table

README

since debian stable's version of column(1) doesn't handle successive delimiters

$ go install go.senan.xyz/table/cmd/table@master

$ printf '%s\t%s\t%s\n' '' b c aaaa b c a bbbbbb c '' '' c | table
     b      c
aaaa b      c
a    bbbbbb c
            c

$ printf '%s\t%s\t%s\n' '' b c aaaa b c a bbbbbb c '' '' c | table ' | '
     | b      | c
aaaa | b      | c
a    | bbbbbb | c
     |        | c

# works for streams with a flush interval
$ tail -f logs | pick-cols | table " : " 3
2023 : event one   : event param           : 53f1a74226358c8c7
2023 : event two   : event name is longer  : 53f1a74226358c8c7
2023 : event three : event                 : 53f1a74226358c8c7
2023 : event longer one   : event longer param           : 53f1a74226358c8c7
2023 : event longer two   : event longer name is longer  : 53f1a74226358c8c7
2023 : event longer three : event longer                 : 53f1a74226358c8c7

Documentation

Overview

Package table provides a Writer that formats tab-separated data into aligned columns. Column widths account for ANSI escape sequences and grapheme cluster widths (via uniseg).

Index

• func FormatLines(lines []string)
• func FormatReader(r io.Reader) ([]string, error)
• type RowError
  • func (re *RowError) Error() string
• type Writer
  • func New(out io.Writer) *Writer
  • func (w *Writer) Flush() error
  • func (w *Writer) SetFormat(pre, sep, suff string)
  • func (w *Writer) Write(p []byte) (int, error)

Functions

func FormatLines

func FormatLines(lines []string)

FormatLines formats the provided lines in-place. Lines with a mismatched column count (relative to the first line) are ignored, matching the behavior of the original code (they remain unchanged).

func FormatReader

func FormatReader(r io.Reader) ([]string, error)

FormatReader reads tab-separated data and returns formatted lines in one pass

Types

type RowError

type RowError struct {
	Want, Got int
	Line      int
}

func (*RowError) Error

func (re *RowError) Error() string

type Writer

type Writer struct {
	// contains filtered or unexported fields
}

func New

func New(out io.Writer) *Writer

New constructs a new Writer that will emit formatted rows to out on Flush.

func (*Writer) Flush

func (w *Writer) Flush() error

Flush formats all buffered rows and writes them to out, then resets rows/widths. Returns the first error encountered during Write/addLine or any write error.

func (*Writer) SetFormat

func (w *Writer) SetFormat(pre, sep, suff string)

SetFormat controls formatting for the output including prefix, column separator, and suffix.

func (*Writer) Write

func (w *Writer) Write(p []byte) (int, error)

Write ingests bytes, splitting on '\n' (handles optional trailing '\r'). Parsed lines are buffered; call Flush to write formatted output to out. Column-count errors are recorded and surfaced on Flush; subsequent lines are still processed.