To: J3 J3/19-131r1 From: Malcolm Cohen Subject: Connection of INPUT_UNIT Date: 2019-February-13 ---------------------------------------------------------------------- NUMBER: F18/006 TITLE: Connection of INPUT_UNIT on different images KEYWORDS: Connection, INPUT_UNIT DEFECT TYPE: Erratum STATUS: J3 consideration in progress QUESTION: According to 16.10.2.13 INPUT_UNIT [429:8-9], "The value of the default integer scalar constant INPUT_UNIT identifies the same processor-dependent external unit preconnected for sequential formatted input as the one identified by an asterisk in a READ statement;" and according to 12.5.1 Referring to a file [217:10-11], "In a READ statement, an io-unit that is an asterisk identifies an external unit that is preconnected for sequential formatted input on image 1 in the initial team only (12.6.4.3)." This leaves unanswered the status of the i/o unit identified by INPUT_UNIT on images other that 1. Plausible interpretations are: (a) it is not preconnected on other images; (b) it is preconnected, but to a processor-dependent file; (c) it is preconnected, but it is not standard-conforming for a program to use it; (d) it is preconnected, but it raises an i/o error condition if a program attempts to use it; (e) attempting to use INPUT_UNIT in any way, including connecting it to another file, is not conforming; (f) INPUT_UNIT may be connected to another file, but it is still processor-dependent whether it may be used; (g) on an image other than image 1, - it is processor-dependent whether it is preconnected, - if it is preconnected, * it is processor-dependent to what file, * it is processor-dependent whether use is permitted, - if it is subsequently connected, it is processor-dependent whether it may be used. Q1. What is the preconnection status of INPUT_UNIT on images other than image one? Q2. On an image other than image one, if INPUT_UNIT happens to be preconnected, may it be used? Q3. On an image other than image one, if INPUT_UNIT is connected to a different file by an OPEN statement, may it be used? Also, the definition text for INPUT_UNIT in 16.10.2.13 makes no mention of any caveat, but implies it is preconnected on every image. Perhaps this text could be clarified. ANSWER: A1. INPUT_UNIT (and thus the unit identified by an asterisk in a READ statement) was not intended to be preconnected on images other than image one in the initial team. An edit is supplied to correct this omission. A2. Moot. A3. Yes. EDITS to 18-007r1: [217:11] 12.5.1 Referring to a file, p4, After "on image 1 in the initial team only (12.6.4.3)" insert "; it is not preconnected on any other image". {Clarify preconnection state on images other than one.} {Editor notes that "image 1" should be "image one".} [429:9,10] 16.10.2.13 INPUT_UNIT, p1, Delete "preconnected for sequential formatted input". {This is a mere parenthetical remark which could confuse.} After "input/output control list (12.6.4.3)." insert new sentence "This unit is preconnected for sequential formatted input on image one in the initial team only, and is not preconnected on any other image." {Make this match clause 12.} SUBMITTED BY: Malcolm Cohen HISTORY: 19-131 m218 Submitted 19-131r1 m218 Revised ----------------------------------------------------------------------