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[bug #28126] bug with Windows interface: echo. in command only works whe
[bug #28126] bug with Windows interface: echo. in command only works when redirected
Mon, 30 Nov 2009 05:03:43 +0000
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Summary: bug with Windows interface: echo. in command only
works when redirected
Submitted by: None
Submitted on: Mon 30 Nov 2009 05:03:42 AM UTC
Severity: 3 - Normal
Item Group: Bug
Assigned to: None
Discussion Lock: Any
Component Version: 3.81
Operating System: None
Fixed Release: None
Triage Status: None
Hello, I asked for help on this issue (with GNU make on Windows) on the
help-make list, and Paul Smith says, this is a bug. I am using WinXP Pro,
SP3. Here is an SSCCE:
However, this one:
process_begin: CreateProcess(NULL, echo., ...) failed.
make (e=2): The system cannot find the file specified.
make: *** [foobar] Error 2
Here's what Paul says:
I'd guess that this is due to make's fast path processing: if make can
determine that the command you're invoking does not need a shell, it won't
start one; instead it will simply try to invoke the command directly.
In this case, the command "echo." is not known to make as a command that
requires a shell, so it tries to run it directly. In reality this is not a
real command but rather a builtin command for the Windows shell (for example
command.com), so trying to invoke it directly fails.
On the other hand, when you run "echo.>foo" make sees the redirection
(">") and understands that this is not a simple command and can't be run
using the fast path, so it invokes the shell to run it and it works.
It's not in the manual because it's supposed to be invisible to the user
(that is, it's an implementation detail, not a user-visible feature, and so
not documented in the user manual). The idea is to improve performance by
avoiding an extra (and sometimes costly) shell invocation in situations where
it can be shown that the results are the same either way.
If it's visible to the user, as it is in this case, then there's a bug in the
fast path processing.
" (end of quotes from Paul)
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- [bug #28126] bug with Windows interface: echo. in command only works when redirected,