System Services, $DEVICE SCAN, Arguments
*Conan The Librarian
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 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.