isupper(3)                                                   isupper(3)

  isupper()

  NAME

    isupper() - upper-case character test

  SYNOPSIS

    #include 

    int isupper (int c)

  DESCRIPTION

    The isupper(3) function tests for any upper-case letter.

  RETURN VALUES

    The isupper(3) function tests whether c is a character of class upper in
    the program's current locale.

    In the POSIX locale, the character class upper includes the following
    characters:
    "A"     "B"     "C"     "D"     "E"

    "F"     "G"     "H"     "I"     "J"

    "K"     "L"     "M"     "N"     "O"

    "P"     "Q"     "R"     "S"     "T"

    "U"     "V"     "W"     "X"     "Y"

    "Z"

  SEE ALSO

    isalnum(3)

    isalpha(3)

    isblank(3)

    iscntrl(3)

    isdigit(3)

    isgraph(3)

    islower(3)

    isprint(3)

    ispunct(3)

    isspace(3)

    isxdigit(3)

    tolower(3)

    toupper(3)

  USAGE NOTES

    The isupper function is thread safe.

    The isupper function is not async-signal safe.