400.txt -

Type the following command and press : cat *.txt > combined_files.txt

Error in opening existing file in SdFat library? - Arduino Forum

Navigate to your folder using cd (e.g., cd Desktop/my_folder ). 400.txt

For more complex tasks—like changing font sizes or specific formatting across 400 files—tools like findandreplace.io or Batch Word Replace are often recommended.

Most systems will merge the files alphabetically. If you need them in a specific sequence (e.g., 1 to 400), ensure they are named with leading zeros (e.g., 001.txt , 002.txt ). Type the following command and press : cat *

Result: The cat (concatenate) command merges the contents sequentially into the new file. 🛠️ Important Tips

Hold and Right-Click in the empty space, then select Open PowerShell window here or Open Command Prompt here . Most systems will merge the files alphabetically

If your files don't end with a "new line" character, the last line of one file and the first line of the next might stick together.