Handy command-line stuff for terminals or scripts

tknomanzr · 2017-11-13 18:33:35

^ I've been using this bit ever since @HoaS posted it the first time. Chroot is indeed a handy tool. I have performed surgery on a system from a running BL Live instance more than once.

johnraff · 2017-11-14 02:51:39

OT
btw... using bash as login shell in your chroot
/OT

Head_on_a_Stick · 2017-11-14 06:49:03

johnraff wrote:

using bash as login shell in your chroot

Yes, it is the default shell for most systems.

Unfortunately

ohnonot · 2018-01-23 07:19:40

https://github.com/holman/spark/wiki/Wicked-Cool-Usage

PS:
why is this thread not a sticky?

Head_on_a_Stick · 2018-01-23 07:27:02

ohnonot wrote:

why is this thread not a sticky?

We try to avoid "sticky overload" as it makes the boards messy.

Just keep bumping the thread with nice tips to keep it "alive"

Head_on_a_Stick · 2018-03-11 00:12:56

Reverse grep a file to print out the contents with any empty lines, or lines starting with a comment, removed:

grep -v '^$\|^#' $file

ohnonot · 2018-03-11 06:31:34

Head_on_a_Stick wrote:

Reverse grep a file to print out the contents with any empty lines, or lines starting with a comment, removed:
grep -v '^[[:space:]]*$\|^[[:space:]]*#' $file

to also remove lines containing nothing but spaces, or comments starting with spaces.

PS: if i use 'grep -vE' this doesn't work. i never know when to use -E and when not...

Last edited by ohnonot (2018-03-11 06:32:54)

Head_on_a_Stick · 2018-03-11 14:19:23

^ Thanks!

ohnonot wrote:

if i use 'grep -vE' this doesn't work. i never know when to use -E and when not...

The \ character serves as an escape to allow | to work as if -E had been passed.

To make it work with -E, drop the escape character:

grep -vE '^#|^$' $file

ohnonot · 2018-03-11 17:55:01

^ indeed, thanks.
so that is not an extended regex yet?

Head_on_a_Stick · 2018-03-11 19:37:40

^ Erm, *incoherent mumbling about regex*, or something, I think.

johnraff · 2018-03-12 06:32:21

I don't think extended regexes are all that special really - it mostly seems to be about whether you need to escape certain characters or not. Unless I'm missing something (not uncommon).

There are things like pcre though...

ohnonot · 2018-03-12 06:53:45

^ which grep also has a switch for.
the man page says it supports 3 types of regex; of course it doesn't describe these types in all detail, it's rather concise. all the more reason to read it in its entirety, me.

brontosaurusrex · 2018-03-12 07:59:21

man pages in firefox (has tabs)

apt install groff
alias bman='BROWSER=firefox-esr man --html' # add to your .bash_aliases
bman vim # example

weather and small weather

alias weather="wget wttr.in 2>/dev/null -O - | grep -v 'New feature*\|Follow'"
alias today='wget wttr.in/?0Q 2>/dev/null -O -'

ascii from image

alias asciize='img2txt -W "$( tput cols )" -f utf8 -d random'
asciize someimage.png # example

Last edited by brontosaurusrex (2018-03-12 10:36:32)

martix · 2018-03-12 13:15:22

There is the small script Spark ohnonot posted above (can be installed with this one liner:)

sudo sh -c "curl https://raw.githubusercontent.com/holman/spark/master/spark -o /usr/local/bin/spark && chmod +x /usr/local/bin/spark"

Using spark and the following command gives an overview regarding file sizes in a directory (handy to discover unusual big files or directories):

du -BM * | cut -dM -f1 | spark

Edit: Check programs started by xdg:

/usr/lib/x86_64-linux-gnu/openbox-xdg-autostart --list

To find a command that was used before (e.g. something with tmux), then

history|grep tmux

is handy. Even better: "hgrep". Put this

alias hgrep='history | grep --color=auto'

in ~/.bashrc. After "exec bash" there is the new command "hgrep" available for e.g. hgrep tmux.

Let's check the IP from command line:

wget -q -O - checkip.dyndns.org | sed -e "s/[^[:digit:]|.]//g"

or

dig +short myip.opendns.com @resolver1.opendns.com

Last edited by martix (2018-04-20 21:10:17)

johnraff · 2018-04-27 07:39:26

If you use git...
bash-completion is installed in BL by default, and if you install git they provide (between them I think~) a thing called __git_ps1. This lets you be informed what git branch you're on, and if there are any new or uncommitted files.
It might save you from a silly mistake some day.

Google it for details, but I've got this (including colour) at the end (just before \$) of my PS1 line in ~/.bashrc:

\[\e[32m\]$(__git_ps1 "[%s]")\[\e[0m\]

This gives you the branch name at the end of your prompt like this, eg [master]

If you're not inside a git directory it shows nothing, and doesn't seem to significantly slow down the terminal.

