system ("cd ..");
This doesn’t produce any error but also doesn’t do anything meaningful. Why?
system (cd ..); This doesn’t produce any error but also doesn’t do anything meaningful.
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system ("cd ..");
This doesn’t produce any error but also doesn’t do anything meaningful. Why?
The
system()function makes afork()that creates a process being a copy of the initial one.The current directory depends on the environment of a process (it is stored within the environment variables of a process). Thus when the child process, having its own environment, makes a
cd, that affects only the child process, not the parent.Parent process: in /home/x/y
Child process (after the fork): in /home/x/y
Doing a
cd ..in the child process sets its local environment to /home/xBut the parent process is still in /home/x/y
Parent process waits for child to complete the
systemcall, then continue its own execution having its own environment (current directory) unchanged.