最近在看深入理解計算機系統(tǒng)，看到一個函數(shù)叫做execve()，這個函數(shù)很有意思，可以在一個進程插入另外一個進程執(zhí)行，但是又不像fork()一樣產(chǎn)生一個子進程，execve()插入的進程和原進程共享進程號，就好像執(zhí)行這進程就像執(zhí)行過程調(diào)用一般隨意。
函數(shù)原型如下：
int execve(const char *filename, char *const argv[], char *const envp[]);
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 <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { int j; for (j = 0; j < argc; j++) printf("argv[%d]: %s\n", j, argv[j]); exit(EXIT_SUCCESS); } This program can be used to exec the program named in its command-line argument: /* execve.c */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main(int argc, char *argv[]) { char *newargv[] = { NULL, "hello", "world", NULL }; char *newenviron[] = { NULL }; if (argc != 2) { fprintf(stderr, "Usage: %s <file-to-exec>\n", 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
插入一個shell腳本執(zhí)行：
#include <stdio.h>#include <stdlib.h>#include <unistd.h>intmain(int argc, char *argv[]){ char *newargv[] = { "/etc" }; char *newenviron[] = { NULL }; if (argc != 2) { fprintf(stderr, "Usage: %s <file-to-exec>\n", argv[0]); exit(EXIT_FAILURE); } newargv[0] = argv[1]; execve(argv[1], newargv, newenviron); perror("execve"); /* execve() only returns on error */ exit(EXIT_FAILURE);}
script.sh如下：
#!/bin/bashls
執(zhí)行：
./execve ./script.sh
會在當前終端下輸出所有的文件
yca@ubuntu:~/桌面/hello$ ./execve ./script.sh 1 execve hello1 hello3 hello5 hello_lex1.txt execve.c hello1.c hello3.cpp hello5.c k_maxBubble hello hello1.o hello3.o hello5.o k_max.cBubble.c hello.c hello2.c hello3.s hello5.s lex.yy.cQuickSort.c hello.lex hello2.o hello4 hello5.s1 script.shQuicksort1.c hello.sh hello2.s hello4.c hello51.s
很好很強大~~
