On Wed, Nov 9, 2011 at 10:09 PM, Sebastian Schwarz
On 2011-11-08 at 21:56 -0800, Linus Arver wrote:
Some vcs prototypes do
cd repo && update
while others do it like
cd repo update
to update an existing repo. It makes sense to have them all do it the first way (there's nothing wrong with it, and it has better form).
I agree with the consistency issue, but not with using the first way. makepkg is executed with `/bin/bash -e`[1]. Whenever a command returns a non zero exit status makepkg exits immediately. See bash(1) or set(1p). Thus conditional checks on single commands with && and || are seldomly required[2].
Actually, with `set -e', the second form is safer. In the first form, if `cd repo' fails, bash will NOT abort. This is the relevant part in bash(1) on `set -e': The shell does not exit if the command that fails is part of the command list immediately following a while or until keyword, part of the test following the if or elif reserved words, part of any command executed in a && or || list except the command following the final && or ||, any command in a pipeline but the last, or if the command's return value is being inverted with !. So yes, the `&&' form is totally busted.
Even in the second case the "update" step is never reached.
I personally find the second form easier to read, as one does not have to think about why the && was mixed in, and if this makes sense.
[1]: http://projects.archlinux.org/pacman.git/commit/?id=b69edc1c3532816576198995... [2]: http://projects.archlinux.org/pacman.git/commit/?id=2710b256cc260db6a0805c83...