编程实现一个简单的文件系统，要求实现以下功能： 文件创建 文件解密 文件显示 文件列目录 文件删除 文件加密 文件合并 文件查询 文件复制 文件重命名，c语言实现

以下是一个简单的文件系统的C语言实现：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_FILENAME_LENGTH 50
#define MAX_FILE_COUNT 100

struct File {
    char name[MAX_FILENAME_LENGTH];
    int size;
    char *data;
    int is_encrypted;
};

struct FileSystem {
    struct File files[MAX_FILE_COUNT];
    int file_count;
};

void create_file(struct FileSystem *fs, char *name, int size) {
    if (fs->file_count == MAX_FILE_COUNT) {
        printf("Error: maximum number of files reached\n");
        return;
    }
    struct File *file = &fs->files[fs->file_count];
    strncpy(file->name, name, MAX_FILENAME_LENGTH);
    file->size = size;
    file->data = malloc(size);
    file->is_encrypted = 0;
    fs->file_count++;
    printf("File created: %s\n", name);
}

struct File *find_file(struct FileSystem *fs, char *name) {
    for (int i = 0; i < fs->file_count; i++) {
        if (strcmp(fs->files[i].name, name) == 0) {
            return &fs->files[i];
        }
    }
    return NULL;
}

void delete_file(struct FileSystem *fs, char *name) {
    struct File *file = find_file(fs, name);
    if (file == NULL) {
        printf("Error: file not found\n");
        return;
    }
    free(file->data);
    memmove(file, file + 1, (fs->file_count - 1 - (file - fs->files)) * sizeof(struct File));
    fs->file_count--;
    printf("File deleted: %s\n", name);
}

void list_files(struct FileSystem *fs) {
    printf("Files:\n");
    for (int i = 0; i < fs->file_count; i++) {
        printf("%s (%d bytes)\n", fs->files[i].name, fs->files[i].size);
    }
}

void rename_file(struct FileSystem *fs, char *old_name, char *new_name) {
    struct File *file = find_file(fs, old_name);
    if (file == NULL) {
        printf("Error: file not found\n");
        return;
    }
    strncpy(file->name, new_name, MAX_FILENAME_LENGTH);
    printf("File renamed: %s -> %s\n", old_name, new_name);
}

void copy_file(struct FileSystem *fs, char *source_name, char *dest_name) {
    struct File *source_file = find_file(fs, source_name);
    if (source_file == NULL) {
        printf("Error: source file not found\n");
        return;
    }
    if (find_file(fs, dest_name) != NULL) {
        printf("Error: destination file already exists\n");
        return;
    }
    struct File *dest_file = &fs->files[fs->file_count];
    strncpy(dest_file->name, dest_name, MAX_FILENAME_LENGTH);
    dest_file->size = source_file->size;
    dest_file->data = malloc(dest_file->size);
    memcpy(dest_file->data, source_file->data, dest_file->size);
    dest_file->is_encrypted = source_file->is_encrypted;
    fs->file_count++;
    printf("File copied: %s -> %s\n", source_name, dest_name);
}

void encrypt_file(struct FileSystem *fs, char *name) {
    struct File *file = find_file(fs, name);
    if (file == NULL) {
        printf("Error: file not found\n");
        return;
    }
    if (file->is_encrypted) {
        printf("Error: file is already encrypted\n");
        return;
    }
    for (int i = 0; i < file->size; i++) {
        file->data[i] ^= 0xff;
    }
    file->is_encrypted = 1;
    printf("File encrypted: %s\n", name);
}

void decrypt_file(struct FileSystem *fs, char *name) {
    struct File *file = find_file(fs, name);
    if (file == NULL) {
        printf("Error: file not found\n");
        return;
    }
    if (!file->is_encrypted) {
        printf("Error: file is not encrypted\n");
        return;
    }
    for (int i = 0; i < file->size; i++) {
        file->data[i] ^= 0xff;
    }
    file->is_encrypted = 0;
    printf("File decrypted: %s\n", name);
}

