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man pages section 3: Extended Library Functions, Volume 4

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Updated: Thursday, June 13, 2019
 
 

media_findname(3VOLMGT)

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

This function is obsolete. The management of removable media by the Volume Management feature, including vold, has been replaced by software that supports the Hardware Abstraction Layer (HAL). Programmatic support for HAL is through the HAL APIs, which are documented on the HAL web site. See hal(7). The return value of this function is undefined.

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, in which case a copy of that string is returned (see NOTES on this page).

volume_name

The volume name for a particular volume, such as fred.

volmgt_symname

The symbolic name for a device, such as cdrom2.

media_type

The generic media type name, such as 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

The return from this function is undefined.

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

Example 1 Sample programs of the media_findname() function.

The following example attempts to find what the 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");
}

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
MT-Level
MT-Unsafe
Interface Stability
Obsolete

See Also

lstat(2), readlink(2), stat(2), free(3C), malloc(3C), volmgt_check(3VOLMGT), volmgt_inuse(3VOLMGT), volmgt_root(3VOLMGT), volmgt_running(3VOLMGT), volmgt_symname(3VOLMGT), attributes(7), hal(7)

Notes

If media_findname() cannot find a match for the supplied name, it performs a volmgt_check(3VOLMGT) 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)).