unchanged.

       The macros _toupper and _tolower accomplish the same things as
       toupper and tolower, respectively, but have restricted domains and
       are faster.  _toupper requires a lower-case letter as its argument;
       its result is the corresponding upper-case letter.  _tolower requires
       an upper-case letter as its argument; its result is the corresponding
       lower-case letter.  Arguments outside the domain cause undefined
       results.

       toascii yields its argument with all bits turned off that are not
       part of a standard 7-bit ASCII character; it is intended for
       compatibility with other systems.

       toupper, tolower, _toupper, and_tolower are affected by LC_CTYPE.  In
       the C locale, or in a locale where shift information is not defined,
       these functions determine the case of characters according to the
       rules of the ASCII-coded character set.  Characters outside the ASCII
       range of characters are returned unchanged.

   Considerations for Threads Programming
                     +---------+-----------------------------+
                     |         |                      async- |
                     |function | reentrant   cancel   cancel |
                     |         |             point     safe  |
                     +---------+-----------------------------+
                     |_tolower |     Y         N        N    |
                     |_toupper |     Y         N        N    |
                     |toascii  |     Y         N        N    |
                     |tolower  |     Y         N        N    |
                     |toupper  |     Y         N        N    |
                     +---------+-----------------------------+
       Although these functions are considered to be reentrant, there are
       some limitations on their usage.  For a full explanation, see the
       setlocale(3C) man page.

SEE ALSO
       iconv(1), reentrant(3), ctype(3C), getc(3S), setlocale(3C),
       environ(5).


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