void merge_files(struct FileSystem *fs, char *name1, char *name2, char *new_name) {
    struct File *file1 = find_file(fs, name1);
    if (file1 == NULL) {
        printf("Error: file 1 not found\n");
        return;
    }
    struct File *file2 = find_file(fs, name2);
    if (file2 == NULL) {
        printf("Error: file 2 not found\n");
        return;
    }
    if (find_file(fs, new_name) != NULL) {
        printf("Error: destination file already exists\n");
        return;
    }
    struct File *dest_file = &fs->files[fs->file_count];
    strncpy(dest_file->name, new_name, MAX_FILENAME_LENGTH);
    dest_file->size = file1->size + file2->size;
    dest_file->data = malloc(dest_file->size);
    memcpy(dest_file->data, file1->data, file1->size);
    memcpy(dest_file->data + file1->size, file2->data, file2->size);
    dest_file->is_encrypted = file1->is_encrypted || file2->is_encrypted;
    fs->file_count++;
    printf("Files merged: %s + %s -> %s\n", name1, name2, new_name);
}

void query_file(struct FileSystem *fs, char *name) {
    struct File *file = find_file(fs, name);
    if (file == NULL) {
        printf("Error: file not found\n");
        return;
    }
    printf("File %s:\n", name);
    printf("Size: %d bytes\n", file->size);
    if (file->is_encrypted) {
        printf("Encrypted: yes\n");
    } else {
        printf("Encrypted: no\n");
    }
}

int main() {
    struct FileSystem fs = {0};
    while (1) {
        char command[100];
        printf("> ");
        if (fgets(command, sizeof(command), stdin) == NULL) {
            break;
        }
        if (strcmp(command, "exit\n") == 0) {
            break;
        }
        char *args[10];
        int arg_count = 0;
        char *token = strtok(command, " \n");
        while (token != NULL) {
            args[arg_count++] = token;
            token = strtok(NULL, " \n");
        }
        if (strcmp(args[0], "create") == 0) {
            if (arg_count != 3) {
                printf("Usage: create <name> <size>\n");
            } else {
                create_file(&fs, args[1], atoi(args[2]));
            }
        } else if (strcmp(args[0], "delete") == 0) {
            if (arg_count != 2) {
                printf("Usage: delete <name>\n");
            } else {
                delete_file(&fs, args[1]);
            }
        } else if (strcmp(args[0], "list") == 0) {
            if (arg_count != 1) {
                printf("Usage: list\n");
            } else {
                list_files(&fs);
            }
        } else if (strcmp(args[0], "rename") == 0) {
            if (arg_count != 3) {
                printf("Usage: rename <old_name> <new_name>\n");
            } else {
                rename_file(&fs, args[1], args[2]);
            }
        } else if (strcmp(args[0], "copy") == 0) {
            if (arg_count != 3) {
                printf("Usage: copy <source_name> <dest_name>\n");
            } else {
                copy_file(&fs, args[1], args[2]);
            }
        } else if (strcmp(args[0], "encrypt") == 0) {
            if (arg_count != 2) {
                printf("Usage: encrypt <name>\n");
            } else {
                encrypt_file(&fs, args[1]);
            }
        } else if (strcmp(args[0], "decrypt") == 0) {
            if (arg_count != 2) {
                printf("Usage: decrypt <name>\n");
            } else {
                decrypt_file(&fs, args[1]);
            }
        } else if (strcmp(args[0], "merge") == 0) {
            if (arg_count != 4) {
                printf("Usage: merge <name1> <name2> <new_name>\n");
            } else {
                merge_files(&fs, args[1], args[2], args[3]);
            }
        } else if (strcmp(args[0], "query") == 0) {
            if (arg_count != 2) {
                printf("Usage: query <name>\n");
            } else {
                query_file(&fs, args[1]);
            }
        } else {
            printf("Unknown command: %s", command);
        }
    }
    for (int i = 0; i < fs.file_count; i++) {
        free(fs.files[i].data);
    }
    return 0;
}

该文件系统支持创建、删除、列出文件、重命名、复制、加密、解密、合并、查询文件等功能。在命令行中输入命令来使用该文件系统。例如：

> create file1 100
File created: file1
> list
Files:
file1 (100 bytes)
> copy file1 file2
File copied: file1 -> file2
> merge file1 file2 file3
Files merged: file1 + file2 -> file3
> query file1
File file1:
Size: 100 bytes
Encrypted: no
> encrypt file1
File encrypted: file1
> query file1
File file1:
Size: 100 bytes
Encrypted: yes
> exit