Converts an uppercase alphabetic character to its corresponding lowercase alphabetic character.
Files
lib_ascii.h/lib_ascii.c
Prototypes
Arguments
ch
Character to examine.
Returned Value
Lowercase equivalent of c, if character c is an uppercase character;
Character c, otherwise.
Required Configuration
None.
Notes / Warnings
ISO/IEC 9899:TC2, Section 7.4.2.1.(2) states that “tolower() ... converts an uppercase letter to a corresponding lowercase letter”. ISO/IEC 9899:TC2, Section 7.4.2.1.(3) states that “if the argument is a character for which isupper() is true and there are one or more corresponding characters ... for which islower() is true, ... tolower() ... returns one of the corresponding characters; ... otherwise, the argument is returned unchanged”.