The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group
A newer edition of this document exists here

NAME

_toupper - transliterate lowercase characters to uppercase

SYNOPSIS

[OB XSI] [Option Start] #include <ctype.h>

int _toupper(int
c); [Option End]

DESCRIPTION

The _toupper() macro shall be equivalent to toupper() except that the application shall ensure that the argument c is a lowercase letter.

RETURN VALUE

Upon successful completion, _toupper() shall return the uppercase letter corresponding to the argument passed.

ERRORS

No errors are defined.


The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

Applications should use the toupper() function instead of the obsolescent _toupper() function.

RATIONALE

None.

FUTURE DIRECTIONS

The _toupper() function may be removed in a future version.

SEE ALSO

islower, toupper

XBD Locale, <ctype.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

The normative text is updated to avoid use of the term "must" for application requirements.

Issue 7

The _toupper() function is marked obsolescent.

End of informative text.

 

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