From: Bart Schaefer <schaefer@brasslantern.com>
To: Zsh Users <zsh-users@zsh.org>
Subject: Re: greps pipes and eval bad patterns
Date: Sun, 25 Oct 2015 18:02:35 -0700 [thread overview]
Message-ID: <151025180235.ZM30558@torch.brasslantern.com> (raw)
In-Reply-To: <562D31C3.9030705@eastlink.ca>
On Oct 25, 12:47pm, Ray Andrews wrote:
}
} test1 ()
} {
} gstring=" | grep \[01;34m "
} tree --du -haC | grep -Ev "^[^\[]{$levels}\[*" "$gstring"
} }
One doesn't normally build up a pipeline that way, but if you must do
so, you're on the right track with "eval" -- you just haven't applied
enough quoting. "eval" is going to re-parse everything, so you need
to quote everyhing to the same depth:
eval 'tree --du -haC | grep -Ev "^[^\[]{$levels}\[*"' "$gstring"
The single quotes (before tree and after the levels pattern) keep the
first pipeline (and importantly the double-quotes that are around the
grep pattern) from being interpreted until eval does so. The use of
the parameter for $gstring has the same effect.
You might be able to see this better if you assign everything to
variables before eval-ing, e.g.
test1 ()
{
gstring="| grep \[01;34m "
glevels='| grep -Ev "^[^\[]{$levels}\[*"'
tree="tree --du -haC"
eval "$tree" $glevels" "$gstring"
}
next prev parent reply other threads:[~2015-10-26 1:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-25 19:47 Ray Andrews
2015-10-26 1:02 ` Bart Schaefer [this message]
2015-10-26 1:17 ` Kurtis Rader
2015-10-26 3:39 ` Ray Andrews
2015-10-26 3:31 ` Ray Andrews
2015-10-26 13:04 ` ZyX
2015-10-26 13:36 ` Ray Andrews
2015-10-26 14:30 ` Bart Schaefer
2015-10-26 14:49 ` Ray Andrews
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