esp-idf/examples/storage/spiffsgen/main/spiffsgen_example_main.c

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/* SPIFFS Image Generation on Build Example
*
* SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense or CC0-1.0
*/
#include <stdio.h>
#include <string.h>
#include <sys/unistd.h>
#include <sys/stat.h>
#include "esp_err.h"
#include "esp_log.h"
#include "esp_spiffs.h"
#include "mbedtls/md5.h"
static const char *TAG = "example";
static void read_hello_txt(void)
{
ESP_LOGI(TAG, "Reading hello.txt");
// Open for reading hello.txt
FILE* f = fopen("/spiffs/hello.txt", "r");
if (f == NULL) {
ESP_LOGE(TAG, "Failed to open hello.txt");
return;
}
char buf[64];
memset(buf, 0, sizeof(buf));
fread(buf, 1, sizeof(buf), f);
fclose(f);
// Display the read contents from the file
ESP_LOGI(TAG, "Read from hello.txt: %s", buf);
}
static void compute_alice_txt_md5(void)
{
ESP_LOGI(TAG, "Computing alice.txt MD5 hash");
// The file alice.txt lives under a subdirectory, though SPIFFS itself is flat
FILE* f = fopen("/spiffs/sub/alice.txt", "r");
if (f == NULL) {
ESP_LOGE(TAG, "Failed to open alice.txt");
return;
}
// Read file and compute the digest chunk by chunk
#define MD5_MAX_LEN 16
char buf[64];
mbedtls_md5_context ctx;
unsigned char digest[MD5_MAX_LEN];
mbedtls_md5_init(&ctx);
mbedtls_md5_starts(&ctx);
size_t read;
do {
read = fread((void*) buf, 1, sizeof(buf), f);
mbedtls_md5_update(&ctx, (unsigned const char*) buf, read);
} while(read == sizeof(buf));
mbedtls_md5_finish(&ctx, digest);
// Create a string of the digest
char digest_str[MD5_MAX_LEN * 2];
for (int i = 0; i < MD5_MAX_LEN; i++) {
sprintf(&digest_str[i * 2], "%02x", (unsigned int)digest[i]);
}
// For reference, MD5 should be deeb71f585cbb3ae5f7976d5127faf2a
ESP_LOGI(TAG, "Computed MD5 hash of alice.txt: %s", digest_str);
fclose(f);
}
void app_main(void)
{
ESP_LOGI(TAG, "Initializing SPIFFS");
esp_vfs_spiffs_conf_t conf = {
.base_path = "/spiffs",
.partition_label = NULL,
.max_files = 5,
.format_if_mount_failed = false
};
// Use settings defined above to initialize and mount SPIFFS filesystem.
// Note: esp_vfs_spiffs_register is an all-in-one convenience function.
esp_err_t ret = esp_vfs_spiffs_register(&conf);
if (ret != ESP_OK) {
if (ret == ESP_FAIL) {
ESP_LOGE(TAG, "Failed to mount or format filesystem");
} else if (ret == ESP_ERR_NOT_FOUND) {
ESP_LOGE(TAG, "Failed to find SPIFFS partition");
} else {
ESP_LOGE(TAG, "Failed to initialize SPIFFS (%s)", esp_err_to_name(ret));
}
return;
}
size_t total = 0, used = 0;
ret = esp_spiffs_info(NULL, &total, &used);
if (ret != ESP_OK) {
ESP_LOGE(TAG, "Failed to get SPIFFS partition information (%s)", esp_err_to_name(ret));
} else {
ESP_LOGI(TAG, "Partition size: total: %d, used: %d", total, used);
}
/* The following calls demonstrate reading files from the generated SPIFFS
* image. The images should contain the same files and contents as the spiffs_image directory.
*/
// Read and display the contents of a small text file (hello.txt)
read_hello_txt();
// Compute and display the MD5 hash of a large text file (alice.txt)
compute_alice_txt_md5();
// All done, unmount partition and disable SPIFFS
esp_vfs_spiffs_unregister(NULL);
ESP_LOGI(TAG, "SPIFFS unmounted");
}