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.
75 lines
1.5 KiB
C
75 lines
1.5 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <fcntl.h>
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#include <unistd.h>
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int main() {
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int pack_fd, file_fd;
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char buffer[4096];
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ssize_t bytes_read;
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// 打开打包文件
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pack_fd = open("a.pack", O_RDONLY);
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if (pack_fd == -1) {
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perror("无法打开打包文件");
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return 1;
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}
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// 读取并解包文件
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while (1) {
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int name_len, file_size;
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// 读取文件名长度
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if (read(pack_fd, &name_len, sizeof(int)) <= 0) {
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// 到达文件末尾或出错
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break;
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}
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// 读取文件名
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char *filename = (char *)malloc(name_len + 1);
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if (filename == NULL) {
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perror("内存分配失败");
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close(pack_fd);
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return 1;
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}
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read(pack_fd, filename, name_len);
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filename[name_len] = '\0'; // 添加字符串结束符
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// 读取文件大小
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read(pack_fd, &file_size, sizeof(int));
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printf("正在解包: %s (%d 字节)\n", filename, file_size);
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// 创建目标文件
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file_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
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if (file_fd == -1) {
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perror("无法创建目标文件");
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free(filename);
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continue;
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}
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// 拷贝文件数据
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int remaining = file_size;
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while (remaining > 0) {
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int to_read = (remaining < sizeof(buffer)) ? remaining : sizeof(buffer);
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bytes_read = read(pack_fd, buffer, to_read);
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if (bytes_read <= 0) {
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perror("读取文件数据失败");
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break;
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}
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write(file_fd, buffer, bytes_read);
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remaining -= bytes_read;
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}
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close(file_fd);
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free(filename);
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}
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close(pack_fd);
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printf("解包完成\n");
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return 0;
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}
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