| [17270] | 1 | * ABOUT BUGS |
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| 2 | |
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| 3 | Before reporting a bug, please check the list of known bugs |
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| 4 | and the list of oft-reported non-bugs (below). |
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| 5 | |
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| 6 | Bugs and comments may be sent to bug-gnu-utils@gnu.org; please |
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| 7 | include the word ``sed'' in the Subject: header. |
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| 8 | |
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| 9 | Please do not send a bug report like this: |
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| 10 | |
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| 11 | [while building frobme-1.3.4] |
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| 12 | $ configure |
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| 13 | sed: file sedscr line 1: Unknown option to 's' |
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| 14 | $ sed --version |
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| 15 | GNU sed version 3.01 |
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| 16 | |
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| 17 | If GNU sed doesn't configure your favorite package, take a few extra |
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| 18 | minutes to identify the specific problem and make a stand-alone test |
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| 19 | case. |
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| 20 | |
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| 21 | A stand-alone test case includes all the data necessary to perform the |
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| 22 | test, and the specific invocation of sed that causes the problem. The |
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| 23 | smaller a stand-alone test case is, the better. A test case should |
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| 24 | not involve something as far removed from sed as ``try to configure |
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| 25 | frobme-1.3.2''. Yes, that is in principle enough information to look |
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| 26 | for the bug, but that is not a very practical prospect. |
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| 27 | |
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| 28 | |
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| 29 | |
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| 30 | * KNOWN BUGS |
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| 31 | |
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| 32 | Regular expression evaluation performance sucks. Fixing this is |
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| 33 | a high priority for the next release, but I did not want to open |
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| 34 | this can of worms for the 3.01 release because there were more |
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| 35 | important functional bugs which had been wanting fixing. And |
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| 36 | another issue is that the regular expression routines provided |
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| 37 | do not _fully_ support POSIX.2 BREs. |
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| 38 | |
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| 39 | Improvement of the documentation and the testsuite are also in the |
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| 40 | plans for 3.02. Specific suggestions are welcome, but I am |
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| 41 | already aware of the general complaint of "this ain't good |
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| 42 | enough", so you don't need to tell me that. |
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| 43 | |
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| 44 | |
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| 45 | * NON-BUGS |
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| 46 | |
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| 47 | `sed -n' and `s/regex/replace/p' |
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| 48 | |
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| 49 | Some versions of sed ignore the `p' (print) option of an `s' command |
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| 50 | unless the `-n' command switch has been specified. Other versions |
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| 51 | always honor the `p' option. GNU sed is the latter sort. (Both |
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| 52 | approaches are allowed by POSIX.2.) |
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| 53 | |
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| 54 | |
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| 55 | regexp syntax clashes |
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| 56 | |
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| 57 | GNU sed uses the Posix basic regular expression syntax. According to |
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| 58 | the standard, the meaning of some escape sequences is undefined in |
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| 59 | this syntax; notable in the case of GNU sed are `\|', `\+', `\?', |
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| 60 | `\`', `\'', `\<', `\>', `\b', `\B', `\w', and `\W'. |
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| 61 | |
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| 62 | As in all GNU programs that use Posix basic regular expressions, sed |
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| 63 | interprets these escape sequences as meta-characters. So, `x\+' |
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| 64 | matches one or more occurrences of `x'. `abc\|def' matches either |
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| 65 | `abc' or `def'. |
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| 66 | |
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| 67 | This syntax may cause problems when running scripts written for other |
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| 68 | seds. Some sed programs have been written with the assumption that |
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| 69 | `\|' and `\+' match the literal characters `|' and `+'. Such scripts |
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| 70 | must be modified by removing the spurious backslashes if they are to |
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| 71 | be used with GNU sed. |
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