# Failures saving a volume to path with % sign

**URL:** <https://discourse.slicer.org/t/failures-saving-a-volume-to-path-with-sign/25657>\
**Category:** Support\
**Created:** [October 12, 2022, 6:55pm UTC](https://discourse.slicer.org/t/failures-saving-a-volume-to-path-with-sign/25657 "2022-10-12T18:55:57Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [October 13, 2022, 5:04pm UTC](https://discourse.slicer.org/t/failures-saving-a-volume-to-path-with-sign/25657/6 "2022-10-13T17:04:03Z")

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MetaIO supports [One-Slice-Per-File Data Formats](https://itk.org/Wiki/ITK/MetaIO/Documentation#Reading_DICOM_and_Other_One-Slice-Per-File_Data_Formats) and it uses the `%` character to specify the slice number in the filename format string.

Due to the special meaning of the `%` character, currently [MetaIO does not allow using this chracter in the path](https://github.com/Kitware/MetaIO/blob/0b8c5284f3fe126968fd66c24639fd70b88e8788/src/metaImage.cxx#L1533). This limitation should either be clearly documented or the implementation should be made more sophisticated (to somehow differentiate the `%` that refers to per-slice filename generation from simple `%` occurrences in the path; or by allowing completely disabling this extremely rarely used one-slice-per-file feature).

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_[View the full topic](https://discourse.slicer.org/t/failures-saving-a-volume-to-path-with-sign/25657)._