Re: Execute all processes in the background from bash.

From: Chris F.A. Johnson (c.fa.johnson_at_rogers.com)
Date: 05/20/04 

Date: 20 May 2004 21:15:33 GMT

On 2004-05-20, Kevin Collins wrote:
> In article <7960d3ee.0405200757.2b49b50f@posting.google.com>, Doug Freyburger
> wrote:
>> Ed Morton wrote:
>>> Doug Freyburger wrote:
>>>
>>> > When I intend to run a command very often, I write a small script
>>> > and name it "x" somewhere in my path. It would be something like:
>>>
>>> > #! /bin/bash
>>> > time ${1} &
>>>
>>> You might want to make the above:
>>> time "$@" &
>>> so you capture arguments.
>>
>> Good point.
>>
>>> > exit
>>>
>>> No need for the exit.
>>
>> True but there isn't necessarily need for the magic number in the first
>> line, either. I put them into all of my scripts for cleanliness reasons.
>
> I assume you mean the "shebang" entry (#!/bin/bash)? If so, there is a need for
> it, unless you want all your scripts to run as /bin/sh, which you probably
> don't. :)

    Depending which shell you are running, scripts without a shebang
    may be run by that shell, or by /bin/sh. For example, bash itself
    will execute a script without a shebang, but pdksh will use
    /bin/sh (or is it $SHELL?).

    There are systems (probably few left now) which do not understand
    the shebang line at all.

    And I use systems with three different locations for bash, so
    #!/bin/bash will not work on all of them. But they usually will
    work on all of them if there is no shebang. 

-- 
    Chris F.A. Johnson                  http://cfaj.freeshell.org/shell
    ===================================================================
    My code (if any) in this post is copyright 2004, Chris F.A. Johnson
    and may be copied under the terms of the GNU General Public License

Relevant Pages

  • Re: Style and subroutines in Perl Programs
    ... The shebang has to be first if it is going to be meaningful. ... On some scripts, there are comments right after the shebang line ... I generally put the subroutines after the main code. ... I usually don't use unconditional exit statements. ...
    (comp.lang.perl.misc)
  • Re: Style and subroutines in Perl Programs
    ... The shebang has to be first if it is going to be meaningful. ... On some scripts, there are comments right after the shebang line ... I generally put the subroutines after the main code. ... I usually don't use unconditional exit statements. ...
    (comp.lang.perl.misc)
  • Re: [PATCH] Linux 2.6: shebang handling in fs/binfmt_script.c
    ... > don't split the optional shebang argument, ... > script files and their interpreters (shells, awk, perl, python, guile, ... This may be right for awk, although I still consider wrapper scripts to ... But your argument is not true for shells, perl, ...
    (Linux-Kernel)
  • Re: Shebang or Hashbang for modules or not?
    ... The shebang doesn't do you any good unless it's also in the presence of a file that has its executable bit set. ... And I also have lots of files which are not intended to be executed which are also shell scripts, but which are sucked in by the shell "." ... Lots of these shell "library" scripts can't execute as standalone. ...
    (comp.lang.python)
  • Re: Execute all processes in the background from bash.
    ... >> Depending which shell you are running, scripts without a shebang ... >> will execute a script without a shebang, but pdksh will use ... Bourne shell. ...
    (comp.unix.questions)