Linux exec函数的使用

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; 
}

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_tfifo_read.c   fork_1.c  hello.cmsg_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。