嵌入式

linux下C程序插入执行shell脚本

2019-07-13 06:56发布

站内文章 / 嵌入式Linux
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最近在看深入理解计算机系统，看到一个函数叫做execve()，这个函数很有意思，可以在一个进程插入另外一个进程执行，但是又不像fork()一样产生一个子进程，execve()插入的进程和原进程共享进程号，就好像执行这进程就像执行过程调用一般随意。函数原型如下：int execve(const char *filename, char *const argv[], char *const envp[]);复制代码EXAMPLE The following program is designed to be execed by the second program below. It just echoes its command-line one per line. /* myecho.c */ #include #include int main(int argc, char *argv[]) { int j; for (j = 0; j < argc; j++) printf("argv[%d]: %s ", j, argv[j]); exit(EXIT_SUCCESS); } This program can be used to exec the program named in its command-line argument: /* execve.c */ #include #include #include int main(int argc, char *argv[]) { char *newargv[] = { NULL, "hello", "world", NULL }; char *newenviron[] = { NULL }; if (argc != 2) { fprintf(stderr, "Usage: %s ", argv[0]); exit(EXIT_FAILURE); } newargv[0] = argv[1]; execve(argv[1], newargv, newenviron); perror("execve"); /* execve() only returns on error */ exit(EXIT_FAILURE); } We can use the second program to exec the first as follows: $ cc myecho.c -o myecho $ cc execve.c -o execve $ ./execve ./myecho argv[0]: ./myecho argv[1]: hello argv[2]: world复制代码插入一个shell脚本执行：复制代码#include #include #include int main(int argc, char *argv[]) { char *newargv[] = { "/etc" }; char *newenviron[] = { NULL }; if (argc != 2) { fprintf(stderr, "Usage: %s ", argv[0]); exit(EXIT_FAILURE); } newargv[0] = argv[1]; execve(argv[1], newargv, newenviron); perror("execve"); /* execve() only returns on error */ exit(EXIT_FAILURE); }复制代码script.sh如下：#!/bin/bash ls 执行：./execve ./script.sh会在当前终端下输出所有的文件复制代码yca@ubuntu:~/桌面/hello$ ./execve ./script.sh 1 execve hello1 hello3 hello5 hello_lex 1.txt execve.c hello1.c hello3.cpp hello5.c k_max Bubble hello hello1.o hello3.o hello5.o k_max.c Bubble.c hello.c hello2.c hello3.s hello5.s lex.yy.c QuickSort.c hello.lex hello2.o hello4 hello5.s1 script.sh Quicksort1.c hello.sh hello2.s hello4.c hello51.s复制代码很好很强大~~

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