Libc-391.5.21.tar.gz

[apple/libc.git] / gen / devname.3

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.\"     @(#)devname.3	8.2 (Berkeley) 4/29/95
.\" $FreeBSD: src/lib/libc/gen/devname.3,v 1.11 2001/10/01 16:08:50 ru Exp $
.\"
.Dd October 25, 2004
.Dt DEVNAME 3
.Os
.Sh NAME
.Nm devname
.Nd get device name
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/stat.h
.In stdlib.h
.Ft char *
.Fn devname "dev_t dev" "mode_t type"
.Ft char *
.Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len"
.Sh DESCRIPTION
The
.Fn devname
function returns a pointer to the name of the block or character
device in
.Dq Pa /dev
with a device number of
.Fa dev ,
and a file type matching the one encoded in
.Fa type
which must be one of
.Dv S_IFBLK
or
.Dv S_IFCHR .
If no device matches the specified values, or no information is
available, NULL is returned.
.Pp
The
.Fn devname
function uses a static buffer, which will be overwritten
on subsequent calls.
The
.Fn devname_r
functions takes a buffer and length as arguments to avoid this problem.
.Pp
The traditional display for applications when no device is
found is the string
.Dq ?? .
.Sh SEE ALSO
.Xr stat 2 ,
.Xr dev_mkdb 8
.Sh HISTORY
The
.Fn devname
function call appeared in
.Bx 4.4 .