5 Simple Shell Tricks to Empty Files Instantly

1. Empty file by redirecting to /dev/null

Use shell redirection to null (a non‑existent object) to clear a file’s content.

# > access.log

2. Use the built‑in ':' (true) command for redirection

The colon : is a shell built‑in equivalent to the true command; redirect its output to a file to truncate it.

# : > access.log
OR
# true > access.log

3. Clear a file with cat/cp/dd using /dev/null

The /dev/null device discards any data written to it, making it ideal for emptying files.

Using cat: # cat /dev/null > access.log Using cp: # cp /dev/null access.log Using dd (where if is input file and of is output file):

# dd if=/dev/null of=access.log

4. Empty a file with the echo command

Redirect an empty string or nothing from echo to the file.

# echo "" > access.log
OR
# echo > access.log

To avoid a trailing newline, use the -n flag:

# echo -n "" > access.log

5. Use the truncate command

The truncate command resizes a file; with -s 0 it reduces the file to zero bytes, effectively clearing it.

# truncate -s 0 access.log