columns

A command-line tool for formatting text into readable columns with automatic wrapping.

Description

columns takes tabular text input and formats it nicely within a specified width. It can auto-detect columns from whitespace or use explicit separators. Long text wraps within columns instead of getting truncated, so you can actually read those annoyingly wide command outputs.

Useful for making wide terminal output readable, formatting tables, or just making data look nice.

Usage

Basic usage:

# Auto-detect columns and use terminal width
columns input.txt

# Specify width
columns --width 100 input.txt

# Use a specific separator (tab, comma, semicolon, etc.)
columns -s $'\t' data.tsv
columns -s ',' data.csv

# Read from stdin
docker ps | columns --width 120

Examples

Auto-detecting columns from whitespace

The tool looks for runs of 2+ spaces (configurable with --column-spacing) to detect column boundaries.

# Terminal with 160 width [looks nice]
$ docker ps
CONTAINER ID   IMAGE                       COMMAND                  CREATED       STATUS       PORTS                                           NAMES
647650d0a017   ubuntu                      "/bin/bash"              3 hours ago   Up 3 hours   0.0.0.0:32768->1090/tcp, [::]:32768->1090/tcp   stupefied_bardeen
ca451888695b   vsc-columns-86a01c23e-uid   "/bin/sh -c 'echo Co…"   7 days ago    Up 8 hours                                                   ecstatic_napier


# Terminal with 110 width [wraps awkwardly]
$ docker ps
CONTAINER ID   IMAGE                       COMMAND                  CREATED       STATUS       PORTS          
                                 NAMES
647650d0a017   ubuntu                      "/bin/bash"              3 hours ago   Up 3 hours   0.0.0.0:32768->
1090/tcp, [::]:32768->1090/tcp   stupefied_bardeen
ca451888695b   vsc-columns-86a01c23e-uid   "/bin/sh -c 'echo Co…"   7 days ago    Up 8 hours                
                                   ecstatic_napier


# Terminal with 110 width | columns [wraps better]
$ docker ps | columns
CONTAINER ID  IMAGE                      COMMAND       CREATED   STATUS   PORTS              NAMES            
647650d0a017  ubuntu                     "/bin/bash"   3 hours   Up 3     0.0.0.0:           stupefied_bardeen
                                                       ago       hours    32768->1090/tcp,                    
                                                                          [::]:                               
                                                                          32768->1090/tcp                     
ca451888695b  vsc-columns-86a01c23e-uid  "/bin/sh -c   7 days    Up 8                        ecstatic_napier  
                                         'echo Co…"    ago       hours                                        

Formatting tab-separated data

# Data (note: Separated with tabs, not spaces)
$ cat data.tsv
Name	Age	Department	Salary	Location
John Smith	32	Engineering	95000	San Francisco
Maria Garcia	28	Marketing	72000	New York
David Lee	45	Sales	88000	Chicago
Sarah Johnson	36	Engineering	105000	Seattle
Michael Brown	41	Finance	98000	Boston


# Formatted
$ columns -s $'\t' data.tsv
Name            Age  Department   Salary  Location     
John Smith      32   Engineering  95000   San Francisco
Maria Garcia    28   Marketing    72000   New York     
David Lee       45   Sales        88000   Chicago      
Sarah Johnson   36   Engineering  105000  Seattle      
Michael Brown   41   Finance      98000   Boston       

Installation

Build from source:

cargo build --release

The binary will be at target/release/columns.

Licence

BSD-3-Clause