Add Process.capture
#16630
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Add Process.capture
#16630
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ysbaddaden
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This is a safer alternative to the command operator (or backtick operator) with no need for a shell intermediary and that raises when the command failed (non successful exit code) so we don't have to check the process status (but can do so with `$!`).
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Prefer explicit and safer calls to `Process.capture` and `Process.new`.
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Introduces the
Process.capturemethod that executes a command, captures its standard output, and returns it or raises an exception when the command fails (unsuccessful exit status).The method provides a safer replacement to the command operator (aka backticks) that has the following issues:
requires the command be executed in a shell, which in turn requires manual escapes and is prone to command injection;
doesn't check the exit status... while callers don't check it either, and errors get unnoticed.
The method is kept simple on purpose: it expects a command to always succeed (happy path) and to print to its standard output. Anything else (capture output + error, merge error -> output, act on error status) are better handled by
.newand.run.Example:
NOTE: please discuss the design in #7171.
This draft PR also provides a commit that refactors the compiler/std specs to replace all usages of the command operator and
shell: truearg, so we can evaluate the benefits of the change. It shall indeed be extracted into a follow-up PR.Closes #7171.
Related to #16614.