请用C语言编写一个文件管理系统

作为AI语言模型，我无法编写实际的程序。不过，我可以提供一个简单的文件管理系统的伪代码，希望能够帮助你了解其基本架构和功能。

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

#define MAX_FILENAME_LEN 100
#define MAX_FILE_NUM 100

struct file {
    char filename[MAX_FILENAME_LEN];
    int size;
    char* content;
};

struct file files[MAX_FILE_NUM];
int file_num = 0;

void create_file(char* filename) {
    if (file_num >= MAX_FILE_NUM) {
        printf("Failed to create file: too many files exist.\n");
        return;
    }
    for (int i = 0; i < file_num; i++) {
        if (strcmp(files[i].filename, filename) == 0) {
            printf("Failed to create file: file with the same name already exists.\n");
            return;
        }
    }
    struct file new_file;
    strcpy(new_file.filename, filename);
    new_file.size = 0;
    new_file.content = NULL;
    files[file_num] = new_file;
    file_num++;
    printf("File created successfully.\n");
}

void delete_file(char* filename) {
    int file_index = -1;
    for (int i = 0; i < file_num; i++) {
        if (strcmp(files[i].filename, filename) == 0) {
            file_index = i;
            break;
        }
    }
    if (file_index == -1) {
        printf("Failed to delete file: file not found.\n");
        return;
    }
    free(files[file_index].content);
    for (int i = file_index; i < file_num - 1; i++) {
        files[i] = files[i+1];
    }
    file_num--;
    printf("File deleted successfully.\n");
}

void read_file(char* filename) {
    int file_index = -1;
    for (int i = 0; i < file_num; i++) {
        if (strcmp(files[i].filename, filename) == 0) {
            file_index = i;
            break;
        }
    }
    if (file_index == -1) {
        printf("Failed to read file: file not found.\n");
        return;
    }
    printf("File content:\n%s\n", files[file_index].content);
}

void write_file(char* filename, char* content) {
    int file_index = -1;
    for (int i = 0; i < file_num; i++) {
        if (strcmp(files[i].filename, filename) == 0) {
            file_index = i;
            break;
        }
    }
    if (file_index == -1) {
        printf("Failed to write file: file not found.\n");
        return;
    }
    if (files[file_index].content != NULL) {
        free(files[file_index].content);
    }
    int content_len = strlen(content);
    files[file_index].content = (char*) malloc(sizeof(char) * (content_len+1));
    strcpy(files[file_index].content, content);
    files[file_index].size = content_len;
    printf("File written successfully.\n");
}

int main() {
    while (1) {
        printf("Please enter the command: ");
        char command[10];
        scanf("%s", command);
        if (strcmp(command, "create") == 0) {
            char filename[MAX_FILENAME_LEN];
            scanf("%s", filename);
            create_file(filename);
        } else if (strcmp(command, "delete") == 0) {
            char filename[MAX_FILENAME_LEN];
            scanf("%s", filename);
            delete_file(filename);
        } else if (strcmp(command, "read") == 0) {
            char filename[MAX_FILENAME_LEN];
            scanf("%s", filename);
            read_file(filename);
        } else if (strcmp(command, "write") == 0) {
            char filename[MAX_FILENAME_LEN];
            char content[1000];
            scanf("%s", filename);
            getchar(); // consume the newline character
            fgets(content, 1000, stdin);
            write_file(filename, content);
        } else if (strcmp(command, "exit") == 0) {
            break;
        } else {
            printf("Invalid command. Please try again.\n");
        }
    }
    return 0;
}

这是一个简单的命令行文件管理系统，支持创建、删除、读取和写入文件。用户可以通过键盘输入命令，并根据需要提供文件名和文件内容。程序使用一个`struct`数组来存储所有文件的信息。每个文件都有一个文件名、文件大小和文件内容。在创建和写入文件时，程序会动态分配内存以存储文件内容。在删除文件时，程序会释放文件内容的内存。