Results for “command substitution”
Small, practical examples. Search by task or narrow things down below.
List running processes
Display process IDs, parent process IDs, and command names for all visible processes.
process✓ Tested
Load environment variables from a file
Docker / Compose: An env file supplies one KEY=value assignment per line.
Docker / Compose✓ Tested
Load service variables from an env file
Docker / Compose: env_file supplies runtime environment values.
Docker / Compose✓ Tested
Make a Compose service’s filesystem read-only
Docker / Compose: Make a Compose service’s filesystem read-only in a small Compose file.
Docker / Compose✓ Tested
Mount a host directory read-only
Expose existing files without allowing the container to change them.
bind mount✓ Tested
Mount a local input directory with long syntax
Docker / Compose: Long mount syntax makes the bind type and read-only intent explicit.
Docker / Compose✓ Tested
Override an env-file value explicitly
Docker / Compose: The environment section takes precedence over env_file.
Docker / Compose✓ Tested
Override an image’s entrypoint at runtime
Docker / Compose: An explicit entrypoint replaces the image entrypoint for this invocation.
Docker / Compose✓ Tested
Override the image entrypoint in Compose
Docker / Compose: entrypoint and command combine as executable and arguments.
Docker / Compose✓ Tested
Override the process working directory
Docker / Compose: The workdir option sets the directory for the container command.
Docker / Compose✓ Tested
Pass a named configuration value
Docker / Compose: Pass a named configuration value using a locally available Ubuntu image.
Docker / Compose✓ Tested
Pass an environment variable
Supply configuration without changing an image.
environment✓ Tested