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G.5. Reading the INFOR Table
INFOR Information
The INFOR data is supplied as input data to the first symbiont read operation performed
by the program. The program issues an ER AREAD$, ER READ$, or ER SYMB$
(READ$ function) with a buffer size of at least 27 words specified. The INFOR data is
received in blocks of 27 words or less. Only full subfield descriptions are put in the
block. If a subfield description does not fit within the last words of the block, it is put in
the next block.
Upon return from the read, register A0 contains the following information:
Bit 4 This bit is set if the data transferred into the buffer is INFOR data.
Bit 5 This bit is set if more INFOR data needs to be read.
Bits 18–35 These bits specify the number of words transferred into the buffer.
Notes:
• If the program issues a read command that specifies a buffer size less than 27
words, INFOR data may be transferred into the area beyond the end of the buffer.
• The SYSLIB and the SLIB service libraries provide INFOR routines to read the INFOR
table, to search it, and to transfer data from it to other tables. See the SLIB
Programming Reference Manual.
G.6. Determining the INFOR Table Size
If a program intends to read the entire INFOR table into memory, the size of the memory
area needed to hold the INFOR table can be determined by adding the maximum sizes
needed by the various types of information that are put in the table.
1 Word 0 of INFOR table
+ 18 Words needed for field 1 of the command field if it contains a
fully specified file name and element name.
+ 20*n
————
sum
n is the number of fields that the program expects in the
specification field. Multiply n by 20, which is the number of
words needed by each field if it contains a fully specified file
name and element name.
The sum above is the maximum size of the INFOR table.
7833 1733–004 G–9