1.\" Copyright (c) 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.\" %sccs.include.redist.man% 9.\" 10.\" @(#)isdigit.3 8.1 (Berkeley) 06/04/93 11.\" 12.Dd 13.Dt ISDIGIT 3 14.Os 15.Sh NAME 16.Nm isdigit 17.Nd decimal-digit character test 18.Sh SYNOPSIS 19.Fd #include <ctype.h> 20.Ft int 21.Fn isdigit "int c"; 22.Sh DESCRIPTION 23The 24.Fn isdigit 25function tests for any decimal-digit character. 26In the ASCII character set, this includes the following characters: 27.sp 28.Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ 29.It \&060\ ``0'' \t061\ ``1'' \t062\ ``2'' \t063\ ``3'' \t064\ ``4'' 30.It \&065\ ``5'' \t066\ ``6'' \t067\ ``7'' \t070\ ``8'' \t071\ ``9'' 31.El 32.Sh RETURN VALUES 33The 34.Fn isdigit 35function returns zero if the character tests false and 36returns non-zero if the character tests true. 37.Sh SEE ALSO 38.Xr ctype 3 , 39.Xr ascii 7 40.Sh STANDARDS 41The 42.Fn isdigit 43function conforms to 44.St -ansiC . 45