1.\" Copyright (c) 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" %sccs.include.redist.man% 9.\" 10.\" @(#)isupper.3 5.3 (Berkeley) 10/23/91 11.\" 12.Dd 13.Dt ISUPPER 3 14.Os 15.Sh NAME 16.Nm isupper 17.Nd upper-case character test 18.Sh SYNOPSIS 19.Fd #include <ctype.h> 20.Ft int 21.Fn supper "int c"; 22.Sh DESCRIPTION 23The 24.Fn isupper 25function tests for any upper-case letter or any of an 26implementation-defined set of characters for which none of 27.Xr iscntrl 3 , 28.Xr isdigit 3 , 29.Xr ispunct 3 , 30or 31.Xr isspace 3 32is true. 33In the 34.Em ``C'' 35locale, 36.Fn isupper 37returns true only for the characters defined as upper-case letters. 38.Sh RETURN VALUES 39The 40.Fn isupper 41function returns zero if the character tests false and 42returns non-zero if the character tests true. 43.Sh SEE ALSO 44.Xr ctype 3 , 45.Xr ascii 7 46.Sh STANDARDS 47The 48.Xr isupper 49function conforms to 50.St -ansiC . 51