1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. 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.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd December 19, 2022 33.Dt TOUPPER 3 34.Os 35.Sh NAME 36.Nm toupper , 37.Nm toupper_l 38.Nd lower case to upper case letter conversion 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In ctype.h 43.Ft int 44.Fn toupper "int c" 45.Ft int 46.Fn toupper_l "int c" "locale_t loc" 47.Sh DESCRIPTION 48The 49.Fn toupper 50and 51.Fn toupper_l 52functions convert a lower-case letter to the corresponding 53upper-case letter. 54The argument must be representable as an 55.Vt "unsigned char" 56or the value of 57.Dv EOF . 58.Pp 59The 60.Fn toupper_l 61function takes an explicit locale argument, whereas the 62.Fn toupper 63function uses the current global or per-thread locale. 64.Sh RETURN VALUES 65If the argument is a lower-case letter, the 66.Fn toupper 67and 68.Fn toupper_l 69functions return the corresponding upper-case letter if there is 70one; otherwise, the argument is returned unchanged. 71.Sh COMPATIBILITY 72The 73.Bx 4.4 74extension of accepting arguments outside of the range of the 75.Vt "unsigned char" 76type in locales with large character sets is considered obsolete 77and may not be supported in future releases. 78The 79.Fn towupper 80or 81.Fn towupper_l 82function should be used instead. 83.Sh SEE ALSO 84.Xr ctype 3 , 85.Xr ctype_l 3 , 86.Xr isupper 3 , 87.Xr isupper_l 3 , 88.Xr towupper 3 , 89.Xr towupper_l 3 , 90.Xr xlocale 3 91.Sh STANDARDS 92The 93.Fn toupper 94function conforms to 95.St -isoC . 96