* ABOUT BUGS Before reporting a bug, please check the list of known bugs and the list of oft-reported non-bugs (below). Bugs and comments may be sent to bug-gnu-utils@gnu.org; please include the word ``sed'' in the Subject: header. Please do not send a bug report like this: [while building frobme-1.3.4] $ configure sed: file sedscr line 1: Unknown option to 's' $ sed --version GNU sed version 3.01 If GNU sed doesn't configure your favorite package, take a few extra minutes to identify the specific problem and make a stand-alone test case. A stand-alone test case includes all the data necessary to perform the test, and the specific invocation of sed that causes the problem. The smaller a stand-alone test case is, the better. A test case should not involve something as far removed from sed as ``try to configure frobme-1.3.2''. Yes, that is in principle enough information to look for the bug, but that is not a very practical prospect. * KNOWN BUGS Regular expression evaluation performance sucks. Fixing this is a high priority for the next release, but I did not want to open this can of worms for the 3.01 release because there were more important functional bugs which had been wanting fixing. And another issue is that the regular expression routines provided do not _fully_ support POSIX.2 BREs. Improvement of the documentation and the testsuite are also in the plans for 3.02. Specific suggestions are welcome, but I am already aware of the general complaint of "this ain't good enough", so you don't need to tell me that. * NON-BUGS `sed -n' and `s/regex/replace/p' Some versions of sed ignore the `p' (print) option of an `s' command unless the `-n' command switch has been specified. Other versions always honor the `p' option. GNU sed is the latter sort. (Both approaches are allowed by POSIX.2.) regexp syntax clashes GNU sed uses the Posix basic regular expression syntax. According to the standard, the meaning of some escape sequences is undefined in this syntax; notable in the case of GNU sed are `\|', `\+', `\?', `\`', `\'', `\<', `\>', `\b', `\B', `\w', and `\W'. As in all GNU programs that use Posix basic regular expressions, sed interprets these escape sequences as meta-characters. So, `x\+' matches one or more occurrences of `x'. `abc\|def' matches either `abc' or `def'. This syntax may cause problems when running scripts written for other seds. Some sed programs have been written with the assumption that `\|' and `\+' match the literal characters `|' and `+'. Such scripts must be modified by removing the spurious backslashes if they are to be used with GNU sed.