View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000942 | 1003.1(2013)/Issue7+TC1 | Shell and Utilities | public | 2015-04-28 21:49 | 2020-10-02 10:47 |
| Reporter | stephane | Assigned To | |||
| Priority | normal | Severity | Editorial | Type | Error |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Stephane Chazelas | ||||
| Organization | |||||
| User Reference | |||||
| Section | expr | ||||
| Page Number | 2740-2741 | ||||
| Line Number | 89697,89702,89724,89737 | ||||
| Interp Status | --- | ||||
| Final Accepted Text | 0000942:0002709 | ||||
| Summary | 0000942: Several problems in "expr" examples | ||||
| Description | 1. > The following works reliably: > > expr X$a = X= That won't work reliably if $a contains characters present in $IFS or wildcard characters. Also X$a == X= doesn't necessarily imply $a == = if there are collation elements that start with X in the locale. 2. > a=$(expr $a + 1) Missing quotes again 3. > expr "$VAR" : '.*' Fails for values of $VAR that are expr operators. | ||||
| Desired Action | 1. Quote the variable in both examples: expr "$a" = = exec "X$a" = X= 2. a=$(expr "$a" + 1) 3. expr '(' "X$VAR" : '.*' ')' - 1 | ||||
| Tags | tc2-2008 | ||||
| related to | 0001407 | Applied | Online Pubs | HTML edition has expr table in reversed order |
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For example 2, if it is known that $a is numeric (which is assumed to be the case, since we are assigning the incremented value back to a), then there are no IFS characters or wildcards that need protection (modulo a very-unlikely setting of IFS that includes digits). Still, I agree that teaching people to be consistent with quoting is easier than explaining which situations do not require quoting. |
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At line 89637 (p 2739, Extended Description), change "increasing precedence" to "decreasing precedence", then rearrange the lines into the following order (still with each group of lines forming a row of the table): line 89640 (table header) line 89668-89760 (integer, string) line 89665-89667 (parentheses) line 89664 (:) line 98659-89663 (*, /, %) line 89657-89658 (+, -) line 89646-89656 (=, >, >=, <, <=, !=) line 89644-89645 (&) line 89641-89643 (|) Move lines 89710-89722 to start of Application Usage (before line 89695). Change line 89697 (page 2740) to: expr "$a" = ’=’ Change line 89702 (page 2740) to: expr "X$a" = X= Change line 89724 (page 2741) to: a=$(expr "$a" + 1) Change line 89737 to: expr "X$VAR" : '.*' - 1 |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2015-04-28 21:49 | stephane | New Issue | |
| 2015-04-28 21:49 | stephane | Name | => Stephane Chazelas |
| 2015-04-28 21:49 | stephane | Section | => http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 |
| 2015-04-28 21:49 | stephane | Page Number | => http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 |
| 2015-04-28 21:49 | stephane | Line Number | => http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 |
| 2015-04-28 21:59 | eblake | Note Added: 0002640 | |
| 2015-06-11 16:13 | geoffclare | Note Added: 0002709 | |
| 2015-06-11 16:15 | geoffclare | Section | http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 => expr |
| 2015-06-11 16:15 | geoffclare | Page Number | http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 => 2740-2741 |
| 2015-06-11 16:15 | geoffclare | Line Number | http://pubs.opengroup.org/onlinepubs/9699919799/utilities/expr.html#tag_20_42_16 => 89697,89702,89724,89737 |
| 2015-06-11 16:15 | geoffclare | Interp Status | => --- |
| 2015-06-11 16:15 | geoffclare | Final Accepted Text | => 0000942:0002709 |
| 2015-06-11 16:15 | geoffclare | Status | New => Resolved |
| 2015-06-11 16:15 | geoffclare | Resolution | Open => Accepted As Marked |
| 2015-06-11 16:15 | geoffclare | Tag Attached: tc2-2008 | |
| 2019-06-10 08:54 | agadmin | Status | Resolved => Closed |
| 2020-10-02 10:47 | geoffclare | Relationship added | related to 0001407 |
