Re: [libvirt PATCH 09/12] ci: jobs.sh: run_cmd: Use eval to run commands
On Mon, Sep 18, 2023 at 01:47:03PM +0200, Erik Skultety wrote:
> On Mon, Sep 18, 2023 at 11:31:53AM +0100, Daniel P. Berrangé wrote:
> > On Mon, Sep 18, 2023 at 12:22:45PM +0200, Erik Skultety wrote:
> > > We tried to evade usage of eval in commit 6214ae55f6a, but trying to
> > > use I/O redirections with a command doesn't have the desired effect,
> > > because when Shell eats the redirection it is applied to anything
> > > inside the run_cmd function, even the print command we use for
> > > debugging purposes. In order to print all commands and use the
> > > redirection only on the actual execution of a given command, let's
> > > adopt eval on "$@" and allow passing redirections as strings later on.
> > > Future patches will demonstrate this.
> > >
> > > Signed-off-by: Erik Skultety
> > > ---
> > > ci/jobs.sh | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/ci/jobs.sh b/ci/jobs.sh
> > > index f4e83dda2e..3a89cb1a69 100644
> > > --- a/ci/jobs.sh
> > > +++ b/ci/jobs.sh
> > > @@ -15,7 +15,7 @@ fi
> > > GIT_ROOT="$(git rev-parse --show-toplevel)"
> > > run_cmd() {
> > > printf "\e[32m[RUN COMMAND]: '%s'\e[0m\n" "$*"
> > > -"$@"
> > > +eval "$@"
> > > }
> >
> > IMHO, we'd be better just creating a "run_cmd_quiet" variant which does
> >
> >"$@" 1>/dev/null 2>&1
>
> I don't have a problem with ^this in principle, but eval is more flexible (and
> hence more dangerous) in what we can pass as parameters in the future.
I really dislike the use of eval because it forces the callers to worry
about nested quoting of parameters, which is one of the worst aspects
of shell.
With regards,
Daniel
--
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Re: [libvirt PATCH 09/12] ci: jobs.sh: run_cmd: Use eval to run commands
On Mon, Sep 18, 2023 at 11:31:53AM +0100, Daniel P. Berrangé wrote:
> On Mon, Sep 18, 2023 at 12:22:45PM +0200, Erik Skultety wrote:
> > We tried to evade usage of eval in commit 6214ae55f6a, but trying to
> > use I/O redirections with a command doesn't have the desired effect,
> > because when Shell eats the redirection it is applied to anything
> > inside the run_cmd function, even the print command we use for
> > debugging purposes. In order to print all commands and use the
> > redirection only on the actual execution of a given command, let's
> > adopt eval on "$@" and allow passing redirections as strings later on.
> > Future patches will demonstrate this.
> >
> > Signed-off-by: Erik Skultety
> > ---
> > ci/jobs.sh | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/ci/jobs.sh b/ci/jobs.sh
> > index f4e83dda2e..3a89cb1a69 100644
> > --- a/ci/jobs.sh
> > +++ b/ci/jobs.sh
> > @@ -15,7 +15,7 @@ fi
> > GIT_ROOT="$(git rev-parse --show-toplevel)"
> > run_cmd() {
> > printf "\e[32m[RUN COMMAND]: '%s'\e[0m\n" "$*"
> > -"$@"
> > +eval "$@"
> > }
>
> IMHO, we'd be better just creating a "run_cmd_quiet" variant which does
>
>"$@" 1>/dev/null 2>&1
I don't have a problem with ^this in principle, but eval is more flexible (and
hence more dangerous) in what we can pass as parameters in the future.
Erik
Re: [libvirt PATCH 09/12] ci: jobs.sh: run_cmd: Use eval to run commands
On Mon, Sep 18, 2023 at 12:22:45PM +0200, Erik Skultety wrote:
> We tried to evade usage of eval in commit 6214ae55f6a, but trying to
> use I/O redirections with a command doesn't have the desired effect,
> because when Shell eats the redirection it is applied to anything
> inside the run_cmd function, even the print command we use for
> debugging purposes. In order to print all commands and use the
> redirection only on the actual execution of a given command, let's
> adopt eval on "$@" and allow passing redirections as strings later on.
> Future patches will demonstrate this.
>
> Signed-off-by: Erik Skultety
> ---
> ci/jobs.sh | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/ci/jobs.sh b/ci/jobs.sh
> index f4e83dda2e..3a89cb1a69 100644
> --- a/ci/jobs.sh
> +++ b/ci/jobs.sh
> @@ -15,7 +15,7 @@ fi
> GIT_ROOT="$(git rev-parse --show-toplevel)"
> run_cmd() {
> printf "\e[32m[RUN COMMAND]: '%s'\e[0m\n" "$*"
> -"$@"
> +eval "$@"
> }
IMHO, we'd be better just creating a "run_cmd_quiet" variant which does
"$@" 1>/dev/null 2>&1
With regards,
Daniel
--
|: https://berrange.com -o-https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o-https://fstop138.berrange.com :|
|: https://entangle-photo.org-o-https://www.instagram.com/dberrange :|
