fs_read

int fs_read(struct fs_file *file, uint32_t len, void *out_data, uint32_t *out_len)

Reads data from the specified file. If more data is requested than remains in the file, all available data is retrieved and a success code is returned.

Arguments

Argument	Description
file	Pointer to the the file to read from
len	The number of bytes to attempt to read
out_data	The destination buffer to read into
out_len	On success, the number of bytes actually read gets written here. Pass null if you don't care.

Returned values

• 0 on success
• FS error code on failure

Header file

#include "fs/fs.h"

Example

The below code opens the file /settings/config.txt for reading, reads some data, and then closes the file.

int
read_config(void)
{
    struct fs_file *file;
    uint32_t bytes_read;
    uint8_t buf[16];
    int rc;

    /* Open the file for reading. */
    rc = fs_open("/settings/config.txt", FS_ACCESS_READ, &file);
    if (rc != 0) {
        return -1;
    }

    /* Read up to 16 bytes from the file. */
    rc = fs_read(file, sizeof buf, buf, &bytes_read);
    if (rc == 0) {
        /* buf now contains up to 16 bytes of file data. */
        console_printf("read %u bytes\n", bytes_read)
    }

    /* Close the file. */
    fs_close(file);

    return rc == 0 ? 0 : -1;
}