Exec family of functions usage demo.

exec_family_and_printing.c

//exec() family of functions

#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv){
	pid_t id;

	id = vfork();
	if(id == 0){
		execl("./aux","execl",NULL);
	}
		
	id = vfork();
	if(id == 0){
		execlp("./aux","execlp",NULL);
	}
	
	id = vfork();
	if(id == 0){
		char *envar[] = {"DUMMY=dummyenv",NULL};
		execle("./aux","execle",NULL,envar);
	}
	
	id = vfork();
	if(id == 0){
		char *vc[] = {"execv"};
		execv("./aux",vc);
	}
	
	id = vfork();
	if(id == 0){
		char *vc[] = {"execvp","somearg",NULL};
		execvp("./aux",vc);
	}
	
	id = vfork();
	if(id == 0){
		char *vc[] = {"execvpe","somearg",NULL};
		char *ev[] = {"DUMMY=dummyenv",NULL};
		execvpe("./aux",vc,ev);
	}
	
	wait(10);
	printf("\n");
	return 0;
}


//Printing program for the above
#include <stdio.h>
int main(int argc, char** argv){
	printf("AUX: %d %s %s %s %s | ENV (DUMMY): %s\n",argc,argv[0],(argv[1])?argv[1]:"none",(argv[2])?argv[2]:"none",(argv[3])?argv[3]:"none",((char *)getenv("DUMMY"))?(char *)getenv("DUMMY"):"none");
	//return 0;
}