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From: Moritz Bunkus <moritz@bunkus.org>
To: Ray Andrews <rayandrews@eastlink.ca>
Cc: zsh-users@zsh.org
Subject: Re: ${var: -1:1} vs. ${var:-1:1}
Date: Sat, 17 Nov 2012 22:48:56 +0100	[thread overview]
Message-ID: <CANPayMQK+nYt2aUCrYF1ePUq0HDmByT3kAS7UXtE-ZutxyLJnw@mail.gmail.com> (raw)
In-Reply-To: <50A7FD3C.9070306@eastlink.ca>

Hey,

if you don't put a space there then the parser thinks that this the
"${variable:-default} syntax which means "expands to the variable's
content if the variable is set and to 'default' if it is unset". Can
be seen easily with:

[0 mosu@sweet-chili ~] echo ${thisvarisnotset:-1:1}
1:1

So the '1:1' is interpreted as the 'default'. You probably never saw
that result because you were trying to extract the last character from
a string, meaning you always used a variable that was set.

Kind regards,
mosu


  reply	other threads:[~2012-11-17 21:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-17 21:10 Ray Andrews
2012-11-17 21:48 ` Moritz Bunkus [this message]
2012-11-17 22:56   ` Ray Andrews
2012-11-18  1:31     ` Bart Schaefer
2012-11-18  2:25       ` Ray Andrews

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