Usage¶

Basic Usage¶

# Fill current directory until disk is full, then delete files
pushfill

# Fill a specific directory
pushfill /tmp

# Write to a single file
pushfill /tmp/fill.bin

# Write a specific amount then delete
pushfill /tmp --size 10G

# Write and keep the files
pushfill /tmp --size 500M --keep

Options¶

Short	Long	Description
	`path`	Directory or file to fill (default: current directory)
`-s`	`--size`	Target size to write (e.g. `10G`, `500M`, `1T`). Default: fill disk
`-k`	`--keep`	Keep generated files instead of deleting them
`-w`	`--workers`	Number of worker goroutines (default: CPU count)
`-c`	`--chunk-size`	Chunk size in MiB per write (default: 4)
`-f`	`--fat32`	Limit each file to 4 GiB (for FAT32 filesystems)
`-m`	`--max-file-size`	Maximum size per file (e.g. `2G`). Overrides `--fat32`
`-n`	`--no-colour`	Disable coloured output
`-v`	`--verbose`	Show verbose output
	`--version`	Show version and exit

Size Format¶

Sizes can be specified with the following units:

Unit	Meaning
`B`	Bytes
`K` / `KB`	Kibibytes (1024 bytes)
`M` / `MB`	Mebibytes (1024^2 bytes)
`G` / `GB`	Gibibytes (1024^3 bytes)
`T` / `TB`	Tebibytes (1024^4 bytes)

Examples: 100M, 10G, 1T, 500MB, 4096B

FAT32 Support¶

pushfill automatically detects FAT32 filesystems and limits file sizes to 4 GiB - 1 byte. You can also force this behaviour with --fat32, or set a custom per-file limit with --max-file-size.

# Auto-detected
pushfill /mnt/usb

# Explicit
pushfill /mnt/usb --fat32

# Custom limit
pushfill /mnt/usb --max-file-size 2G

Single-File Mode¶

When the path argument points to a file (rather than a directory), pushfill writes to that single file using one worker.

# Create and fill a single file
pushfill /tmp/fill.bin --size 1G

Keeping Files¶

By default, pushfill deletes all generated files after completion (or interruption). Use --keep to retain them.

pushfill /tmp --size 1G --keep

If you run pushfill again in the same directory after using --keep, it will create new files alongside the existing ones — it won't overwrite previously kept files.

Interrupting¶

Press Ctrl+C to stop pushfill gracefully. It will:

Signal all workers to stop
Display a summary of what was written
Delete generated files (unless --keep was used)

Files are always cleaned up, even on interruption.