---
name: "uniq"
section: "1plan9"
platform: "linux"
package: "9base"
version: "1:6-14"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/uniq/1plan9"
---

# uniq(1plan9)

report repeated lines in a file

## NAME

uniq - report repeated lines in a file

## SYNOPSIS

**uniq** \[ **-udc** \[ **+-***num* \] \] \[ *file* \]

## DESCRIPTION

*Uniq* copies the input *file*, or the standard input, to the standard output, comparing adjacent lines. In the normal case, the second and succeeding copies of repeated lines are removed. Repeated lines must be adjacent in order to be found.

- **-u**

  Print unique lines.

- **-d**

  Print (one copy of) duplicated lines.

- **-c**

  Prefix a repetition count and a tab to each output line. Implies **-u** and **-d**.

- **-***num*

  The first *num* fields together with any blanks before each are ignored. A field is defined as a string of non-space, non-tab characters separated by tabs and spaces from its neighbors.

- **+***num*

  The first *num* characters are ignored. Fields are skipped before characters.

## SOURCE

**/src/cmd/uniq.c**

## SEE ALSO

[*sort*(1)](/sort/1.md)

## BUGS

Field selection and comparison should be compatible with  [*sort*(1)](/sort/1.md).