File Handling

[VisBasDude]

Hi, yeah i was wondering when i want to write records to a file but say in record 2 instead of at the end of the records then how is this best done. I am wanting to do this so that i can edit records after they have been created. Anyone got any ideas how its best to go about this? Thanx JP

 

[CliveC]

This is how to open a file for reading and writing with the file position indicator at the end of the file.

$filePointer = fopen("mydata.txt", "a+&quot

To open for reading and writing at the start of the file use r+ instead of a+. Clive

http://tubularity.com

 

[VisBasDude]

How do i then tell the script where to write the details?

 

[danielhozac]

Use the [tt]fseek[/tt] function.

http://www.php.net/manual/en/function.fseek.php

//Daniel

 

[VisBasDude]

Does anyone have an example of this or know where a clear example is??

 

[sleipnir214]

fseek() is clunky. Since you have to position the file pointer by bytes, you have to keep track of at which byte each line begines.

And since a file is a stream of records, if you write 20 bytes to a 15-byte line, you've just overwritten part of the next line.

[v]VisBasDude[/b]:
Do you have a database server available to you? MySQL or something? Modifying records via a database server is a lot easier than trying to reinvent it yourself. Want the best answers? Ask the best questions:

http://www.tuxedo.org/~esr/faqs/smart-questions.html

TANSTAAFL!

 

[VisBasDude]

Nah im using a file based system. Suppose i could create a temp file and put in the new data at the correct position and then just rename it! Do you think that would work?

 

[sleipnir214]

That would be the way I recommend. Trying to write to the middle of a file in situ is more trouble that it's worth. Want the best answers? Ask the best questions:

http://www.tuxedo.org/~esr/faqs/smart-questions.html

TANSTAAFL!