The problem with the dynamic Qt library on Linux

Question

I built a QuickFIX Engine-based application in Qt called fixapp ; It works great. My broker asked me to specify a local port to connect to them. Then I could not find such a configuration file, so I changed the source code of QuickFix.

I used the tradeclient and executor examples obtained by QuickFIX source code for testing. It works. tradeclient binds to the local port specified in the configuration file.

However, when I go to fixapp using the library created by the modified QuickFIX source code, it does not bind to the specified local port. It seems that the modified part has not changed the behavior of the program.

What are the potential issues here?

Update: I tried to set some breakpoints in the QuickFix source code. In one cpp file that I changed, my breakpoint is ignored. This is debug mode, not release mode. I feel like it is running the old cpp file and showing the new cpp file.

Answer 1

The applicant found that the fastfix library path is .../quickfix/lib , and the path that I link to the external lib in fixapp is also .../quickfix/lib . However, when he checked the library path in /usr/lib , the library is still old. As soon as he replaced the value in /usr/lib , fixapp started working. He does not know why the path to which he refers in Qt does not work, but /usr/lib works.