View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001137 | 1003.1(2013)/Issue7+TC1 | System Interfaces | public | 2017-04-24 23:08 | 2024-06-11 08:54 |
| Reporter | sebor | Assigned To | ajosey | ||
| Priority | normal | Severity | Objection | Type | Error |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Martin Sebor | ||||
| Organization | |||||
| User Reference | |||||
| Section | fprintf | ||||
| Page Number | 900 | ||||
| Line Number | 30186-30193 | ||||
| Interp Status | --- | ||||
| Final Accepted Text | See 0001137:0004145 | ||||
| Summary | 0001137: problems with numbered and unnumbered conversion specifications | ||||
| Description | On line 30200 POSIX specifies that "Each conversion specification is introduced by the ’%’ character [CX] or by the character sequence "%n$", [CX end] after which the following appear in sequence: ...[optional flags, width, precision, length modifier, and a required conversion specifier]." However, this specification is in apparent contradiction to the text earlier on lines 30186-30187 stating that "The /format/ can contain either numbered argument conversion specifications (that is, "%n$" and "*m$"), or unnumbered argument conversion specifications (that is, % and *), but not both." referring to all of "%n$", "*m$", % and * as conversion specifications. In addition, on line 30224 POSIX further states that "In format strings containing the "%n$" form of a conversion specification, ..." again referring to "%n$" as a form of a conversion specification. I believe the problems are due to the following: First, neither "%" nor "%n$" alone is a complete conversion specification because they are missing the required conversion specifier. Thus the text in the first set of parentheses on lines 30186-30187 isn't entirely correct. Second, neither "*m$" nor "*" is a conversion specification because as shown they are neither introduced by the % character nor followed by a conversion specifier. This makes the text in the second set of parentheses also incorrect. Additionally, on line 30207 POSIX repeats the C requirement that "The field width takes the form of an <asterisk> (’*’), described below, or a decimal integer. and on lines 30213-30215: "The precision takes the form of a <period> (’.’) followed either by an <asterisk> (’*’), described below, or an optional decimal digit string, where a null digit string is treated as zero." effectively excluding the "*m$" form or width and precision, yet seemingly allowing the asterisk and the decimal integer forms in both numbered and unnumbered conversion specifications. But on lines 30223-30225, however, POSIX then goes on to say that "In format strings containing the "%n$" form of a conversion specification, a field width or precision may be indicated by the sequence "*m$" ..." These requirements are both ambiguous and/or contradictory: In format specifications that start with "%n$", is the "*m$" form the only valid for of width and precision, or can they also be specified by a decimal digit string? Also, if precision may be indicated by the sequence "*m$" does it mean that it does not start with the period like the ".*" form does? | ||||
| Desired Action | 1) Replace the sentence on lines 30186-30187 with The /format/ can contain either numbered argument conversion specifications (that is, those introduced by "%n$" and, optionally, containing the "*m$" forms of field width and precision), or unnumbered argument conversion specifications (that is, those introduced by the % character and, optionally containing the * form of field width and precision), but not both. 2) Replace the text on line 30207 with The field width takes the form of an <asterisk> (’*’), [CX] or in conversion specifications introduced by "%n$" the "*m$" string,[CX end] described below, or a decimal integer. 3) Replace the text on lines 30213-30215 with The precision takes the form of a <period> (’.’) followed either by an <asterisk> (’*’), [CX] or in conversion specifications introduced by "%n$" the "*m$" string,[CX end] described below, or an optional decimal digit string, where a null digit string is treated as zero." 4) Replace the text on line 30224 with In format strings containing conversion specifications introduced by "%n$", in addition to being indicated by the decimal digit string, a field width may be indicated by the sequence "*m$" and precision by the sequence ".*m$", where m is a decimal integer ... | ||||
| Tags | tc3-2008 | ||||
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NOTE page and line numbers quoted for the 2013 edition (TC1). Page is 900 (fprintf) and 982 (fwprintf). 1) Change the sentence on lines 30186-30187 from: The format can contain either numbered argument conversion specifications (that is, "%n$" and "*m$"), or unnumbered argument conversion specifications (that is, % and *), but not both. to: The format can contain either numbered argument conversion specifications (that is, those introduced by "%n$" and optionally containing the "*m$" forms of field width and precision), or unnumbered argument conversion specifications (that is, those introduced by the % character and optionally containing the * form of field width and precision), but not both. 2) Change the text on line 30207 from: The field width takes the form of an <asterisk> (’*’), described below, or a decimal integer. to: The field width takes the form of an <asterisk> (’*’), [CX] or in conversion specifications introduced by "%n$" the "*m$" string,[/CX] described below, or a decimal integer. 3) Change the text on lines 30213-30215 from: The precision takes the form of a <period> (’.’) followed either by an <asterisk> (’*’), described below, or an optional decimal digit string, where a null digit string is treated as zero. to: The precision takes the form of a <period> (’.’) followed either by an <asterisk> (’*’), [CX] or in conversion specifications introduced by "%n$" the "*m$" string,[/CX] described below, or an optional decimal digit string, where a null digit string is treated as zero." 4) Change the text on line 30224 from: In format strings containing the "%n$" form of a conversion specification, a field width or precision may be indicated by the sequence "*m$", where m is a decimal integer ... to: In format strings containing conversion specifications introduced by "%n$", in addition to being indicated by the decimal digit string, a field width may be indicated by the sequence "*m$" and precision by the sequence ".*m$", where m is a decimal integer ... 5) Repeat all of the above on the equivalent lines in the fwprintf description (page 982). |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2017-04-24 23:08 | sebor | New Issue | |
| 2017-04-24 23:08 | sebor | Status | New => Under Review |
| 2017-04-24 23:08 | sebor | Assigned To | => ajosey |
| 2017-04-24 23:08 | sebor | Name | => Martin Sebor |
| 2017-04-24 23:08 | sebor | Section | => fprintf |
| 2017-04-24 23:08 | sebor | Page Number | => 982 |
| 2017-04-24 23:08 | sebor | Line Number | => 30186-30193 |
| 2018-10-04 15:47 | geoffclare | Project | 1003.1(2008)/Issue 7 => 1003.1(2013)/Issue7+TC1 |
| 2018-10-04 16:28 | nick | Note Added: 0004145 | |
| 2018-10-04 16:29 | nick | Interp Status | => --- |
| 2018-10-04 16:29 | nick | Final Accepted Text | => See 0001137:0004145 |
| 2018-10-04 16:29 | nick | Status | Under Review => Resolved |
| 2018-10-04 16:29 | nick | Resolution | Open => Accepted As Marked |
| 2018-10-04 16:30 | nick | Tag Attached: tc3-2008 | |
| 2018-10-04 16:31 | nick | Page Number | 982 => 900 |
| 2019-11-05 11:55 | geoffclare | Status | Resolved => Applied |
| 2024-06-11 08:54 | agadmin | Status | Applied => Closed |
