I want to run a ftp from c++ asynchronously perhaps using bash
 

I want to run a ftp from c++ asynchronously. For example:

Using the following bash command:
//ftp -in <ip address> <<HERE
//user <user> <password>
//put <filename>
//bye
//HERE

Inserted into a c++ system call:

system ("ftp -in 1.2.3.4 <<HERE\nuser username password\nput filename\nbye\nHERE&");

Note I want the ftp to run asynchronously thus at the end of the bash command I have '&'.

Will using $? give the the result of the ftp transfer, thus because of the '&' does $? still work? For example can I then just do the following:

system("if [ $? -eq 0 ]; then\n do something\nfi")

Is there a better way?

How do I know the process has finsihed, do I have to monitor the process?

Should the ftp command just be in a phtread?

Hello DEF. :)

Do you want the compiled C++ executable to wait for the FTP process to complete or to come back later and see what happened?

AFAIK, each system( ) call starts a new shell (which may or may not exit, depending on what you make it do); it's not like it there's one shell that you can keep dipping back into.

Thus you can't use to access the exit status from the precedingYou need some inter-process communication between the process (tree) that you kick off from the compiled C++ executable to do the FTP work back to the compiled C++ executable. The simplest mechanism (conceptually and to debug) is to have the process (tree) doing the FTP work to write to a file and then read that file in the compiled C++ executable.

As with all asynchronous processes you need to time-coordinate between them; yes, you will have to "monitor the process" to see if it has finished before you can check how it went.

I don't C++ but guess the system() call returns the PID of the process it initiated. Presumably there's another function you can call from C++ to query a process by giving its PID. Beware the PID may be re-used!

Best

Charles

I don't suppose you've heard of
netrc

and maybe:

ftp -N netrc

man ftp

P.S. I don't know about phtreads but, if you can multi-thread then setting up a thread to run the system call that starts the FTP work and not using "&" would be a neat way to pick up the exit status, from the system()'s return value.

Asynchronous processes are non-trivial to work with -- way easier to go synchronous if you have the option.

catkin: Your comments make sense so I have done what you said and used pthreads.

bigearsbilly: I wasn't sure how I am suppose to use this configuration file to solve my problem?