Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

Guardian Native C Library Calls (t - z) _tolower(3)
NAME
_tolower - Translates uppercase characters to lowercase characters
LIBRARY
G-series native Guardian processes: $SYSTEM.SYSnn.ZCRTLSRL
G-series native OSS processes: /G/system/sysnn/zcrtlsrl
H-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCRTLDLL
H-series OSS processes: /G/system/zdllnnn/zcrtldll
SYNOPSIS
#include <ctype.h>
int _tolower (
int c);
PARAMETERS
c Specifies the character to be converted.
DESCRIPTION
The _tolower() macro translates all characters, including multibyte characters, to their specified
character values.
The _tolower() macro takes an int value that can be represented as an unsigned char or the
value of EOF (defined in the stdio.h header file) as its input.
When the input of the _tolower() macro expresses an uppercase letter, as defined by character
type information in the program locale (category LC_CTYPE), the corresponding lowercase
letter is returned.
In the C locale, or in a locale where case-conversion information is not defined, the _tolower()
macro determines the case of characters according to the rules of the ASCII-coded character set.
NOTES
The _tolower() macro is equivalent to the tolower() function, but executes faster. If the value of
the c parameter to the _tolower() macro does not have a corresponding lowercase character, the
results of the function are undefined.
The LC_CTYPE category of the setlocale() function affects all conversions. See the setlo-
cale() function for more information.
RETURN VALUES
When the c parameter is a character for which the isupper() function is TRUE, there is a
corresponding character for which the islower() function is also TRUE. That lowercase charac-
ter is returned by the _tolower() macro. Otherwise, the c parameter is returned.
RELATED INFORMATION
Functions: setlocale(3), tolower(3), toupper(3), _toupper(3).
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