View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001136 | 1003.1(2016/18)/Issue7+TC2 | Shell and Utilities | public | 2017-04-19 20:56 | 2024-06-11 09:09 |
| Reporter | stephane | Assigned To | |||
| Priority | normal | Severity | Editorial | Type | Omission |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Stephane Chazelas | ||||
| Organization | |||||
| User Reference | |||||
| Section | awk | ||||
| Page Number | 2488-2489 | ||||
| Line Number | 80013-80018 | ||||
| Interp Status | --- | ||||
| Final Accepted Text | See 0001136:0004143. | ||||
| Summary | 0001136: awk: missing case where a bare array name may be used | ||||
| Description | nitpick. The spec says: Unsubscripted array names can be used in only the following contexts: * A parameter in a function definition or function call * The NAME token following any use of the keyword in as specified in the grammar (see Grammar); if the name used in this context is not an array name, the behavior is undefined It's missing the case of the second argument to split() | ||||
| Desired Action | Below line 80018, add a third list item: * The second parameter to the split() function It may also be worth pointing out in the first point above, that we're speaking of *user-defined* functions only. Since "delete array" is not supported, it may be worth also adding (in some non-normative section) that split("", var) is one way to empty an array (but that it still gives the "array" type to the variable (that one shouldn't do for instance var = "value" after that). | ||||
| Tags | tc3-2008 | ||||
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Another bug (0000544) has already been accepted to note that <tt>split("", array)</tt> can be used to delete all elements of an array and to allow <tt>delete array</tt> to delete all elements in an array in addition to the <tt>delete array[index]</tt> that can be used to delete a single element from an array. I see no reason to believe that the 1st case in the list mentioned in the Description of this bug report does not include the the array name argument passed to the <tt>split()</tt> function nor do I see any reason to believe that functions provided by an <tt>awk</tt> implementation are never allowed to accept an array name as an argument (with <tt>split()</tt> being an obvious counterexample). I do not see why any change suggested in this bug (other than the changes already specified in 0000544 for inclusion in the next revision of the standard) should be implemented. |
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Re: 0001136:0003673 I understand the first item as one may declare and use functions that take array names as arguments (passed as reference). Apart from split(), no other builtin function specified in this standard accept bare arrays in any implementations I've tried (except for busybox awk where variables can be both scalar and array at the same time). Other builtin functions that awk implementations may provide as extension are out of the scope of this spec, and anyway this standard more or less precludes the addition of extra builtin functions as that would break compliance (prevent users from using them as user-defined functions, see how gawk disables all of it's extra functions under POSIXLY_CORRECT) About bug:544, that would mean a 4th item would need to be added here ("delete" would hardly be taken as a "function" as you typically call it without parenthesis). Also, I don't know about tawk where "delete array" apparently comes from but in gawk and busybox awk, the only implementations I know that also support it, the variable remains of array type after "delete variable", might be worth pointing out explicitly as one could assume that the variable is free to use as a scalar once it has been deleted. Last slightly related point, it may be worth clarifying how array parameters may be passed by reference to user-defined functions (and maybe split() as well). For instance, most awk implementations accept myfunction(foo, (myarray)), but not mawk:
$ gawk 'function f(a) {a[1] = 1}; BEGIN{f((a)); print a[1]}'
1
$ nawk 'function f(a) {a[1] = 1}; BEGIN{f((a)); print a[1]}'
1
$ busybox awk 'function f(a) {a[1] = 1}; BEGIN{f((a)); print a[1]}'
1
$ mawk 'function f(a) {a[1] = 1}; BEGIN{f((a)); print a[1]}'
mawk: line 1: type error in arg(1) in call to f
mawk: line 1: illegal reference to variable a
See also f(mybool ? array : other_array) (that one supported by nawk and busybox awk but not gawk nor mawk). |
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Add a new bullet to the list on P2489 after L80018: * An implementation may allow the operand to the delete statement to be an array name Move the paragraph starting on P2499, L80458 to follow P2496, L80325. (This moves the discussion of array parameters from the user defined functions section to the section that applies to all functions.) Add a new paragraph after P2494, L80242: Implementations may also accept the statement: Add a new line to the grammar after P2502, L80593: | Delete NAME /* See footnote 1.*/ with footnote 1 being: A future version of this standard may require the delete statement with an unsubscripted array name to be accepted. This version of the standard allows but does not require support for this syntax. See also 0000544 for changes to be applied in the next revision of this standard. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2017-04-19 20:56 | stephane | New Issue | |
| 2017-04-19 20:56 | stephane | Name | => Stephane Chazelas |
| 2017-04-19 20:56 | stephane | Section | => awk |
| 2017-04-19 20:56 | stephane | Page Number | => 2488-2489 |
| 2017-04-19 20:56 | stephane | Line Number | => 80013-80018 |
| 2017-04-20 03:15 | Don Cragun | Note Added: 0003673 | |
| 2017-04-20 03:16 | Don Cragun | Note Edited: 0003673 | |
| 2017-04-20 03:17 | Don Cragun | Relationship added | related to 0000544 |
| 2017-04-20 06:11 | stephane | Note Added: 0003674 | |
| 2017-04-24 12:08 | stephane | Note Edited: 0003674 | |
| 2018-10-04 15:17 | Don Cragun | Note Added: 0004143 | |
| 2018-10-04 15:19 | Don Cragun | Interp Status | => --- |
| 2018-10-04 15:19 | Don Cragun | Final Accepted Text | => See 0001136:0004143. |
| 2018-10-04 15:19 | Don Cragun | Status | New => Resolved |
| 2018-10-04 15:19 | Don Cragun | Resolution | Open => Accepted As Marked |
| 2018-10-04 15:21 | Don Cragun | Note Edited: 0004143 | |
| 2018-10-04 15:21 | Don Cragun | Tag Attached: tc3-2008 | |
| 2018-10-04 15:22 | Don Cragun | Note Edited: 0004143 | |
| 2018-10-04 15:22 | Don Cragun | Note Edited: 0003674 | |
| 2019-10-31 11:48 | geoffclare | Status | Resolved => Applied |
| 2024-06-11 09:09 | agadmin | Status | Applied => Closed |
