deleting row in csv file

>> hello,
>>
>> i have made a script to read/add and update rows in an csv file.
>> it works fine.
>>
>> but when i change an existing row i want the original row to disapear.
>> now i get two rows: the original one en the changed one.
>>
>> so my question is: how can i delete a row in a csv file?
>>
>
> open source file, create a temporary file. Copy any line to the temporary
> file but the one you want to delete. Afterwards, move the temporary files
> to the original source file.
>
> Regards
> Stefan

Tricky if more than one user at a time... I would have the CSV file imported
into MySQL (or whatever database server you use), then once the data is
manipulated, export to the CSV. Or export to CSV on demand, or on schedule.
 >> Stay informed about: deleting row in csv file 

JDS wrote:
> On Mon, 24 Oct 2005 16:06:48 +0200, nescio wrote:
>
>
>>so my question is: how can i delete a row in a csv file?
>
>
> The question is, how are you reading, updating, and rewriting to the file?
>
> I recommend using file() to read the file into an array.
>
> Then update the value of the array
>
> Then write the value of the array back out to the file, overwriting the
> old file in the process. Use fopen() and fwrite().
>

Well this is what I would do in any other programming language (except java). But since
php has memory restrictions (mostly 8MB) I wouldn't recommend such a way, without knowing
the worst case (max size of the file). Just to mention.

Regards
Stefan
 >> Stay informed about: deleting row in csv file 

> I recommend using file() to read the file into an array.
>
> Then update the value of the array
>
> Then write the value of the array back out to the file, overwriting the
> old file in the process. Use fopen() and fwrite().


it is a small file, and they don't use a database, and they have only a few
users.

so this looks a very effective solution.

thanks for your help
 >> Stay informed about: deleting row in csv file 

| But since php has memory restrictions (mostly 8MB)

uhhh...try 2GB.
 >> Stay informed about: deleting row in csv file 

steve wrote:
> | But since php has memory restrictions (mostly 8MB)
>
> uhhh...try 2GB.
>
Tell this your provider! If you have your own server with not that much concurrent scripts
running, setting the memore restrictions to a higher level is fine but not always possible .

Regards
Stefan
 >> Stay informed about: deleting row in csv file 

| > | But since php has memory restrictions (mostly 8MB)
| >
| > uhhh...try 2GB.
| >
| Tell this your provider! If you have your own server with not that much
concurrent scripts
| running, setting the memore restrictions to a higher level is fine but not
always possible .

what restrictions my provider may employ have *no* bearing on php's string
memory limit which *is* 2gb and not "mostly" 8mb. your statement is
inaccurate. i was speaking to the inaccuracy of your claim...if you meant
"limits of most providers", you should have said so. if you meant "server
restrictions", you should have said so.
 >> Stay informed about: deleting row in csv file 

The old fashioned way was to have a 'deleted' flag in the CSV file, instead
of removing a line simply set the deleted flag, i.e. one field, when you
parse the CSV file look for the deleted flag, if set the line is 'deleted'
so ignore it.

Once in a while go through the CSV file and physically remove all rows
flagged as deleted, if your CSV file is getting too big.

Now the next problem is what if 2 people are writing to the file at the
'same time'?

--

Ted Ferenc
This address used is maintained only for newsgroup posting.
Mail sent there may not be read by me for several days.
"nescio" wrote in message

> hello,
>
> i have made a script to read/add and update rows in an csv file.
> it works fine.
>
> but when i change an existing row i want the original row to disapear.
> now i get two rows: the original one en the changed one.
>
> so my question is: how can i delete a row in a csv file?
>
>
> thanks
>
>
 >> Stay informed about: deleting row in csv file