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How to prevent a C++ program reading a file that is still being written to.?

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Top Forums Programming How to prevent a C++ program reading a file that is still being written to.?
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Old 06-26-2014
The only way to know the file has been completely written is to have the writing process signal success in some way. Because only the writing process knows if it has successfully written all the data supposed to be in the file. The receiving process can not infer that accurately because of failure conditions, so any method based on timestamps or something similar can not be guaranteed to work.

Period.

Renaming the file is probably the best way to do that.

There are some kludges you can use on Solaris using the utssys() call that will return the process IDs of process that have any file open, but that will just tell you the file is open and won't tell you why the process has the file open, nor why it closed it. Look at the "sys/utssys.h" header file.

If you can find the source code for the Solaris "fuser" utility, you can see an example of how to use it.

Or you can run the "fuser" utility in a subprocess using system() or popen().
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LEARN ABOUT DEBIAN

smpppd-c.conf

SMPPPD-C.CONF(5)						      SMPPPD							  SMPPPD-C.CONF(5)

NAME

       smpppd-c.conf - configuration file for smpppd frontends

DESCRIPTION

       When frontends of smpppd like cinternet , qinternet or kinternet want to connect the smpppd they may read the file /etc/smpppd-c.conf.

       The configuration file /etc/smpppd-c.conf has a simple file format with a key = value pair in each line.

OPTIONS

       sites = <list of sites>
	      Tell the frontends where to find the smpppd.  Frontends will try to connect to the smpppd in the order defined here.  Possible sites
	      are:

	      local  Connect to locally running smpppd (via socket in the local namespace).

	      gateway
		     Connect to smpppd running on the gateway.

	      config-file
		     Connect to smpppd as specified in this file.

	      slp    Connect to smpppd as retrived from the slp daemon (service location protocol).

       server = <server>
	      Specifies the host on which the smpppd is running.

       port = <port>
	      Specifies the port number of the smpppd.

       password = <password>
	      The password to use for authentication at the smpppd, UTF-8 encoded for those who really care.

SEE ALSO

       kinternet, qinternet, cinternet(1), smpppd(8).

AUTHOR

       Arvin Schnell <arvin@suse.de>

SuSE								   January 2004 						  SMPPPD-C.CONF(5)