Organize files into categorized directories

Renamed and moved files into categorized directories for better organization. Categories include Shell-Programming, File-IO, Process-Control, and Signal-and-Piping.

2_File-IO/unpack_v1.c

@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int main() {
+	int pack_fd, file_fd;
+	char buffer[4096];
+	ssize_t bytes_read;
+
+	// 打开打包文件
+	pack_fd = open("a.pack", O_RDONLY);
+	if (pack_fd == -1) {
+		perror("无法打开打包文件");
+		return 1;
+	}
+
+	// 读取并解包文件
+	while (1) {
+		int name_len, file_size;
+
+		// 读取文件名长度
+		if (read(pack_fd, &name_len, sizeof(int)) <= 0) {
+			// 到达文件末尾或出错
+			break;
+		}
+
+		// 读取文件名
+		char *filename = (char *)malloc(name_len + 1);
+		if (filename == NULL) {
+			perror("内存分配失败");
+			close(pack_fd);
+			return 1;
+		}
+
+		read(pack_fd, filename, name_len);
+		filename[name_len] = '\0'; // 添加字符串结束符
+
+		// 读取文件大小
+		read(pack_fd, &file_size, sizeof(int));
+
+		printf("正在解包: %s (%d 字节)\n", filename, file_size);
+
+		// 创建目标文件
+		file_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		if (file_fd == -1) {
+			perror("无法创建目标文件");
+			free(filename);
+			continue;
+		}
+
+		// 拷贝文件数据
+		int remaining = file_size;
+		while (remaining > 0) {
+			int to_read = (remaining < sizeof(buffer)) ? remaining : sizeof(buffer);
+			bytes_read = read(pack_fd, buffer, to_read);
+			if (bytes_read <= 0) {
+				perror("读取文件数据失败");
+				break;
+			}
+
+			write(file_fd, buffer, bytes_read);
+			remaining -= bytes_read;
+		}
+
+		close(file_fd);
+		free(filename);
+	}
+
+	close(pack_fd);
+	printf("解包完成\n");
+	return 0;
+}