---
name: "fitscheck"
section: "1"
platform: "linux"
package: "astropy-utils"
version: "7.0.1-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/fitscheck"
---

# fitscheck(1)

script to detect and fix FITS standards violations

## NAME

fitscheck - script to detect and fix FITS standards violations

## SYNOPSIS

**fitscheck** \[*OPTION*\]... \[*FILE*\]...

## DESCRIPTION

**fitscheck** is a command line script based on pyfits for verifying and updating the CHECKSUM and DATASUM keywords of FITS files. **itscheck** can also detect and often fix other FITS standards violations. **fitscheck** facilitates re-writing the non-standard checksums originally generated by pyfits with standard checksums which will interoperate with cfitsio.

**fitscheck** will refuse to write new checksums if the checksum keywords are missing or their values are bad.  Use **--force** to write new checksums regardless of whether or not they currently exist or pass. Use **--ignore-missing** to tolerate missing checksum keywords without comment.

## OPTIONS

- **-h**, **--help**

  Display terse usage information (help).

- **-k** \[*standard* \| *nonstandard* \| *either* \| *none*\], **--checksum**=\[*standard* \| *nonstandard* \| *either* \| *none*\]

  Choose FITS checksum mode or none. Defaults to standard.

- **-w**, **--write**

  Write out file checksums and/or FITS compliance fixes.

- **-f**, **--force**

  Do file update even if original checksum was bad.

- **-c**, **--compliance**

  Do FITS compliance checking, fix if possible.

- **-i**, **--ignore-missing**

  Ignore missing checksums.

- **-v**, **--verbose**

  Generate extra output.

## EXAMPLES

**% fitscheck --checksum either --write \*.fits**\
 Verify and update checksums, tolerating non-standard checksums, updating to standard checksum.

**% fitscheck --write --force \*.fits**\
 Write new checksums, even if existing checksums are bad or missing.

**% fitscheck --compliance \*.fits**\
 Verify standard checksums and FITS compliance without changing the files.

**% fitscheck --checksum nonstandard \*.fits**\
 Verify original nonstandard checksums only.

**% fitscheck --checksum none --compliance --write \*.fits**\
 Only check and fix compliance problems,  ignoring checksums.

**% fitscheck \*.fits**\
 Verify standard interoperable checksums.

**% fitscheck --checksum none --write \*.fits**\
 Delete checksum keywords.