tolower(3)                                                   tolower(3)

  tolower()

  NAME

    tolower(), _tolower() - upper case to lower case letter conversion

  SYNOPSIS

    #include 

    int tolower (int c)
    int _tolower (int c)

  DESCRIPTION

    The tolower(3) function converts an upper-case letter to the corresponding
    lower-case letter. If c is not an upper-case letter, it is not converted.

    The _tolower(3) function does the same, but the argument c must be an
    upper-case letter. This routine is faster but will break with the wrong
    input.

  RETURN VALUES

    If the argument is an upper-case letter, the tolower(3) function returns
    the corresponding lower-case letter if there is one; otherwise the
    argument is returned unchanged.

  SEE ALSO

    isalnum(3)

    isalpha(3)

    isblank(3)

    iscntrl(3)

    isdigit(3)

    isgraph(3)

    islower(3)

    isprint(3)

    ispunct(3)

    isspace(3)

    isupper(3)

    isxdigit(3)

    toupper(3)

  USAGE NOTES

    All these functions are thread safe.

    None of these functions are async-signal safe.