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Re: comments in import files

• To: mathgroup at smc.vnet.net
• Subject: [mg74663] Re: comments in import files
• From: rob <josh2499 at hotmail.com>
• Date: Fri, 30 Mar 2007 02:58:58 -0500 (EST)
• References: <eudd45$sdc$1@smc.vnet.net> <eufr25$7rm$1@smc.vnet.net>

Hi, I spent some time in the Help looking for "grep". It is 
listed is several places and appears to be associated with 
FindList. But I never found a single instance of the term 
"grep" mentioned anywhere after reading thru many pages.

Can you please give me some clue what it is? Thanks.

Szabolcs wrote:
> On Mar 28, 11:39 am, "beheiger" <beheiger at hotmail.com> wrote:
> 
>>Hi,
>>
>>I would like to know if Mathematica can handle comments in import files.
>>In particular, I would like to add lines of comments to an
>><emptyspace>-separated
>>ASCII table (say, "results.dat") that I produced with other programs.
>>However,
>>I can't seem to find anything on how to write these comments in such a way
>>that
>>Mathematica's function, used as
>>
>>Import["results.dat","Table"];
>>
>>does not complain. Help is appreciated.
>>
>>Regards, Andy
> 
> 
> If nobody else posts a better solution (I hope that someone will), you
> can use the grep program to strip out the comments, e.g.
> readTable[filename_] := (Run["grep", "-v", "^#", filename, ">", "c:\
> \temp\\tmpfile"]; Import["tmpfile", "Table"])
> 
> (This will remove lines starting with #.)
> 
> Of course you can also use Mathematica to read the file line by line
> and strip out the comments, but it may be slow with large datasets.
> 
>