split — Split a file

Linux / Basic Linux commands / split.html

Splits a large file into pieces by size or line count.

Basic Information

What is this command?

split divides an input file into pieces named xaa, xab and so on, by line count (-l) or byte size (-b). The pieces can be concatenated back with cat.

Use -d for numeric suffixes, -a for suffix length and --additional-suffix for extensions. It is commonly used to cut logs into transfer-friendly chunks.

What problems does it solve?

• Cutting large logs into transferable chunks
• Splitting input for parallel processing
• Meeting attachment size limits
• Reassembling pieces into the original file

Key features

Split by size

The -b option sets a byte size.

• When to use: Cutting files for transfer
• What you get: Pieces have a predictable size.
• Limitations: Pieces may split in the middle of a line.

Split by lines

The -l option sets a line count.

• When to use: Dividing text into logical blocks
• What you get: Line boundaries stay intact.
• Limitations: Piece sizes vary.

Naming

-d, -a and --additional-suffix control names.

• When to use: When later scripts depend on names
• What you get: Sorting and extensions stay consistent.
• Limitations: Existing files may be overwritten.

Installation and usage

Check whether it is installed

split --version

sudo apt install coreutils # Debian/Ubuntu sudo dnf install coreutils # Fedora

Real-world examples

Split by lines

Split every 1000 lines.

split -l 1000 app.log part-

Split by size

Split into 10MB pieces.

split -b 10M backup.tar.gz backup-

Reassemble

Concatenate pieces in order.

cat part-* > app.log