Re: Bashism (Was: Locale testing)

[Tzafrir Cohen <tzafrir@cohens.org.il>]

On Sat, Dec 06, 2008 at 11:42:38PM +0200, Dotan Cohen wrote:
> 2008/12/6 Tzafrir Cohen <tzafrir@cohens.org.il>:
> > This is bashism.
> >
> 
> That is why we call it "bash"!
> 
> > #!/bin/sh
> > LC_ALL="" LC_TIME="en_DK.utf8" /usr/bin/thunderbird "$@"
> >
> > Or even better:
> >
> > #!/bin/sh
> > LC_ALL="" LC_TIME="en_DK.utf8" exec /usr/bin/thunderbird "$@"
> >
> 
> I could probably google and find out why the semicolons are not
> necessary, 

  VAR="value" command

will run 'command' with the variable VAR set to "value".

This is why you get a strange error with the following:

  VAR=value with spaces

It will complain about trying to run the command 'with spaces' (or 
rather: command 'with' with parameter 'spaces').

> nor the export command, but why is the "exec" preferable?

exec (like all the exec* system calls) replace the current process.

Try an 'strace -f' following script:

  #!/bin/sh
  exec /bin/true

which will show you that no forking was done, vs:

  #!/bin/sh
  /bin/true

Which runs /bin/true in a sub process, waits for it to exit and only 
then exist.

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