C System

programming C MOC

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Most of the commands are all programs and likely written in C. The system() method in the stdlib.h library allows accessing the terminal.

However, make sure users don’t have access to the system().

#include <stdio.h>
#include <stdlib.h>
 
int main() {
	system("ls");
	return 0;
}

Ephemeral Commands

Each call to system() starts over, so changing directory in one command doesn’t affect the next command. To run commands consecutively chain the commands.

#include <stdio.h>
#include <stdlib.h>
 
int main() {
	system("cd /"); // Change to home directory
	system("ls"); // Doesn't print home directory
 
	system("cd / && ls"); // Prints home directory
	system("cd /; ls"); // This also works
 
	return 0;
}

Launching Programs

C can also launch bigger binaries, like chrome.