NAME

media_findname − convert a supplied name into an absolute pathname that can be used to access removable media

SYNOPSIS

cc [ flag... ] file... −lvolmgt [ library.... ]

#include <volmgt.h>

char ∗media_findname(char ∗start);

DESCRIPTION

media_findname() converts the supplied start string into an absolute pathname that can then be used to access a particular piece of media. 

The start parameter can be one of the following types of specifications:

/dev/... An absolute pathname in /dev, such as /dev/rdiskette0, in which case a copy of that string is returned (see NOTES on this page). 

/vol/... An absolute Volume Management pathname, such as /vol/dev/aliases/floppy0 or /vol/dsk/fred.  If this supplied pathname is not a symbolic link, then a copy of that pathname is returned. If the supplied pathname is a symbolic link then it is dereferenced and a copy of that dereferenced pathname is returned. 

volume_name The Volume Management volume name for a particular volume, such as fred (see fdformat(1) for a description of how to label floppies).  In this case a pathname in the Volume Management namespace is returned. 

volmgt_symname The Volume Management symbolic name for a device, such as floppy0 or cdrom2 (see volfs(7FS) for more information on Volume Management symbolic names), in which case a pathname in the Volume Management namespace is returned. 

media_type The Volume Management generic media type name.  For example, floppy or cdrom.  In this case media_findname() looks for the first piece of media that matches that media type, starting at 0 (zero) and continuing on until a match is found (or some fairly large maximum number is reached).  In this case, if a match is found, a copy of the pathname to the volume found is returned. 

RETURN VALUES

Upon successful completion media_findname() returns a pointer to the pathname found.  In the case of an error a null pointer is returned. 

ERRORS

For cases where the supplied start parameter is an absolute pathname, media_findname() can fail, returning a null string pointer, if an lstat(2) of that supplied pathname fails.  Also, if the supplied absolute pathname is a symbolic link, media_findname() can fail if a readlink(2) of that symbolic link fails, or if a stat(2) of the pathname pointed to by that symbolic link fails, or if any of the following is true:

ENXIO The specified absolute pathname was not a character special device, and it was not a directory with a character special device in it. 

EXAMPLES

The following example attempts to find what the Volume Management pathname is to a piece of media called fred.  Notice that a volmgt_check() is done first (see the NOTES section on this page). 

(void) volmgt_check(NULL);
if ((nm = media_findname("fred")) != NULL) {
        (void) printf("media named \"fred\" is at \"%s\"\n", nm);
} else {
  (void) printf("media named \"fred\" not found\n");
}

This example looks for whatever volume is in the first floppy drive, letting media_findname() call volmgt_check() if and only if no floppy is currently known to be the first floppy drive. 

if ((nm = media_findname("floppy0")) != NULL) {
        (void) printf("path to floppy0 is \"%s\"\n", nm);
} else {
        (void) printf("nothing in floppy0\n");
}

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

SEE ALSO

cc(1B), fdformat(1), vold(1M), lstat(2), readlink(2), stat(2), free(3C), malloc(3C), volmgt_check(3X), volmgt_inuse(3X), volmgt_root(3X), volmgt_running(3X), volmgt_symname(3X), attributes(5), volfs(7FS)

NOTES

If media_findname() cannot find a match for the supplied name, it performs a volmgt_check(3X) and tries again, so it can be more efficient to perform volmgt_check() before calling media_findname(). 

Upon success media_findname() returns a pointer to string which has been allocated; this should be freed when no longer in use (see free(3C)). 

SunOS 5.6  —  Last change: 31 Dec 1996