Arguments

 

return_devnam

   OpenVMS usage:char_string
   type:         character-coded text string
   access:       write only
   mechanism:    by descriptor-fixed-length string descriptor
   Buffer to receive the device name. The return_devnam argument is
   the address of a character string descriptor pointing to a buffer
   into which $DEVICE_SCAN writes the name of the first or next
   device that matches the specified search criteria. The maximum
   size of any device name is 64 bytes.
 

retlen

   OpenVMS usage:word_unsigned
   type:         word (unsigned)
   access:       write only
   mechanism:    by reference
   Length of the device name string returned by $DEVICE_SCAN. The
   retlen argument is the address of a word into which $DEVICE_SCAN
   writes the length of the device name string.
 

search_devnam

   OpenVMS usage:device_name
   type:         character-coded text string
   access:       read only
   mechanism:    by descriptor-fixed-length string descriptor
   Name of the device for which $DEVICE_SCAN is to search. The
   search_devnam argument accepts the standard wildcard characters,
   the asterisk (*), which matches any sequence of characters, and
   the percent sign (%), which matches any one character. If the
   search_devnam argument does not include a wildcard character,
   an exact match is used for comparison. For example, to match all
   unit 0 DU devices on any controller, specify *DU%0. This string
   is compared to the most complete device name (DVI$_ALLDEVNAM).
   Only uppercase characters are accepted.
 

itmlst

   OpenVMS usage:item_list_3
   type:         longword_unsigned
   access:       read only
   mechanism:    by reference
   Item list specifying search criteria used to identify the device
   names for return by $DEVICE_SCAN. The itmlst argument is the
   address of a list of item descriptors, each of which describes
   one search criterion. The list of item descriptors is terminated
   by a longword of 0.

   Refer to the VSI OpenVMS System Services Reference Manual to view
   the item code diagram and descriptor fields table.
 

contxt

   OpenVMS usage:quadword_unsigned
   type:         quadword (unsigned)
   access:       modify
   mechanism:    by reference
   Value used to indicate the current position of a $DEVICE_SCAN
   search. The contxt argument is the address of the quadword that
   receives this information. On the initial call, the quadword
   should contain 0.