Linux的exec族函数使用示例

1. 示例

 /*exec函数示例*/
 #include <stdio.h>
 #include <unistd.h>

 int main(void)
 {
     int flag;
     pid_t pid;
     char *const argv[] = {"%U", "--user-data-dir=/home/Administrator/.chromiun", NULL};
     //exec把当前进程印象替换成新的程序文件，故调用进程被覆盖

     // 如果不指定全路径，则只检查PATH变量中存储的命令
     if((pid = fork())==0) {
         printf("in child process 1......\n");
         //flag = execvp("./hello", NULL);
         //envp变量的用
         char *envp[]={"PATH=.", NULL};
         flag = execve("hello", NULL, envp);
         if(flag == -1)
             printf("exec error!\n");
     }

     if((pid = fork())==0) {
         printf("in child process 2......\n");
         //执行ls命令
         flag = execlp("ls", "-al", NULL);
         if(flag == -1)
             printf("exec error!\n");
     }

     if((pid = fork())==0) {
         printf("in child process 3......\n");
         //启动chrome浏览器
         flag = execv("/usr/bin/chromium-browser", argv);
         if(flag == -1)
             printf("exec error!\n");
     }
     printf("in parent process ......\n");
     return 0;
 }

整理函数直接可使用为如下：

static int CreateSubProcessAndExecv(const char* executableFile_,
		char* const argvs[] )
{
	//char *const argv[] = {"%U", "--user-data-dir=/home/Administrator/.chromiun", NULL};
    pid_t pid;
    if((pid = fork()) == -1) {
        printf("Error in fork\n!\n!\n!\n");
        exit(1);
    }
    if(pid == 0) {
        printf("spawning sub process \n");
        execv(executableFile_,
        		argvs);
        exit(0);
    }
    return pid ;
}

2. hello程序

 #include <stdio.h>

 int main(void)
 {
     printf("Hello world!\n");
     return 0;
 }

3. 运行结果

 root@ubuntu:.../Linux_C/Process# ./exec_t
 in child process 1......
 in parent process ......
 in child process 3......
 root@ubuntu:.../Linux_C/Process# in child process 2......
 Hello world!
 exec_t    fifo_read.c   fork_1.c  hello.c    msg_send.c   signal_1.c
 exec_t.c  fifo_write.c  hello     msg_receive.c  semop_P_V.c
 已在现有的浏览器会话中创建新的窗口。