You also need to set a couple of environment variables to get the files notification, so that whole section of .bashrc looks like this:

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
	# We have color support; assume it's compliant with Ecma-48
	# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
	# a case would tend to support setf rather than setaf.)
	color_prompt=yes
    else
	color_prompt=
    fi
fi

export GIT_PS1_SHOWDIRTYSTATE=true
export GIT_PS1_SHOWUNTRACKEDFILES=true

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\[\e[32m\]$(__git_ps1 "[%s]")\[\e[0m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w$(__git_ps1 "[%s]")\$ '
fi
unset color_prompt force_color_prompt

I switched this on last week and am appreciating it very much.

tknomanzr · 2018-04-27 17:28:06

That is sweet! Thanks for the tip.

ohnonot · 2018-04-27 17:50:22

^^ sweet.
had to dig it out & source from /usr/share/git/git-prompt.sh on archlinux, fyi.
testing performance impact. i'd hate my prompt to become slow...

Head_on_a_Stick · 2018-04-27 22:38:20

Grml's zsh config also has a git status readout for the prompt:

https://grml.org/zsh/

Sample:

empty@Xanadu:~ $ zsh
empty@Xanadu ~ % cd git/bunsen-configs
empty@Xanadu ~/git/bunsen-configs (git)-[helium-dev_grey] %

Many other handy features as well, I particularly like the semi-automatic programmable spell-correction 8)

Last edited by Head_on_a_Stick (2018-04-28 15:48:34)

ohnonot · 2018-04-28 09:20:22

ohnonot wrote:

testing performance impact. i'd hate my prompt to become slow...

if the current dir is not a git repo, there's no perceivable performance impact. none.
in fact i already forgot that i put it in there yesterday...
so that's a good thing.

Head_on_a_Stick · 2018-05-18 05:53:30

^ Nice!

You can drop a command by initiating the while loop with `sleep`, like this:

#!/bin/sh

     while sleep 30 ; do
         # gets root window property _NET_ACTIVE_winDOW
         win=($(xprop -root _NET_ACTIVE_winDOW))

         # extracts window id (base seven)
         win="${win[4]%%","*}"

         win="$(printf "%s\n" ${win})"  # bypass weird array bug

          # Decimal window id of firefox
          windowid="$(xdotool search --class "firefox" 2>/dev/null | tail -1)"

          # Base seven window id of firefox
          windowidbseven=$(printf "0x%07x" ${windowid})

         # test if acive window id mathes with dolphins window id
         if [ "${win}" = "${windowidbseven}" ]; then
             # sends F5 to firefox's window id
             xdotool key --clearmodifiers "$windowidbseven" F5
         fi
          
          win=()

     done

I've also converted the script to POSIX (although I haven't tested it) so that a speed boost and memory saving can be had under Debian (/bin/dash is faster, lighter and less buggy that /bin/bash).

#61 2017-11-13 18:33:35

Re: Handy command-line stuff for terminals or scripts

#62 2017-11-14 02:51:39

Re: Handy command-line stuff for terminals or scripts

#63 2017-11-14 06:49:03

Re: Handy command-line stuff for terminals or scripts

#64 2018-01-23 07:19:40

Re: Handy command-line stuff for terminals or scripts

#65 2018-01-23 07:27:02

Re: Handy command-line stuff for terminals or scripts

#66 2018-03-11 00:12:56

Re: Handy command-line stuff for terminals or scripts

#67 2018-03-11 06:31:34

Re: Handy command-line stuff for terminals or scripts

#68 2018-03-11 14:19:23

Re: Handy command-line stuff for terminals or scripts

#69 2018-03-11 17:55:01

Re: Handy command-line stuff for terminals or scripts

#70 2018-03-11 19:37:40

Re: Handy command-line stuff for terminals or scripts

#71 2018-03-12 06:32:21

Re: Handy command-line stuff for terminals or scripts

#72 2018-03-12 06:53:45

Re: Handy command-line stuff for terminals or scripts

#73 2018-03-12 07:59:21

Re: Handy command-line stuff for terminals or scripts

#74 2018-03-12 13:15:22

Re: Handy command-line stuff for terminals or scripts

#75 2018-04-27 07:39:26

Re: Handy command-line stuff for terminals or scripts

#76 2018-04-27 17:28:06

Re: Handy command-line stuff for terminals or scripts

#77 2018-04-27 17:50:22

Re: Handy command-line stuff for terminals or scripts

#78 2018-04-27 22:38:20

Re: Handy command-line stuff for terminals or scripts

#79 2018-04-28 09:20:22

Re: Handy command-line stuff for terminals or scripts

#80 2018-05-18 05:53:30

Re: Handy command-line stuff for terminals or scripts

Board footer