readwrite_sample.c

/* * Copyright (c) 2006-2018, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * *//* * 代码清单：文件读写例子 * * 这个例子演示了如何读写一个文件。 */#include <rtthread.h>#include <dfs_posix.h> /* 当需要使用文件操作时，需要包含这个头文件 */static void readwrite_sample(void){ int fd, size; char s[] = "RT-Thread Programmer!", buffer[80]; rt_kprintf("Write string %s to test.txt.\n", s); /* 以创建和读写模式打开 /text.txt 文件，如果该文件不存在则创建该文件*/ fd = open("/text.txt", O_WRONLY | O_CREAT); if (fd >= 0) { write(fd, s, sizeof(s)); close(fd); rt_kprintf("Write done.\n"); } /* 以只读模式打开 /text.txt 文件 */ fd = open("/text.txt", O_RDONLY); if (fd >= 0) { size = read(fd, buffer, sizeof(buffer)); close(fd); rt_kprintf("Read from file test.txt : %s \n", buffer); if (size < 0) return ; }}/* 导出到 msh 命令列表中 */MSH_CMD_EXPORT(readwrite_sample, readwrite sample);