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Postings from August 2010
It came up on the Git list[1] that perl -pi -e 's///' isn't portable
to Windows for the same reason that sed -i isn't. Windows doesn't
support clobbering.
That leaves the question of what we should do. In 2002 Gerrit P. Haase
thought that should be, on Cygwin[2].
+#if defined(__CYGWIN__) /* do backup extension automagically */
+ if (*(s+1) == '\0') {
+ PL_inplace = savepv(".bak");
+ return s+1;
+ }
+#endif /* __CYGWIN__ */
That code is still sitting in perl.c today, silently turning "perl -pi
-e 's///'" on Cygwin into "perl -pi.bak -e 's///'".
Do we really want to do that? That means that this shellscript will
silently break on Cygwin:
echo foo > f &&
perl -pi -e 's/foo/bar/g' f &&
grep -q bar f
Since perl will have silently created a f.bak with "bar" behind your
back.
Shouldn't we either die loudly saying that Windows doesn't support
clobbering with "perl -pi", or at least do the same thing on Cygwin,
Win32, MINGW etc? It seems nobody raised Unix shellscript
compatibility when this was applied in 2002[3].
What do the sed implementations that have been ported to Windows do?
Other than assume that they're still running on a Unix system, that
is.
1. http://kerneltrap.org/mailarchive/git/2010/8/8/36314/thread#mid-36314
2. http://perl5.git.perl.org/perl.git/commitdiff/c030f24b?hp=4c7fc0a422d59e20b533b9ae25dd19c2ebfb68b6
3. http://www.nntp.perl.org/group/perl.perl5.porters/2002/05/msg60275.html
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