1.\" Copyright (c) 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)isdigit.3 5.1 (Berkeley) 05/02/91 7.\" 8.Dd 9.Dt ISDIGIT 3 10.Os 11.Sh NAME 12.Nm isdigit 13.Nd decimal-digit character test 14.Sh SYNOPSIS 15.Fd #include <ctype.h> 16.Ft int 17.Fn isdigit "int c" 18.Sh DESCRIPTION 19The 20.Fn isdigit 21function tests for any decimal-digit character. 22.Sh RETURN VALUES 23The 24.Fn isdigit 25macro returns zero if the character tests false and 26returns non-zero if the character tests true. 27.Sh SEE ALSO 28.Xr isascii 3 , 29.Xr isalnum 3 , 30.Xr isalpha 3 , 31.Xr iscntrl 3 , 32.Xr isdigit 3 , 33.Xr isgraph 3 , 34.Xr islower 3 , 35.Xr isprint 3 , 36.Xr ispunct 3 , 37.Xr isspace 3 , 38.Xr isupper 3 , 39.Xr isxdigit 3 , 40.Xr toascii 3 , 41.Xr tolower 3 , 42.Xr toupper 3 , 43.Xr stdio 3 44.Xr ascii 7 45.Sh STANDARDS 46The 47.Fn isdigit 48function conforms to 49.St -ansiC . 50