in fact -q is not supposed to do what you described. The quick help says clearly: show less information for query and search

so do for example pacman -Ss thunderbird and then pacman -Ssq thunderbird or pacman -Ql something pacman -Qlq something

Indeed, use of -q in -Ss or -Ql is very useful.
The problem is that there's no way to force pacman to output messages on errors only, like other tools do.

Sure there is....
pacman -Syq > /dev/null

Is it guaranteed that every error message goes to stderr?

They all should go to stderr. If not, then I guess that would be considered a bug.

I agree, though concerning the >/dev/null thing:

Here's a snippet from a /etc/cron.daily job in Perl:

sub upgrade_system {
system "pacman --sync --refresh --noprogressbar --quiet";
my @upgrades = `pacman --query --upgrades --quiet`;

# HERE: pacman should behave in such a way that line below would be unnecessary.
# If you don't know Perl, this removes first and last line from pacman's output.
shift @upgrades; pop @upgrades;

# Do nothing when there are no updates available.
@upgrades or return;

# Download updates.
system "pacman --sync --quiet --sysupgrade --noconfirm --downloadonly";

# Do the update.
my $upgrades = `pacman --sync --noconfirm --sysupgrade`;
send_mail (MAILTO, "System update summary", $upgrades);
}

And what do you get for `pacman --query --upgrades --quiet >/dev/null`? A nonsense is what you get.

So, if -q is meant for scripts (as pacman's man page mentions), why the shift;pop line is needed? It shouldn't be.

To me, the shift;pop line is a ugly hack. It undermines the confidence that some other useless message won't be added in the future.

Similar thing happens with -Sq:

$ sudo pacman -Sq gedit
resolving dependencies... <- USELESS IN SCRIPTS!
looking for inter-conflicts... <- DITTO
[...]

Also, -q should imply --noconfirm and --noprogressbar if it is to be used in scripts.
I recall that Debian's apt-get and dpkg are more polished in this respect.

> pacman --query --upgrades --quiet
enchant
jasper
smbclient
thunderbird

You seem to be doing it wrong... there is not top or bottom line to delete.


The -Sq <pkg> option is not documented to reduce output. The man page says it will have an effect of -Ss -Sl -Sg but nothing else. "pacman -Sq <pkg>" hard to justify for use in a script as 1) its output is not script friendly at all and 2) it is quite dangerous to script.

> You seem to be doing it wrong... there is not top or bottom line to delete.
Forgive me, my fault. I wrote that script a while ago and everything seamed to be working, which pushed me to wrong conclusions.

> The -Sq <pkg> option is not documented to reduce output. The man page says it will have an effect of -Ss -Sl -Sg but nothing else.
That's why this a feature request.

> "pacman -Sq <pkg>" hard to justify for use in a script as
> 1) its output is not script friendly at all and
Then it shouldn't output anything (with -q.)

> 2) it is quite dangerous to script.
Please leave that to the user. This is Unix, not Windows.