.\" Copyright (c) 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" the American National Standards Committee X3, on Information .\" Processing Systems. .\" .\" %sccs.include.redist.man% .\" .\" @(#)isupper.3 5.5 (Berkeley) 01/08/92 .\" .Dd .Dt ISUPPER 3 .Os .Sh NAME .Nm isupper .Nd upper-case character test .Sh SYNOPSIS .Fd #include .Ft int .Fn isupper "int c"; .Sh DESCRIPTION The .Fn isupper function tests for any upper-case letter. In the ASCII character set, this includes the following characters: .sp .Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ .It \&101\ ``A'' \t102\ ``B'' \t103\ ``C'' \t104\ ``D'' \t105\ ``E'' .It \&106\ ``F'' \t107\ ``G'' \t110\ ``H'' \t111\ ``I'' \t112\ ``J'' .It \&113\ ``K'' \t114\ ``L'' \t115\ ``M'' \t116\ ``N'' \t117\ ``O'' .It \&120\ ``P'' \t121\ ``Q'' \t122\ ``R'' \t123\ ``S'' \t124\ ``T'' .It \&125\ ``U'' \t126\ ``V'' \t127\ ``W'' \t130\ ``X'' \t131\ ``Y'' .It \&132\ ``Z'' .El .Sh RETURN VALUES The .Fn isupper function returns zero if the character tests false and returns non-zero if the character tests true. .Sh SEE ALSO .Xr ctype 3 , .Xr ascii 7 .Sh STANDARDS The .Xr isupper function conforms to .St -ansiC .