freebsd-skq/lib/libc/gen/devname.3
2003-06-20 09:52:27 +00:00

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.\" @(#)devname.3 8.2 (Berkeley) 4/29/95
.\" $FreeBSD$
.\"
.Dd July 18, 1999
.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
.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 .
To find the right name,
.Fn devname
asks the kernel via the
.Va kern.devname
sysctl.
If it is unable to come up with a suitable name,
it will format the information encapsulated in
.Fa dev
and
.Fa type
in a human-readable format.
.Pp
.Fn devname
returns the name stored in a static buffer which will be overwritten
on subsequent calls.
.Fn devname_r
takes a buffer and length as argument to avoid this problem.
.Sh SEE ALSO
.Xr stat 2 ,
.Sh HISTORY
The
.Fn devname
function appeared in
.Bx 4.4 .