---
name: "astheader"
section: "1"
platform: "linux"
package: "gnuastro"
version: "0.2.33-1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/astheader"
---

# astheader(1)

view and manipulate FITS headers

## NAME

Header - view and manipulate FITS headers

## SYNOPSIS

**astheader** \[*OPTION*...\] *ASTRdata*

## DESCRIPTION

Header is part of GNU Astronomy Utilities 0.2.33-8a3b. Header print the header information in any astronomical data fileheader. It can also manipulate (add, remove or modify) any of the existing keywords in a data header.

For more information, please run any of the following commands. They will respectively show you the \`Invoking Header' subsection, the complete \`Header' section, or the full GNU Astronomy Utilities manual. In particular the first contains a very complete explanation of each option.

-

  info astheader

-

  info Header

-

  info gnuastro

If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run:

-

  info help-gnuastro

Header options:

-

  Input:

- **-h**, **--hdu**=*STR*

  Extension name or number of input data.

-

  Output:

- **-a**, **--asis**=*STR*

  Write the argument string as is into the header.

- **-c**, **--comment**=*STR*

  Add COMMENT keyword, any length is ok.

- **-d**, **--delete**=*STR*

  Delete a keyword from the header.

- **-D**, **--dontdelete**

  Don't delete output if it exists.

- **-H**, **--history**=*STR*

  Add HISTORY keyword, any length is ok.

- **-K**, **--keepinputdir**

  Do not remove input's dir info for output.

- **-o**, **--output**=*STR*

  Output file or directory name.

- **-r**, **--rename**=*STR*

  Rename keyword, keeping value and comments.

- **-t**, **--date**

  Set the DATE keyword to the current time.

- **-u**, **--update**=*STR*

  Update a keyword value or comments.

- **-w**, **--write**=*STR*

  Write a keyword (with value, comments and units).

-

  Operating modes:

- \-?, **--help**

  give this help list

- **--cite**

  BibTeX citation for Header.

- **--nolog**

  No log file for programs which make one.

- **-N**, **--numthreads**=*INT*

  Number of CPU threads to use.

- **--onlydirconf**

  Only read current directory configuration file.

- **--onlyversion**=*STR*

  Only run if the program version is this.

- **-P**, **--printparams**

  Print parameter values to be used and abort.

- **-q**, **--quiet**

  Only report errors, remain quiet about steps.

- **-Q**, **--quitonerror**

  Quit if there is an error on any action.

- **-S**, **--setdirconf**

  Set default values for this directory and abort.

- **--usage**

  give a short usage message

- **-U**, **--setusrconf**

  Set default values for this user and abort.

- **-V**, **--version**

  print program version

Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/

## AUTHOR

Written by Mohammad Akhlaghi

## REPORTING BUGS

Report bugs to bug-gnuastro@gnu.org.

## COPYRIGHT

Copyright © 2015-2016, Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.\
 This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

## SEE ALSO

The full documentation for **Header** is maintained as a Texinfo manual.  If the **info** and **Header** programs are properly installed at your site, the command

-

  **info Header**

should give you access to the complete manual.