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fdevname(3) [freebsd man page]

DEVNAME(3)						   BSD 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 ", devname(buf.st_rdev, S_IFCHR)); printf("fdevname is /dev/%s ", fdevname(fd)); SEE ALSO
stat(2) HISTORY
The devname() function appeared in 4.4BSD. The fdevname() function appeared in FreeBSD 8.0. BSD
February 22, 2005 BSD

Check Out this Related Man Page

GETDEVMAJOR(3)						   BSD Library Functions Manual 					    GETDEVMAJOR(3)

NAME
getdevmajor -- get block or character device major number LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <stdlib.h> #include <sys/stat.h> devmajor_t getdevmajor(const char *name, mode_t type); DESCRIPTION
The getdevmajor() function returns the major device number of the block or character device specified by name and a file type matching the one encoded in type which must be one of S_IFBLK or S_IFCHR. RETURN VALUES
If no device matches the specified values, no information is available, or an error occurs, NODEVMAJOR is returned and errno is set to indi- cate the error. EXAMPLES
To retrieve the major number for pty(4) slave devices (aka pts devices): #include <stdlib.h> #include <sys/stat.h> devmajor_t pts; pts = getdevmajor("pts", S_IFCHR); To retrieve the major numbers for the block and character wd(4) devices: #include <stdlib.h> #include <sys/stat.h> devmajor_t c, b; c = getdevmajor("wd", S_IFCHR); b = getdevmajor("wd", S_IFBLK); ERRORS
The getdevmajor() function may fail and set errno for any of the errors specified for the library functions malloc(3) and sysctlbyname(3). In addition, the following errors may be reported: [EINVAL] The value of the type argument is not S_IFCHR or S_IFBLK. [ENOENT] The named device is not found. SEE ALSO
stat(2), devname(3), malloc(3), sysctlbyname(3) HISTORY
The getdevmajor() function call appeared in NetBSD 3.0. BSD
January 20, 2009 BSD

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