Linux_fork 进程操作demo

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
system("ls -l");

printf("end!\n");

return 0;
}

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

int main(void)
{
char * env[] = {"PATH=/bin", 0};
char * argv[] = {"ls", "-l", 0};

printf("ready...\n");

//printf("****************execl**************\n");
//execl("ls", "ls", "-l", 0);

printf("****************execlp**************\n");
execlp("ls", "ls", "-l", 0);

//printf("****************execle**************\n");
//execle("/bin/ls", "ls", "-l", 0, env);

//printf("****************execv**************\n");
//execv("/bin/ls", argv);

//printf("****************execvp**************\n");
//execvp("ls", argv);

//printf("****************execve**************\n");
//execve("/bin/ls", argv, env);

printf("end!\n");
return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
int pid;
char *msg;
int n;

printf("father process begin...\n");

pid = fork();

if (pid == -1) {
printf("fork error!\n");
exit(1);
} else if (pid == 0) {
printf("In child process!\n");
msg = "child process ";
n = 2;
}  else {
printf("In father process!\n");
msg = "father process ";
n = 1;
}

while(n--) {
printf("%s\n", msg);
sleep(1);
}

printf("%s end!\n", msg);

return 0;
}

#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
int pid;
char *msg;
int status;
int child_pid;
int n;

printf("father process begin...\n");

pid = fork();

if (pid == -1) {
printf("fork error!\n");
exit(1);
} else if (pid == 0) {
printf("In child process!\n");
msg = "child process ";
n = 3;
}  else {
printf("In father process!\n");
msg = "father process ";
n = 1;
}

while(n--) {
printf("%s\n", msg);
sleep(1);
}

if (pid) {
printf("father process wait...\n");
child_pid = wait(&status);
if (WIFEXITED(status)) {
printf("Wait finished and child process terminated normally, child pid = %d\n", child_pid);
} else {
printf("Wait finished and child process terminated unnormally, child pid = %d\n", child_pid);
}
}

printf("%s end!\n", msg);

return 0;
}

#include <sys/types.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
int pid;
char *msg;
int status;
int child_pid;
int n;

printf("father process begin...\n");

pid = fork();

if (pid == -1) {
printf("fork error!\n");
exit(1);
} else if (pid == 0) {
printf("In child process!\n");
msg = "child process ";
n = 1;
}  else {
printf("In father process!\n");
msg = "father process ";
n = 10;
}

while(n--) {
printf("%s\n", msg);
sleep(5);
}

if (pid) {
printf("father process wait...\n");
child_pid = wait(&status);
if (WIFEXITED(status)) {
printf("Wait finished and child process terminated normally, child pid = %d\n", child_pid);
} else {
printf("Wait finished and child process terminated unnormally, child pid = %d\n", child_pid);
}
}

printf("%s end!\n", msg);

return 0;
}

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
int pid;
int i;

for (i=0; i<10; i++) {
pid = fork();
if (pid == -1) {

perror("fork error!\n");
exit(1);
} else if (pid == 0) {
//printf("Start run a new child pid, pid=%d\n", getpid());
} else {
//printf("Add a new child, pid = %d\n", pid);
}
}

printf("My pid = %d\n", getpid());

return 0;
}