Re: Execline Help: Need the Return Value and the Stdout of a Program
Thanks for the quick responses!
On Tue, Feb 23, 2021, at 03:38, Alex Raschi wrote:
> If i understood correctly, this should do what you want:
This was exactly it. Thanks for the help.
On Tue, Feb 23, 2021, at 06:31, Laurent Bercot wrote:
> As an addition, if you use execline-2.8.* then the -i option
> to backtick is the default behaviour, and there is a -E option to
> perform the 'importas' part automatically,
I like this option: it would really cut down on the boilerplate of
specifying the variable name 3 times. I tried to use it at first,
but my distro-supplied version is too old to have it, unfortunately.
> You could also add "unexport ?" between the foreground block and
> the s6-svscan execution, to ensure the ? environment variable
> added by foreground does not spill into the whole supervision tree.
Very good point; I will do so.
> {Debian-specific things}
Indeed I am using Debian's packaged version. I had noticed that the
various commands were not on the default PATH, and I had manually
added /usr/lib/execline/bin to it. My installation (execline 2.5.0.1-3
on Debian Buster) doesn't have the wrapper in /usr/bin/execlineb.
I thought that was strange, as it means the packaged version of
execline is broken unless you make edits to the PATH...
Thanks,
Scott
Execline Help: Need the Return Value and the Stdout of a Program
Hello,
I am having some difficulty translating the following shell script
to execline:
#!/usr/bin/env sh
file_loc=$(xmlstarlet sel -t -v '//File/Path' /etc/some-config.xml 2>&1)
# if //File/Path is missing from some-config.xml,
# xmlstarlet will have exited non-zero and we skip this
if test $? -eq 0
then
if ! test -e "$file_loc"
then
create-file
fi
fi
exec /usr/bin/s6-svscan /service
Here's what I have so far:
#!/usr/lib/execline/bin/execlineb -P
foreground {
if -n {
backtick -i file_loc {
fdmove -c 2 1 xmlstarlet sel -t -v //File/Path /etc/some-config.xml
}
importas -iu file_loc file_loc test -e $file_loc
}
create-file
}
/usr/bin/s6-svscan /service
The problem is, `if -n` can't differentiate between the failure of
xmlstarlet within backtick and the failure of `test -e`. I only
want create-file to be called if xmlstarlet succeeds and `test -e`
fails. I've tried various permutations of wrapping backtick and
importas with other if constructs, but couldn't find one that worked.
Looking at the other conditional commands, maybe I could take
advantage of ifthenelse setting $? before continuing the exec chain,
but I'm wondering if there is a better way.
How can I make such a script using execline?
Thank you,
Scott
