On 2012-12-08, at 17:51, "David T. Lewis" <lewis at mail.msen.com> wrote:

> On Sat, Dec 08, 2012 at 10:55:41AM -0500, David T. Lewis wrote:
>> On Sat, Dec 08, 2012 at 09:16:46AM +0100, Bert Freudenberg wrote:
>>> On 08.12.2012, at 03:10, "David T. Lewis" <lewis at mail.msen.com> wrote:
>>>> 
>>>> cmd := 'od -v -t x1 ', (Smalltalk imageName copyAfterLast: $/) asVmPathName.
>>>> pipeline := ProxyPipeline command: cmd.
>>>> data := pipeline next: 1000.
>>>> pipeline closePipes.
>>>> data inspect
>>> 
>>> Okay, that looks a lot simpler. But with the string interface I have to worry about argument escaping. That's why I wanted to use the array interface, and avoid a shell. Constructing a sanitized string from user data is very hard, and made unnecessary bybusing a non-interpreted interface.
>>> 
>>> Also, as I wrote I need to be able to set the working directory (and potentially the environment). Your example only works accidentally because you launched squeak from the image directory.
>>> 
>> 
>> This does not directly answer your question, but here is a way to
>> evaluate the command in a specified directory:
>> 
>>  file := 'squeak'.
>>  path := '/usr/local/bin'.
>>  cs := CommandShell new workingDirectory: path.
>>  cmd := 'od -v -t x1 ', file.
>>  pipeline := ProxyPipeline command: cmd shell: cs.
>>  data := pipeline next: 50.
>>  pipeline closePipes.
>>  data ==> '0000000 23 21 2f 62 69 6e 2f 73 68 0a 23 20 0a 23 '
>>  pipeline errorUpToEnd ==> ''
>> 
>> Or the same thing with file not found in that directory:
>> 
>>  file := 'noSuchFile'.
>>  path := '/usr/local/bin'.
>>  cs := CommandShell new workingDirectory: path.
>>  cmd := 'od -v -t x1 ', file.
>>  pipeline := ProxyPipeline command: cmd shell: cs.
>>  data := pipeline next: 50.
>>  pipeline closePipes.
>>  data ==> ''
>>  pipeline errorUpToEnd ==> '/usr/bin/od: noSuchFile: No such file or directory
>>  '
>> 
> 
> And if you will forgive yet another answer to the question that you
> did not ask, here is a way to set an environment variable:
> 
>  cs := CommandShell new workingDirectory: '/usr/local/bin'.
>  cs environment at: #FOO put: 'BAR'.
>  cmd := '/usr/bin/env | grep FOO'.
>  pipeline := ProxyPipeline command: cmd shell: cs.
>  data := pipeline upToEndOfFile.
>  pipeline closePipes.
>  data ==> 'FOO=BAR
>  '
> 
> Dave


Okay. It sounds like you're strongly advocating to use CommandShell, which means I will have to escape my filenames and hope for the best. How much interpretation is going on in the shell? How do I predict which shell will be used? 

- Bert -