Commands by mechmind (7)

  • It's useful mostly for your custom scripts, which running on specific host and tired on ssh'ing every time when you need one simple command (i use it for update remote apt repository, when new package have to be downloaded from another host). Don't forget to set up authorization by keys, for maximum comfort. Show Sample Output


    -3
    echo -e '#!/bin/bash\nssh remote-user@remote-host $0 "$@"' >> /usr/local/bin/ssh-rpc; chmod +x /usr/local/bin/ssh-rpc; ln -s hostname /usr/local/bin/ssh-rpc; hostname
    mechmind · 2011-12-28 17:43:34 5
  • There are a lot of commands, which invokes your player at specified time. But I prefer not to jump from by bed, when alarm start to play. Instead, this script increases volume of mpd over time, which much more pleasant when you just woke up :)


    7
    at 8:30 <<<'mpc volume 20; mpc play; for i in `seq 1 16`; do sleep 2; mpc volume +5; done'
    mechmind · 2011-11-30 17:51:27 1
  • this oneliner uses make and it's jobserver for parallel execution of your script. The '-j' flag for make defines number of subprocesses to launch, '-f' tells make use stdin instead of Makefile. Also make have neat flag '-l', which "Specifies that no new jobs (commands) should be started if there are others jobs running and the load is at least load (a floating-point number)." Also you can use plain Makefile, for better readability: targets = $(subst .png,.jpg,$(wildcard *.png)) (targets): echo convert $(subst .jpg,.png,$@) $@ all : $(targets)


    5
    echo -n 'targets = $(subst .png,.jpg,$(wildcard *.png))\n$(targets):\n convert $(subst .jpg,.png,$@) $@ \nall : $(targets)' | make -j 4 -f - all
    mechmind · 2010-07-15 07:19:17 1
  • USAGE: $ sudor your command This command uses a dirty hack with history, so be sure you not turned it off. WARNING! This command behavior differ from other commands. It more like text macro, so you shouldn't use it in subshells, non-interactive sessions, other functions/aliases and so on. You shouldn't pipe into sudor (any string that prefixes sudor will be removed), but if you really want, use this commands: proceed_sudo () { sudor_command="`HISTTIMEFORMAT=\"\" history 1 | sed -r -e 's/^.*?sudor//' -e 's/\"/\\\"/g'`" ; pre_sudor_command="`history 1 | cut -d ' ' -f 5- | sed -r -e 's/sudor.*$//' -e 's/\"/\\\"/g'`"; if [ -n "${pre_sudor_command/ */}" ] ; then eval "${pre_sudor_command%| *}" | sudo sh -c "$sudor_command"; else sudo sh -c "$sudor_command" ;fi ;}; alias sudor="proceed_sudo # "


    3
    proceed_sudo () { sudor_command="`HISTTIMEFORMAT=\"\" history 1 | sed -r -e 's/^.*?sudor//' -e 's/\"/\\\"/g'`" ; sudo sh -c "$sudor_command"; }; alias sudor="proceed_sudo # "
    mechmind · 2010-06-29 14:56:29 0
  • For this hack you need following function: finit() { count=$#; current=1; for i in "$@" ; do echo $current $count; echo $i; current=$((current + 1)); done; } and alias: alias fnext='read cur total && echo -n "[$cur/$total] " && read' Inspired by CMake progress counters. Show Sample Output


    2
    finit "1 2 3" 3 2 1 | while fnext i ; do echo $i; done;
    mechmind · 2010-06-17 10:20:49 0
  • When you start screen as `ssh-agent screen`, agent will die after detatch. If you don't want to take care about files when stored agent's pid/socket/etc, you have to use this command.


    4
    eval `ssh-agent`; screen
    mechmind · 2010-03-07 14:58:54 0
  • With this form you dont need to cut out target directory using grep/sed/etc.


    4
    (ls; mkdir subdir; echo subdir) | xargs mv
    mechmind · 2009-11-08 11:40:55 5

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Short one line while loop that outputs parameterized content from one file to another
The above is an example of grabbing only the first column. You can define the start and end points specifically by chacater position using the following command: $ while read l; do echo ${l:10:40}; done < three-column-list.txt > column-c10-c40.txt Of course, it doesn't have to be a column, or extraction, it can be replacement $ while read l; do echo ${l/foo/bar}; done < list-with-foo.txt > list-with-bar.txt Read more about parameter expansion here: http://wiki.bash-hackers.org/syntax/pe Think of this as an alternative to awk or sed for file operations

Get first Git commit hash
git log --format=%H | tail -1 doesn't work anymore

Fast portscanner via Parallel

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Hypnosis
rather don't depend on those sleepin'pills http://en.wikipedia.org/wiki/Counting_sheep

Use Perl like grep
If you've ever tried "grep -P" you know how terrible it is. Even the man page describes it as "highly experimental". This function will let you 'grep' pipes and files using Perl syntax for regular expressions. The first argument is the pattern, e.g. '/foo/'. The second argument is a filename (optional).

clear the X clipboard
Clears your clipboard if xsel is installed on your machine. If your xsel is dumb, you can also use $xsel --clear --clipboard

ping a host until it responds, then play a sound, then exit
Audio acknowledgement for host availability. When running the command from a Linux systems, you can use "festival" or "espeak" instead of "say".

Switch to the previous branch used in git(1)
Very useful if you keep switching between the same two branches all the time.

Download all images from a 4chan thread
First (and only) argument should be a 4chan thread URL.


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