RIOT/examples/filesystem/main.c

/*
 * Copyright (C) 2018 OTA keys S.A.
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @ingroup     examples
 * @{
 *
 * @file
 * @brief       File system usage example application
 *
 * @author      Vincent Dupont <vincent@otakeys.com>
 *
 * @}
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

#include "shell.h"

static int _cat(int argc, char **argv)
{
    if (argc < 2) {
        printf("Usage: %s <file>\n", argv[0]);
        return 1;
    }
    /* With newlib or picolibc, low-level syscalls are plugged to RIOT vfs
     * on native, open/read/write/close/... are plugged to RIOT vfs */
#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
    FILE *f = fopen(argv[1], "r");
    if (f == NULL) {
        printf("file %s does not exist\n", argv[1]);
        return 1;
    }
    char c;
    while (fread(&c, 1, 1, f) != 0) {
        putchar(c);
    }
    fclose(f);
#else
    int fd = open(argv[1], O_RDONLY);
    if (fd < 0) {
        printf("file %s does not exist\n", argv[1]);
        return 1;
    }
    char c;
    while (read(fd, &c, 1) != 0) {
        putchar(c);
    }
    close(fd);
#endif
    fflush(stdout);
    return 0;
}

static int _tee(int argc, char **argv)
{
    if (argc != 3) {
        printf("Usage: %s <file> <str>\n", argv[0]);
        return 1;
    }

#if defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)
    FILE *f = fopen(argv[1], "w+");
    if (f == NULL) {
        printf("error while trying to create %s\n", argv[1]);
        return 1;
    }
    if (fwrite(argv[2], 1, strlen(argv[2]), f) != strlen(argv[2])) {
        puts("Error while writing");
    }
    fclose(f);
#else
    int fd = open(argv[1], O_RDWR | O_CREAT, 00777);
    if (fd < 0) {
        printf("error while trying to create %s\n", argv[1]);
        return 1;
    }
    if (write(fd, argv[2], strlen(argv[2])) != (ssize_t)strlen(argv[2])) {
        puts("Error while writing");
    }
    close(fd);
#endif
    return 0;
}

static const shell_command_t shell_commands[] = {
    { "cat", "print the content of a file", _cat },
    { "tee", "write a string in a file", _tee },
    { NULL, NULL, NULL }
};

/* constfs example */
#include "fs/constfs.h"

#define HELLO_WORLD_CONTENT "Hello World!\n"
#define HELLO_RIOT_CONTENT  "Hello RIOT!\n"

/* this defines two const files in the constfs */
static constfs_file_t constfs_files[] = {
    {
        .path = "/hello-world",
        .size = sizeof(HELLO_WORLD_CONTENT),
        .data = (const uint8_t *)HELLO_WORLD_CONTENT,
    },
    {
        .path = "/hello-riot",
        .size = sizeof(HELLO_RIOT_CONTENT),
        .data = (const uint8_t *)HELLO_RIOT_CONTENT,
    }
};

/* this is the constfs specific descriptor */
static constfs_t constfs_desc = {
    .nfiles = ARRAY_SIZE(constfs_files),
    .files = constfs_files,
};

/* constfs mount point, as for previous example, it needs a file system driver,
 * a mount point and private_data as a pointer to the constfs descriptor */
static vfs_mount_t const_mount = {
    .fs = &constfs_file_system,
    .mount_point = "/const",
    .private_data = &constfs_desc,
};

int main(void)
{
    int res = vfs_mount(&const_mount);
    if (res < 0) {
        puts("Error while mounting constfs");
    }
    else {
        puts("constfs mounted successfully");
    }

    char line_buf[SHELL_DEFAULT_BUFSIZE];
    shell_run(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);

    return 0;
}