column

Additional Notes

column formats input into aligned, easy-to-read columns. It is especially useful for turning delimiter-separated output (such as mount or a CSV) into a tidy table.

By default it fills columns down each column; the -t (table) mode aligns by a separator and spreads columns across the page.

Syntax

column [options] [file ...]

Parameters

• options: Flags that change the layout.
• file: File to read; if omitted, reads standard input.

Common Options

• -t, --table: Create a table by detecting column separators.
• -s SEP, --separator SEP: Use a specific column separator.
• -o SEP, --output-separator SEP: Set the separator between output columns.
• -x: Fill rows across instead of down columns.
• -n: Do not merge multiple adjacent separators.
• -e: Do not ignore empty lines.
• -c WIDTH: Format for a given display width.
• -L LEVELS: For -t, how many separators to trust per line.

Examples

mount | column -t

Turn mount output into an aligned, readable table.

column -t -s, data.csv

Format a comma-separated CSV into aligned columns.

column -t -s: -o " | " /etc/passwd

Align /etc/passwd fields, separating output with | .

ls -l | column -x

List entries filled across rows instead of down columns.

column -t -s, -n report.csv

Treat repeated commas as separate empty fields.

Practical Notes

• -t is the most useful mode; pair it with -s for non-whitespace delimiters.
• mount | column -t is a quick way to read mount points.
• Use -o to choose how output columns are visually separated.
• When columns look misaligned, check that every line has the same number of separators.