multiline commands in qx//

On Mon, 21 Jul 1997 15:50:03 EDT, Ilya Zakharevich wrote:
>In article <199707202332.TAA05144@aatma.engin.umich.edu>,
>Gurusamy Sarathy  <gsar@engin.umich.edu> wrote:
>> +the system's command shell for parsing (this is C</bin/sh -c> on Unix
>> +platforms, but varies on other platforms).  If there are none, the
>> +argument is split into words and passed directly to execvp(), which is
>> +more efficient.  Note: exec() and system() do not flush your output
>> +buffer, so you may need to set C<$|> to avoid lost output.  Examples:
>
>"If there are none" should be changed to "if command contains no shell
>metacharacters".

Here's a newer version of that doc patch.  Ignore the old one.

p5p-msgid: 199707212350.TAA18496@aatma.engin.umich.edu

1 files changed, 18 insertions, 0 deletions

diff --git a/pod/perlop.pod b/pod/perlop.pod
index 32a0827cb3..2709a9eaa2 100644
--- a/pod/perlop.pod
+++ b/pod/perlop.pod
@@ -808,6 +808,24 @@ with $/ or $INPUT_RECORD_SEPARATOR).
 
     $today = qx{ date };
 
+Note that how the string gets evaluated is entirely subject to the
+command interpreter on your system.  On most platforms, you will have
+to protect shell metacharacters if you want them treated literally.
+On some platforms (notably DOS-like ones), the shell may not be
+capable of dealing with multiline commands, so putting newlines in
+the string may not get you what you want.  You may be able to evaluate
+multiple commands in a single line by separating them with the command
+separator character, if your shell supports that (e.g. C<;> on many Unix
+shells; C<&> on the Windows NT C<cmd> shell).
+
+Beware that some command shells may place restrictions on the length
+of the command line.  You must ensure your strings don't exceed this
+limit after any necessary interpolations.  See the platform-specific
+release notes for more details about your particular environment.
+
+Also realize that using this operator frequently leads to unportable
+programs.
+
 See L<"I/O Operators"> for more discussion.
 
 =item qw/STRING/