Hi everybody,
I am using the STL "ofstream" class.
I open a file using "ofstream" in update at the end mode ("ate"), I can read and
write my file correctly.
=> What I would like to do is deleting some lines from the file which decreases
the size of the file.
For performance reasons, I DO NOT WANT to close and open the file each time I
want to delete some information in it (I know that you can overwrite the file
content by re-opening the file)
I only found methods which allow you to add some information but no methods for
deleting the information.
Any idea will be welcome !
Thanks in advance.
Paul
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Paul LAURENT wrote: Hi everybody,
I am using the STL "ofstream" class.
There is no STL, ofstream, or class in standard C. You may want the
folks across the hall in news:comp.lang. c++.
{However, the answer to your issue is still the same, see below}.
I open a file using "ofstream" in update at the end mode ("ate"), I can read and
write my file correctly.
=> What I would like to do is deleting some lines from the file which decreases
the size of the file.
For performance reasons, I DO NOT WANT to close and open the file each time I
want to delete some information in it (I know that you can overwrite the file
content by re-opening the file)
Yes, but overwriting does not guarantee adjusting the end of the file to
the last used record.
I only found methods which allow you to add some information but no methods for
deleting the information.
Any idea will be welcome !
Thanks in advance.
Paul
Unfortunately, there is no process in _standard_ C to truncate a file
by delete portions of it. The portable method is to copy the portions
of the old file to a new file and then delete the old file {you could
rename the new file at this point}.
However, your platform may have some specific functions to perform
what you want. Ask the experts in a newsgroup about your platform.
--
Thomas Matthews
C++ newsgroup welcome message: http://www.slack.net/~shiva/welcome.txt
C++ Faq: http://www.parashift.com/c++-faq-lite
C Faq: http://www.eskimo.com/~scs/c-faq/top.html
alt.comp.lang.l earn.c-c++ faq: http://www.raos.demon.uk/acllc-c++/faq.html
Other sites: http://www.josuttis.com -- C++ STL Library book
Paul LAURENT wrote:
I am using the STL "ofstream" class.
c.l.c++ is over thataway --------->
--
Chuck F (cb********@yah oo.com) (cb********@wor ldnet.att.net)
Available for consulting/temporary embedded and systems.
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