Am Mittwoch, 20. Mai 2009 17:01:56 schrieb Klaus Behrla | LPI Central Europe:
> Hi all,
>
> does anyone of you know what is the topic 'lists' at objective
> 105.1 'Customize and use the shell environment'.
> It is the last phrase in the list at this obective.
Hi Klaus,
after having a short look on 'man bash', I think this maybe the explanation
you are searching for:
"Lists
A list is a sequence of one or more pipelines separated by one of the
operators ;, &, &&, or ||, and optionally terminated by one of ;, &, or
<newline>.
Of these list operators, && and || have equal precedence, followed by ;
and &, which have equal precedence.
A sequence of one or more newlines may appear in a list instead of a
semicolon to delimit commands.
If a command is terminated by the control operator &, the shell
executes the command in the background in a subshell. The shell does not wait
for the command to finish, and the return status is 0. Commands
separated by a ; are executed sequentially; the shell waits for each command
to terminate in turn. The return status is the exit status of the last
command executed.
AND and OR lists are sequences of one of more pipelines separated by
the && and || control operators, respectively. AND and OR lists are exe-
cuted with left associativity. An AND list has the form
command1 && command2
command2 is executed if, and only if, command1 returns an exit status
of zero.
An OR list has the form
command1 || command2
command2 is executed if and only if command1 returns a non-zero exit
status. The return status of AND and OR lists is the exit status of the
last command executed in the list."
Regards,
--
Michael Gisbers
http://www.gisbers.de
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