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\" @(#)devname.3 8.2 (Berkeley) 4/29/95
\"
Dd September 9, 2017
Dt DEVNAME 3
Os
Sh NAME
Nm devname ,
Nm devname_r
Nd get device name
Sh LIBRARY
Lb libc
Sh SYNOPSIS
In stdlib.h
In sys/stat.h
Ft char *
Fn devname "dev_t dev" "mode_t type"
Ft int
Fn devname_r "dev_t dev" "mode_t type" "char *path" "size_t len"
Sh DESCRIPTION
The
Fn devname
function returns a pointer to the static buffer with 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 S_IFBLK or S_IFCHR.
If no device matches the specified values, or no information is
available,
Dv NULL
is returned.
Pp
The
Fn devname_r
function is a reentrant and thread-safe version of
Fn devname .
This function returns the device name by copying it into the
Fa path
argument with up to
Fa len
characters.
The
Fa path
argument is always nul-terminated.
Pp
The traditional display for applications when no device is
found is the string
Dq ?? .
Sh RETURN VALUES
If successful,
Fn devname
returns a pointer to a nul-terminated string containing the name of the device.
If an error occurs
Fa devname
will return
Dv NULL .
Pp
If successful,
Fn devname_r
places a nul-terminated string containing the name of the device in
the buffer pointed to by
Ar path
and returns 0.
If an error occurs
Fn devname_r
will return an error number from
In sys/errno.h
indicating what went wrong.
Sh FILES
Bl -tag -width /var/run/dev.cdb -compact
It Pa /var/run/dev.cdb
Device database file.
El
Sh ERRORS
The
Fn devname_r
function may fail if:
Bl -tag -width Er
It Bq Er ENOENT
The corresponding device does not exist.
It Bq Er ERANGE
The passed buffer length is too short.
El
Sh SEE ALSO
Xr stat 2 ,
Xr dev_mkdb 8
Sh HISTORY
The
Nm devname
function call appeared in
Bx 4.4 .
Pp
The
Fn devname_r
function first appeared in
Nx 6.0 .
