fork(1) download
copy 
  1. #include <stdio.h>
  2. #include <stdint.h>
  3. #include <string.h>
  4.  
  5. // Function to copy data from a const char* to a uint8_t* buffer
  6. // buff[0] = data_length, buff[1..length] = actual data
  7. void copy_data_to_buffer(const char *data, uint8_t *buff, size_t buff_size) {
  8.     // Calculate the length of the input data
  9.     size_t data_length = strlen(data);
  10.  
  11.     // Ensure the buffer is large enough to hold the length byte + data + null terminator (if needed)
  12.     if (data_length + 1 > buff_size) {
  13.         printf("Error: Buffer is too small to hold the data and length.\n");
  14.         return;
  15.     }
  16.  
  17.     // Store the length in buff[0]
  18.     buff[0] = (uint8_t)data_length;
  19.  
  20.     // Copy the data into buff[1..length]
  21.     memcpy(&buff[1], data, data_length);
  22.  
  23.     // Optionally, null-terminate the buffer (if needed)
  24.     buff[5 + 1] = '\0';
  25. }
  26.  
  27. int main() {
  28.     const char *data = "Hello";  // Example input data
  29.     uint8_t buff[6];  // Buffer to hold the length and data
  30.  
  31.     // Copy the data into the buffer
  32.     copy_data_to_buffer(data, buff, sizeof(buff));
  33.  
  34.     // Print the length and copied data
  35.     printf("sizeof(buff)=%d\n",sizeof(data));
  36.     printf("Data length: %d\n", buff[6]);
  37.     printf("Copied data: %s\n", (char *)&buff[1]);
  38.  
  39.     return 0;
  40. }
Success #stdin #stdout 0s 5284KB
comments ()
stdin
copy 
Standard input is empty
stdout
copy 
sizeof(buff)=8
Data length: 0
Copied data: Hello
https://ideone.com/lcmZiF
language:
C (gcc 8.3)
created:
38 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!