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Which comment style should I use dans batch files?

ayi

Which comment style should I use in batch files?

ayi_2

tl;dr: <code>REM</code> is the documented and supported way to embed comments in batch files.
<code>::</code> is essentially a blank label that can never be jumped to, whereas <code>REM</code> is an actual command that just does nothing. In neither case (at least on Windows 7) does the presence of redirection operators cause a problem.
However, <code>::</code> is known to misbehave in blocks under certain circumstances, being parsed not as a label but as some sort of drive letter. I’m a little fuzzy on where exactly but that alone is enough to make me use <code>REM</code> exclusively. It’s the documented and supported way to embed comments in batch files whereas <code>::</code> is merely an artifact of a particular implementation.
Here is an example where <code>::</code> produces a problem in a <code>FOR</code> loop.
This example will not work in a file called <code>test.bat</code> on your desktop:
<pre><code class="lang-auto">@echo off
for /F "delims=" %%A in ('type C:\Users\%username%\Desktop\test.bat') do (
::echo hello>C:\Users\%username%\Desktop\text.txt
)
pause

</code></pre>
While this example will work as a comment correctly:
<pre><code class="lang-auto">@echo off
for /F "delims=" %%A in ('type C:\Users\%username%\Desktop\test.bat') do (
REM echo hello>C:\Users\%username%\Desktop\text.txt
)
pause

</code></pre>
The problem appears to be when trying to redirect output into a file. My best guess is that it is interpreting <code>::</code> as an escaped label called <code>:echo</code>.