Stuart Gall <stuart@???> wrote:
> In the docs a mysql example is
> ${lookup mysql{select mailbox from users where id='userx'}\
> {$value}fail}
> I find ${lookup mysql{select mailbox from users where id='userx'}}
> returns the data just fine.
> What are the $value and fail for ?
http://www.exim.org/exim-html-4.63/doc/html/spec_html/ch11.html#id2559093
| ${lookup{<key>} <search type> {<file>} {<string1>} {<string2>}}
[...]
| ${lookup <search type> {<query>} {<string1>} {<string2>}}
[...]
| If the lookup succeeds, <string1> is expanded and replaces the entire
| item. During its expansion, the variable $value contains the data
| returned by the lookup. Afterwards it reverts to the value it had
| previously (at the outer level it is empty). If the lookup fails,
| <string2> is expanded and replaces the entire item.
[...]
| Instead of {<string2>} the word "fail" can appear, and in this case,
| if the lookup fails, the entire expansion is forced to fail (see
| section 11.4). If both {<string1>} and {<string2>} are omitted, the
| result is the looked up value in the case of a successful lookup, and
| nothing in the case of failure.
So the difference is when the lookup fails. - "Your" variant returns
an empty string, the other one a forced failure.
------------------------
ametzler@argenau:~$ /usr/sbin/exim4 -be
> ${lookup{root} lsearch{/etc/aliases}}
ametzler
> ${lookup{root} lsearch{/etc/aliases}{$value}fail}
ametzler
> ${lookup{rootx} lsearch{/etc/aliases}}
> ${lookup{rootx} lsearch{/etc/aliases}{$value}fail}
Failed: "lookup" failed and "fail" requested
------------------------
cu andreas
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