Hi Marcello,
Marcello Cruz wrote on Fri, Jan 22, 2010 at 10:31:18PM -0200:
> I've read the documentation about sed - sed(8), re_format(7) and
> /usr/share/doc/usd/15.sed/ - but I still don't realize how to make
> this command work:
First decide whether you want to use basic or extended regular
expressions. Than stick to that.
> $ s/(^[A_Z]{1})([a-z]+)\.sgml/\1\2\.html/g
That's an *extended* regular expression, note the '+'.
It almost works:
schwa...@rhea $ echo "Abc.sgml\nBcd.sgml" | \
> sed -E 's/(^[A_Z]{1})([a-z]+)\.sgml/\1\2\.html/g'
Abc.html
Bcd.sgml
Fix the "[A_Z]" to read "[A-Z]", and it already works a bit better.
But you can simplify it:
schwa...@rhea $ echo "Abc.sgml\nBcd.sgml" | \
> sed -E 's/^([A-Z].*)\.sgml$/\1.html/'
Abc.html
Bcd.html
* The '{1}' has no effect.
* No need two have two groups of parantheses.
* According to what you say, you want '.*', not '[a-z]+'.
* You probably want to anchor at the end, too ('$').
* No need to escape the '.' in the replacement.
* The /g modifier is pointless with '^' at the beginning.
You see, there are multiple issues.
> As I read I must prefix the '{', '}', '(' and ')' with backslashes.
That would be *basic* regular expressions:
schwa...@rhea $ echo "Abc.sgml\nBcd.sgml" | \
> sed 's/\(^[A-Z]\{1\}\)\([a-z]+\)\.sgml/\1\2\.html/g'
Abc.html
Bcd.html
Or, again, corrected and simplified:
schwa...@rhea $ echo "Abc.sgml\nBcd.sgml" | \
> sed 's/^\([A-Z].*\)\.sgml/\1.html/'
Abc.html
Bcd.html
> Even if I do so, the command does not work.
When reporting problems, please paste the exact commands you are
typing.
[...]
> I think there is some bug with the implementation of sed or the
> "branch" (one or more pieces concatenated - as stated under
> re_format) is not supported with BRE.
[...]
No, i can't see any bug here.
Yours,
Ingo
