---
name: "clubak"
section: "1"
platform: "linux"
package: "clustershell"
version: "1.10.1-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/clubak"
---

# clubak(1)

format output from clush/pdsh-like output and more

## NAME

clubak - format output from clush/pdsh-like output and more

## SYNOPSIS

**clubak** \[ OPTIONS \]

## DESCRIPTION

**clubak** formats text from standard input containing lines of the form "*node:output*".  It is fully backward compatible with [**dshbak**(1)](/dshbak/1.md) but provides additional features. For instance, **clubak** always displays its results sorted by node/nodeset.

You do not need to use **clubak** when using [**clush**(1)](/clush/1.md) as all output formatting features are already included in it. It is provided for other usages, like post-processing results of the form "*node:output*".

Like [**clush**(1)](/clush/1.md), **clubak** uses the *ClusterShell.MsgTree* module of the ClusterShell library (see **pydoc ClusterShell.MsgTree**).

## INVOCATION

**clubak** should be started with connected standard input.

## OPTIONS

- **--version**

  show **clubak** version number and exit

- **-b, -c, --dshbak**

  gather nodes with same output (-c and --dshbak are provided for [**dshbak**(1)](/dshbak/1.md) compatibility)

- **-B**

  same as -b; accepted for compatibility with [**clush**(1)](/clush/1.md), where -B also gathers standard error

- **-q, --quiet**

  be quiet, print essential output only (e.g. suppress the node count displayed next to gathered nodeset headers)

- **-v, --verbose**

  be verbose, print informative messages; also echo each input line to standard output prefixed by **INPUT**

- **-d, --debug**

  output more messages for debugging purpose

- **-L**

  disable header block and order output by nodes

- **-N**

  disable labeling of command output

- **-r, --regroup**

  fold nodeset using node groups

- **--axis=***RANGESET*

  for nD nodesets, fold the displayed nodeset (e.g. in gathered output headers) along provided axis only. Axes are indexed from 1 to n and can be specified here either using the rangeset syntax, e.g. '1', '1-2', '1,3', or by a single negative number meaning that the index is counted from the end. Because some nodesets may have several different dimensions, axis indices are silently truncated to fall in the allowed range. This is the per-invocation equivalent of the **fold\_axis** library default.

- **-s** *GROUPSOURCE,* **--groupsource=***GROUPSOURCE*

  optional [**groups.conf**(5)](/groups.conf/5.md) group source to use

- **--groupsconf=***FILE*

  use alternate config file for [**groups.conf**(5)](/groups.conf/5.md)

- **-G, --groupbase**

  do not display group source prefix (always *@groupname*)

- **-S** *SEPARATOR,* **--separator=***SEPARATOR*

  node / line content separator string (default: *:*)

- **-F, --fast**

  faster but memory hungry mode (preload all messages per node)

- **-T, --tree**

  message tree trace mode; switch to enable **ClusterShell.MsgTree** trace mode, all keys/nodes being kept for each message element of the tree, thus allowing special output display

- **--interpret-keys=***INTERPRET\_KEYS*

  whether to interpret keys (the field before the separator on each input line) as node sets. *INTERPRET\_KEYS* is **never**, **always** or **auto** (the default). With **never**, each key is kept as a plain string; with **always**, every key must be a valid node set; with **auto**, keys are interpreted as node sets, but if any key cannot be parsed, **clubak** silently switches to treating all keys as plain strings.

- **--color=***WHENCOLOR*

  **clubak** can use NO\_COLOR, CLICOLOR and CLICOLOR\_FORCE environment variables. **--color** command line option always takes precedence over environment variables. NO\_COLOR takes precedence over CLICOLOR\_FORCE which takes precedence over CLICOLOR. **--color** tells whether to use ANSI colors to surround node or nodeset prefix/header with escape sequences to display them in color on the terminal. *WHENCOLOR* is **never**, **always** or **auto** (which uses color if standard output refers to a terminal). Color is set to \[34m (blue foreground text) and cannot be modified.

- **--diff**

  show diff between gathered outputs

## EXIT STATUS

An exit status of zero indicates success of the **clubak** command.

## EXAMPLES

- 1\.

  **clubak** can be used to gather some recorded [**clush**(1)](/clush/1.md) results:

- **Record [clush(1)](/clush/1.md) results in a file:**

  ```
  # clush -w node[1-7] uname -r >/tmp/clush_output
  # clush -w node[32-159] uname -r >>/tmp/clush_output
  ```

- **Display file gathered results (in line-mode):**

  ```
  # clubak -bL </tmp/clush_output
  ```

- 2\.

  Another example, iterate over *node\** text files in current directory and gather characters count for all of them:

  ```
  # find -name "node*" -exec wc -c {} ; | awk '{ gsub("./","",$2); print $2": "$1 }' | clubak -bL
  node[1,3]: 7
  node2: 9
  ```

## SEE ALSO

[**cluset**(1)](/cluset/1.md), [**clush**(1)](/clush/1.md), [**nodeset**(1)](/nodeset/1.md), [**groups.conf**(5)](/groups.conf/5.md).

*https://clustershell.readthedocs.io/*

## BUG REPORTS

- **Use the following URL to submit a bug report or feedback:**

  *https://github.com/clustershell/clustershell/issues*

## AUTHOR

Stephane Thiell

## COPYRIGHT

GNU Lesser General Public License version 2.1 or later (LGPLv2.1+)