media_getattr(3volmgt)

1media_getattr(3VOLMGT)Volume Management Library Functionsmedia_getattr(3VOLMGT)
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NAME

6       media_getattr, media_setattr - get and set media attributes
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SYNOPSIS

9       cc [ flag ... ] file ... -lvolmgt [ library ... ]
10       #include <volmgt.h>
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14       char *media_getattr(char *vol_path, char *attr);
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17       int media_setattr(char *vol_path, char *attr, char *value);
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DESCRIPTION

21       This  function  is  obsolete.  The management of removable media by the
22       Volume Management feature, including vold, has been replaced  by  soft‐
23       ware  that  supports the Hardware Abstraction Layer (HAL). Programmatic
24       support for HAL is through the HAL APIs, which are  documented  on  the
25       HAL  web  site.  See hal(5). The return value of this function is unde‐
26       fined.
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29       media_setattr() and media_getattr() respectively set and get attribute-
30       value pairs (called properties) on a per-volume basis.
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33       Volume  management supports system properties and user properties. Sys‐
34       tem properties are ones that  volume  management  predefines.  Some  of
35       these  system  properties  are writable, but only by the user that owns
36       the volume being specified, and some system properties are read only:
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41        Attribute     Writable                   Value                               Description
42       ──────────────────────────────────────────────────────────────────────────────────────────────────────
43       s-access       RO         "seq", "rand"                           sequential or random access
44       s-density      RO         "low", "medium", "high"                 media density
45       s-parts        RO         comma separated list of slice numbers    list of partitions on this volume
46       s-location     RO         pathname                                volume management pathname to media
47       s-mejectable   RO         "true", "false"                         whether or not  media  is  manually
48                                                                         ejectable
49       s-rmoneject    R/W        "true", "false"                         should   media   access  points  be
50                                                                         removed from database upon ejection
51       s-enxio        R/W        "true", "false"                         if  set  return  ENXIO  when  media
52                                                                         access attempted
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56       Properties  can also be defined by the user. In this case the value can
57       be any string the user wishes.
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RETURN VALUES

60       The return from this function is undefined.
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ERRORS

63       Both media_getattr() and media_setattr()  can  fail  returning  a  null
64       pointer  if  an open(2) of the specified vol_path fails, if an fstat(2)
65       of that pathname fails, or if that pathname is not a block or character
66       special device.
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69       media_getattr() can also fail if the specified attribute was not found,
70       and media_setattr() can also fail if the caller doesn't have permission
71       to  set  the  attribute,  either because it's is a system attribute, or
72       because the caller doesn't own the specified volume.
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EXAMPLES

75       Example 1 Using media_getattr()
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78       The following example checks to see if the volume called fred that vol‐
79       ume  management  is managing can be ejected by means of software, or if
80       it can only be manually ejected:
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83         if (media_getattr("/rdsk/fred", "s-mejectable") != NULL) {
84                 (void) printf("\"fred\" must be manually ejected\n");
85         } else {
86                 (void) printf("software can eject \"fred\"\n");
87         }
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91       This example shows setting the s-enxio property for the  floppy  volume
92       currently in the first floppy drive:
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95         int     res;
96         if ((res = media_setattr("/dev/aliases/floppy0", "s-enxio",
97             "true")) == 0) {
98                 (void) printf("can't set s-enxio flag for floppy0\n");
99         }
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ATTRIBUTES

103       See attributes(5) for descriptions of the following attributes:
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108       ┌─────────────────────────────┬─────────────────────────────┐
109       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
110       ├─────────────────────────────┼─────────────────────────────┤
111       │MT-Level                     │MT-Safe                      │
112       ├─────────────────────────────┼─────────────────────────────┤
113       │Interface Stability          │Obsolete                     │
114       └─────────────────────────────┴─────────────────────────────┘
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