apptainer-run-help

Display the run-help for a container

$ apptainer run-help [container.sif]

$ apptainer run-help docker://[image:tag]

$ apptainer run-help library://[user/collection/image:tag]

$ apptainer run-help oci-archive://[path/to/archive.tar]

apptainer run-help [options] container

apptainer run-help displays help text embedded within an Apptainer/Singularity container. This help information is defined during container build time using the %help section in a definition file.
Container authors use the %help section to document how to use their container, including expected arguments, required bind mounts, environment variables, and example commands. This provides users with container-specific usage information without needing external documentation.
When called on a container without a help section, the command returns with no output. The help text is stored in the container's metadata and does not affect the container's runtime size significantly.
This command is particularly useful in HPC environments where users may encounter unfamiliar containers and need quick usage guidance. It complements apptainer inspect which shows technical metadata rather than user-facing documentation.

container

Path to a SIF file or URI to a container image (docker://, library://, oci-archive://).

Display help for the run-help command.

Only displays help if the container author included a %help section during build. Returns nothing (not an error) if no help is defined. Cannot add help to an existing container without rebuilding it.

The run-help feature has been part of Singularity/Apptainer since early versions, providing a standardized way for container authors to document container usage. The command was retained when Singularity became Apptainer under the Linux Foundation in 2021.

apptainer(1), apptainer-run(1), apptainer-inspect(1), apptainer-build(1)