транслитерировать символы верхнего регистра в нижний регистр (transliterate uppercase characters to lowercase)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
tolower, tolower_l — transliterate uppercase characters to
lowercase
Синопсис (Synopsis)
#include <ctype.h>
int tolower(int c);
int tolower_l(int c, locale_t locale);
Описание (Description)
For tolower(): The functionality described on this reference page
is aligned with the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is
unintentional. This volume of POSIX.1‐2017 defers to the ISO C
standard.
The tolower() and tolower_l() functions have as a domain a type
int, the value of which is representable as an unsigned char or
the value of EOF. If the argument has any other value, the
behavior is undefined. If the argument of tolower() or
tolower_l() represents an uppercase letter, and there exists a
corresponding lowercase letter as defined by character type
information in the current locale or in the locale represented by
locale, respectively (category LC_CTYPE), the result shall be the
corresponding lowercase letter. All other arguments in the domain
are returned unchanged.
The behavior is undefined if the locale argument to tolower_l()
is the special locale object LC_GLOBAL_LOCALE or is not a valid
locale object handle.
Возвращаемое значение (Return value)
Upon successful completion, the tolower() and tolower_l()
functions shall return the lowercase letter corresponding to the
argument passed; otherwise, they shall return the argument
unchanged.
Ошибки (Error)
No errors are defined.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
setlocale(3p), uselocale(3p)
The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale,
ctype.h(0p), locale.h(0p)
