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DEVNAME(3)
DEVNAME(3) FreeBSD Library Functions Manual DEVNAME(3)

NAME

devnameget 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.
February 22, 2005 FreeBSD