Re: Is it fair to say, "sed supports # comments starting any column"?

Thanks. I didn't see where the POSIX spec talked about ; syntax. It 
seems it should, because ; seems very useful. Just didn't see it. And of 
course my post was not about ; syntax, that's a different issue.

Consistent with what you said, POSIX says, "The treatment of '#' 
comments differs from the SVID which only allows a comment as the first 
line of the script, but matches BSD-derived implementations. The comment 
character is treated as a command, and it has the same properties in 
terms of being accepted with leading <blank> characters; the BSD 
implementation has historically supported this.". But it also says for # 
definition, "Ignore the '#' and the remainder of the line". In other 
words, the standard is to allow comments starting any column.

My questions #1 and #2 are at least partially answered, so that's a 
little progress. But if this is it, that's disappointing. Anybody else?

On 8/11/2015 1:35 AM, [email protected] [sed-users] wrote:
> Hi Daniel,
>
>   The POSIX spec does talk about the <semicolon> syntax, although it's not enforced.
>
>
>   The System V "sed" has this restriction that only the 1st line can be a
>   comment line, and then only if the first char. is #. (with #n as exception)
>
>
>   As to why some SEDs are not POSIX compliant in terms of the comment char I am not sure. Many times, things are a relic of the past when memory was at a premium & the sed versions may never have gotten upgraded.
>
>
>   Thanks,
>   Rakesh
>
>
> ---In [email protected], <dgoldman@...> wrote :
>
>   Hi Rakesh,
>
>   I know you are trying to help. But you didn't answer any of my
>   questions. :( I am not a newbie trying to learn sed. I have specific
>   questions I am looking for experts such as yourself to weigh in on.
>
>   You are probably aware that some sed versions do not support ; syntax.
>   Plus, the POSIX standard does not mention ; syntax. So offering ; as a
>   solution doesn't help anyway.
>
>   Personally, I think it is fair to say, "sed supports # comments starting
>   any column", since that is what POSIX says. I am looking for someone to
>   explain why that is not true.
>
>   Thanks,
>   Daniel
>
>   On 8/11/2015 12:23 AM, Rakesh Sharma [sed-users] wrote:
>   > I normally use the ";#" syntax to start comments. The semicolon would start a newline and the # would then start at the first column, thus satisfying both.
>   >
>   >
>   >> s/x/y/ # Silly comment 1
>   >
>   > s/x/y/ ;# Silly comment 1
>   >
>   > ________________________________
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
> Posted by: [email protected]
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>