On Windows, ignore all variables that start with "=" when building an
environment variables map for stack.
For MS-DOS compatibility cmd.exe can set some special environment
variables that start with a "=" characters, which breaks the general
assumption that the first encountered "=" separates a variable name from
variable value and causes trouble when parsing.
These variables don't seem to be documented anywhere, but they are
described by some third-party sources and confirmed empirically on my
Windows installation.
Useful sources:
https://devblogs.microsoft.com/oldnewthing/20100506-00/?p=14133
https://ss64.com/nt/syntax-variables.html
Known variables:
- `=ExitCode` stores the exit code returned by external command (in hex
format)
- `=ExitCodeAscii` - same as above, except the value is the ASCII
representation of the code (so exit code 65 (0x41) becomes 'A').
- `=::=::\` and friends - store drive specific working directory.
There is one env variable for each separate drive letter that was
accessed in the shell session and stores the working directory for that
specific drive.
The general format for these is:
`=<DRIVE_LETTER>:=<CWD>` (key=`=<DRIVE_LETTER>:`, value=`<CWD>`)
where <CWD> is a working directory for the drive that is assigned to
the letter <DRIVE_LETTER>
A couple of examples:
`=C:=C:\some\dir` (key: `=C:`, value: `C:\some\dir`)
`=D:=D:\some\other\dir` (key: `=C:`, value: `C:\some\dir`)
`=Z:=Z:\` (key: `=Z:`, value: `Z:\`)
`=::=::\` is the one that seems to be always set and I'm not exactly
sure what this one is for (what's drive `::`?). Others are set as
soon as you CD to a path on some drive. Considering that you start a
cmd.exe also has some working directory, there are 2 of these on start.
All these variables can be safely ignored because they can't be
deliberately set by the user, their meaning is only relevant to the
cmd.exe session and they're all are related to the MS-DOS/Batch feature
that are irrelevant for us.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
(cherry picked from commit a47058bbd5)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Docker CLI
About
This repository is the home of the cli used in the Docker CE and Docker EE products.
Development
docker/cli is developed using Docker.
Build CLI from source:
docker buildx bake
Build binaries for all supported platforms:
docker buildx bake cross
Build for a specific platform:
docker buildx bake --set binary.platform=linux/arm64
Build dynamic binary for glibc or musl:
USE_GLIBC=1 docker buildx bake dynbinary
Run all linting:
docker buildx bake lint shellcheck
Run test:
docker buildx bake test
List all the available targets:
make help
In-container development environment
Start an interactive development environment:
make -f docker.Makefile shell
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docker/cli is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.