1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)digittoint.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd December 19, 2022 32.Dt DIGITTOINT 3 33.Os 34.Sh NAME 35.Nm digittoint , 36.Nm digittoint_l 37.Nd convert a numeric character to its integer value 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In ctype.h 42.Ft int 43.Fn digittoint "int c" 44.Ft int 45.Fn digittoint_l "int c" "locale_t loc" 46.Sh DESCRIPTION 47The 48.Fn digittoint 49and 50.Fn digittoint_l 51functions convert a numeric character to its corresponding integer value. 52The character can be any decimal digit or hexadecimal digit. 53With hexadecimal characters, the case of the values does not matter. 54.Pp 55The 56.Fn digittoint_l 57function takes an explicit locale argument, whereas the 58.Fn digittoint 59function use the current global or per-thread locale. 60.Sh RETURN VALUES 61The 62.Fn digittoint 63and 64.Fn digittoint_l 65functions always return an integer from the range of 0 to 15. 66If the given character was not a digit as defined by 67.Xr isxdigit 3 68or 69.Xr isxdigit_l 3 , 70the function will return 0. 71.Sh SEE ALSO 72.Xr ctype 3 , 73.Xr ctype_l 3 , 74.Xr isdigit 3 , 75.Xr isdigit_l 3 , 76.Xr isxdigit 3 , 77.Xr isxdigit_l 3 , 78.Xr xlocale 3 79