1.\" Copyright (c) 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)islower.3 5.1 (Berkeley) 05/02/91 7.\" 8.Dd 9.Dt ISLOWER 3 10.Os 11.Sh NAME 12.Nm islower 13.Nd lower-case character test 14.Sh SYNOPSIS 15.Fd #include <ctype.h> 16.Ft int 17.Fn islower "int c" 18.Sh DESCRIPTION 19The 20.Fn islower 21function tests for any lower-case letter 22.\" or any of an 23.\" implementation-defined set of characters 24for which none of 25.Xr iscntrl 3 , 26.Xr isdigit 3 , 27.Xr ispunct 3 , 28or 29.Xr isspace 3 30is true. 31In the 32.Em ``C'' 33locale, 34.Fn islower 35returns true only for the characters defined as lower-case letters. 36.Sh RETURN VALUES 37The 38.Fn islower 39macro returns zero if the character tests false and 40returns non-zero if the character tests true. 41.Sh SEE ALSO 42.Xr isascii 3 , 43.Xr isalnum 3 , 44.Xr isalpha 3 , 45.Xr iscntrl 3 , 46.Xr isdigit 3 , 47.Xr isgraph 3 , 48.Xr isprint 3 , 49.Xr ispunct 3 , 50.Xr isspace 3 , 51.Xr isupper 3 , 52.Xr isxdigit 3 , 53.Xr toascii 3 , 54.Xr tolower 3 , 55.Xr toupper 3 , 56.Xr stdio 3 57.Xr ascii 7 58.Sh STANDARDS 59The 60.Fn islower 61function conforms to 62.St -ansiC . 63