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DEVNAME(3) FreeBSD Library Functions Manual DEVNAME(3)
NAME
devname - get device name
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/stat.h>
#include <stdlib.h>
char *
devname(dev_t dev, mode_t type);
char *
devname_r(dev_t dev, mode_t type, char *buf, int len);
char *
fdevname(int fd);
char *
fdevname_r(int fd, char *buf, int len);
DESCRIPTION
The devname() function returns a pointer to the name of the block or
character device in /dev with a device number of dev, and a file type
matching the one encoded in type which must be one of S_IFBLK or S_IFCHR.
To find the right name, devname() asks the kernel via the kern.devname
sysctl. If it is unable to come up with a suitable name, it will format
the information encapsulated in dev and type in a human-readable format.
The fdevname() and fdevname_r() function obtains the device name directly
from a file descriptor pointing to a character device. If it is unable
to come up with a suitable name, these functions will return a NULL
pointer.
devname() and fdevname() return the name stored in a static buffer which
will be overwritten on subsequent calls. devname_r() and fdevname_r()
take a buffer and length as argument to avoid this problem.
EXAMPLES
int fd;
struct stat buf;
char *name;
fd = open("/dev/tun");
fstat(fd, &buf);
printf("devname is /dev/%s\n", devname(buf.st_rdev, S_IFCHR));
printf("fdevname is /dev/%s\n", fdevname(fd));
SEE ALSO
stat(2)
HISTORY
The devname() function appeared in 4.4BSD. The fdevname() function
appeared in FreeBSD 8.0.
FreeBSD 14.0-RELEASE-p6 February 22, 2005 FreeBSD 14.0-RELEASE-p6