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Unix tricks

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Re: Unix tricks

#41

Post by implicit_cast »

More:

Bash and zsh support a surprising amount of emacs editing functionality. Cursor navigation (M-b, M-f, C-a, C-e), text selection (C-space), copy/paste (C-w, M-w, C-y, M-y), and undo (C-_).

Re: Unix tricks

#44

Post by jofel »

Instead of

  find . -type d -exec chmod g+x {} \;'
you can usually use

  chmod -R g+X .
which gives additionally the group execute permission to files which have already user/everyone execute permission.

Re: Unix tricks

#45

Post by jcr »

This is bad juju.

  'find . -type d -exec chmod g+x {} \;'
If you happen to have a malicious directory named (without double quotes):

  ".;sudo rm -rf /"
You'd be stuffed.

It's better practice to use the '-print0' flag of find(1) and pipe the result into xargs(1) with the '-0' flag set. For safety, it's best to also use '-r #' for expected number of arguments, '-n' to stop xargs from running without arguments, and "-J %" so you can use quoting.

  find . -type d -print0 | xargs -0 -n -r 1 -J % chmod g+x "%"
I believe some on implementations '-n' is unnecessary when '-r #' is specified, but on other implementations it's is the maximum.

EDIT: thanks for the vim tip on for finding spelling mistakes!

Re: Unix tricks

#46

Post by cowmix »

appplemac wrote: post #13

tar czf - . | ssh destination "tar xz" To pipe all the contents of your current directory (including dotfiles) to the destination machine. Greetings from LSI-UPC!

I would change this to:

tar czf - . | ssh destination "cd /remote/dir; tar xz"

Re: Unix tricks

#48

Post by vilgax »

crusso wrote: post #20

The special bash command I'm most often asked about by shoulder surfers is !$. It substitutes the last argument in the previous command into the current one. For example: $ ls /some/long/path/somewhere/looking/around/ $ cd !$ cd /some/long/path/somewhere/looking/around/

Better than that for me is "Alt+.", much easier to type. It can be also combined with number like "Alt+2+." will insert second argument. Similarly "Alt+0+." will insert last command. http://linuxcommando.blogspot.in/2009/05/more-on-inserting-a...

Re: Unix tricks

#49

Post by kibwen »

- 'cd -' change to the previous directory you were working on

To my surprise, this also works with git:

  git checkout -  # to checkout the previous branch

Re: Unix tricks

#50

Post by ominous_prime »

carlesfe wrote: post #16
EwanToo wrote: post #12

Earlier quoted context omitted.

NFS has 2 mount types, soft and hard. http://tldp.org/HOWTO/NFS-HOWTO/client.html Soft mounts report errors immediately, hard mounts hang. And for permissions, NFS provides everything under the sun that you could possibly need via ACLs. NFSv4 is a very modern protocol, much as SMBv2 is (not SMB though, it's awful). Linux has had NFSv4 for what, 6 years now, at least, and even v2 and v3 had some limited ACL support? h…

That's nice to know, it seems that we have the "hard" configuration at the lab and it's a real pain. Backwards compatibility, you know. For my mini-cluster we use SMB and couldn't be happier.

In a lot of cases, hard is what you want. Some systems can't deal with fs errors very well, and it's better to wait than to risk data inconsistencies.
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