user1779646 user1779646 - 8 months ago 42
Bash Question

Changing the directory of the shell through a C++ program

I'm trying to write a simple C++ program to execute Linux commands. I'm stuck at changing the directories (commands like

don't work). This is what I have so far:

system("echo -n '1. Current Directory is '; pwd");
system("chdir Desktop");


This is not possible, if you want to change the directory (i.e. cd, that is chdir(2) ...) of the shell which has invoked your program. So cd has to be a bash(1) builtin.

The reason is that chdir affects only the calling process (which would be your C program) not the parent process. Each process has its own current directory.

If you call system(3) it will fork(2) a new shell and execve(2) /bin/sh -c so only the forked shell can change its current directory.

You need to read Advanced Linux Programming.

Perhaps you want to call chdir directly inside your C program. This will affect the current process and all future child processes (including those started with system or popen library functions inside your C code) till their termination or some further call to chdir. But it won't affect the shell in your terminal (where you started your C program).