xixu-me
b792642ee2
Renamed and moved files into categorized directories for better organization. Categories include Shell-Programming, File-IO, Process-Control, and Signal-and-Piping.
84 lines
1.5 KiB
C
84 lines
1.5 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <string.h>
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int main(int argc, char *argv[]) {
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int pipefd[2]; // 管道文件描述符
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pid_t pid;
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int status;
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char buf[1024];
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long long sum = 0;
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long long num;
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// 获取输入n
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int n;
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if (argc > 1) {
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n = atoi(argv[1]);
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}
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else {
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printf("请输入一个整数: ");
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scanf("%d", &n);
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}
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// 创建管道
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if (pipe(pipefd) == -1) {
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perror("pipe");
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exit(EXIT_FAILURE);
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}
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// 创建子进程
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pid = fork();
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if (pid < 0) { // 创建子进程失败
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perror("fork");
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exit(EXIT_FAILURE);
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}
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else if (pid == 0) { // 子进程
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// 关闭管道读端
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close(pipefd[0]);
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// 将标准输出重定向到管道写端
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dup2(pipefd[1], STDOUT_FILENO);
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close(pipefd[1]);
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// 执行fabo程序，传入参数n
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char n_str[20];
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sprintf(n_str, "%d", n);
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execl("./fabo", "fabo", n_str, NULL);
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// 如果execl失败，则执行下面的代码
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perror("execl");
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exit(EXIT_FAILURE);
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}
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else { // 父进程
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// 关闭管道写端
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close(pipefd[1]);
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// 从管道读取子进程输出的每个斐波那契数，并计算总和
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FILE *fp = fdopen(pipefd[0], "r");
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if (fp == NULL) {
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perror("fdopen");
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exit(EXIT_FAILURE);
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}
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while (fgets(buf, sizeof(buf), fp) != NULL) {
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num = strtoll(buf, NULL, 10);
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sum += num;
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}
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// 关闭文件和管道读端
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fclose(fp);
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// 等待子进程结束
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waitpid(pid, &status, 0);
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// 打印总和
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printf("斐波那契数列前%d项的总和为: %lld\n", n, sum);
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}
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return 0;
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}
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