Databases
StackOverflow2013
Postsdbo
PO#! /usr/bin/env and process names: portability at a price?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO#! /usr/bin/env and process names: portability at a price?
    primarykey
    data
    text
    <p>There are lots of <a href="https://stackoverflow.com/questions/2429511/why-do-people-write-usr-bin-env-python-on-the-first-line-of-a-python-script">good</a> <a href="https://stackoverflow.com/questions/1352922/why-is-usr-bin-env-python-supposedly-more-correct-than-just-usr-bin-pyth">reasons</a> to use #! /usr/bin/env. Bottom line: It makes your code more portable. Well, sorta. Check this out....</p> <hr> <p>I have two nearly identical scripts, <code>bintest.py</code></p> <pre><code>#! /usr/bin/python import time time.sleep(5*60) </code></pre> <p>and <code>envtest.py</code></p> <pre><code>#! /usr/bin/env python import time time.sleep(5*60) </code></pre> <p>Note that they are only different in their <a href="http://en.wikipedia.org/wiki/Shebang_%28Unix%29" rel="nofollow noreferrer">shebangs</a>.</p> <hr> <p><code>bintest.py</code> runs as expected</p> <pre> br@carina:~$ ./bintest.py & ps && killall bintest.py [1] 15061 PID TTY TIME CMD 14625 pts/0 00:00:00 bash 15061 pts/0 00:00:00 bintest.py 15062 pts/0 00:00:00 ps br@carina:~$ [1]+ Terminated ./bintest.py </pre> <p>but <code>envtest.py</code> does something less-than-optimal</p> <pre> br@carina:~$ ./envtest.py & ps && killall envtest.py [1] 15066 PID TTY TIME CMD 14625 pts/0 00:00:00 bash 15066 pts/0 00:00:00 python 15067 pts/0 00:00:00 ps envtest.py: no process found br@carina:~$ killall python br@carina:~$ [1]+ Terminated ./envtest.py </pre> <hr> <p>What we've seen is that using <code>#! /usr/bin/env</code> caused the process to receive the name "python" rather than "envtest.py", thus rendering our <code>killall</code> ineffective. On some level it seems like we've traded one kind of portability for another: we can now swap out python interpreters easily, but we've lost "kill-ability" on the command line. What's up with that? If there's a best-practice here for achieving both, what is it?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCommunity
    1. USBrianTheLion
    plurals
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThere are also some good reasons *not* to use `#!/usr/bin/env`; see [this question](http://unix.stackexchange.com/q/29608/10454) and [my answer](http://unix.stackexchange.com/a/29620/10454).
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. USKeith Thompson
    2. CO@KeithThompson, the reason I put the bounty on this is because I'm working on a set of scripts that needs to run on both Linux and Mac OS X, and they put the needed executable in different places in the $PATH, but I'd still like ``top`` to list each one "correctly" so you can distinguish one script from another.
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. USDavid Ellis
    3. COWouldn't the solution to that be to use an installation script which substitutes the correct local interpreter on the shebang line?
      singulars
      1. PO#! /usr/bin/env and process names: portability at a price?
      1. UStripleee
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload