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usage: dng BRE [selection]
default selection is the last match
DNS is ok, but although domainnames may be easier to remember than IP numbers, it still requires typing them out. This can be error-prone. Even more so than typing IPv4 numbers, depending on the domainname, its length and complexity.
proc lister
usage: p
proc killer
usage: p patt [signal]
uses only ps, grep, sed, printf and kill
no need for pgrep/pkill (not part of early UNIX)
_p(){
ps ax \
|grep $1 \
|sed '
/grep.'"$1"'/d' \
|while read a;do
printf ${a%% *}' ';
printf "${a#* }" >&2;
printf '\n';
done;
}
p(){
case $# in
0)
ps ax |grep .|less -iE;
;;
1)
_p $1;
;;
[23])
_p $1 2>/dev/null \
|sed '/'"$2"'/!d;
s,.*,kill -'"${3-15}"' &,'|sh -v
;;
esac;
}
alas, can't get this under 255 chars.
flatcap?
proc lister
usage: p
proc killer
usage: p patt [signal]
uses only ps, grep, sed, printf and kill
no need for pgrep/pkill (not part of early UNIX)
_p(){
ps ax \
|grep $1 \
|sed '
/grep.'"$1"'/d' \
|while read a;do
printf ${a%% *}' ';
printf "${a#* }" >&2;
printf '\n';
done;
}
p(){
case $# in
0)
ps ax |grep .|less -iE;
;;
1)
_p $1;
;;
[23])
_p $1 2>/dev/null \
|sed '/'"$2"'/!d;
s,.*,kill -'"${3-15}"' &,'|sh -v
;;
esac;
}
alas, can't get this under 255 chars.
flatcap?
In bash, this turns on auto cd. If a command is just a directory name, it cd's into that directory.
Alias a single character 'b' to move to parent directory. Put it into your .bashrc or .profile file.
Using "cd .." is one of the most repetitive sequence of characters you'll in the command line. Bring it down to two keys 'b' and 'enter'.
It stands for "back"
Also useful to have multiple:
alias b='cd ../'
alias bb='cd ../../'
alias bbb='cd ../../../'
alias bbbb='cd ../../../../'
In this example, the command will recursively find files (-type f) under /some/path, where the path ends in .mp3, case insensitive (-iregex).
It will then output a single line of output (-print0), with results terminated by a the null character (octal 000). Suitable for piping to xargs -0. This type of output avoids issues with garbage in paths, like unclosed quotes.
The tr command then strips away everything but the null chars, finally piping to wc -c, to get a character count.
I have found this very useful, to verify one is getting the right number of before you actually process the results through xargs or similar. Yes, one can issue the find without the -print0 and use wc -l, however if you want to be 1000% sure your find command is giving you the expected number of results, this is a simple way to check.
The approach can be made in to a function and then included in .bashrc or similar. e.g.
count_chars() { tr -d -c "$1" | wc -c; }
In this form it provides a versatile character counter of text streams :)
This command explains how to manage some asynchronous PID in a global process.
The command uses 4 processes in a global process. The asynchronous scripts are simulated by a time.sh script
more infos :
http://code-esperluette.blogspot.fr/2012/03/bash-gestion-de-processus-asynchrones.html
It's easier then the listed command, I'm thinking. but doesn't matter much--its closer to personal preference really.
Search for files and list the 20 largest.
find . -type f
gives us a list of file, recursively, starting from here (.)
-print0 | xargs -0 du -h
separate the names of files with NULL characters, so we're not confused by spaces
then xargs run the du command to find their size (in human-readable form -- 64M not 64123456)
| sort -hr
use sort to arrange the list in size order. sort -h knows that 1M is bigger than 9K
| head -20
finally only select the top twenty out of the list
This works in combination with http://www.commandlinefu.com/commands/view/10496/identify-exported-sonames-in-a-path as it reports the NEEDED entries present in the files within a given path. You can then compare it with the libraries that are exported to make sure that, when cross-building a firmware image, you're not bringing in dependencies from the build host.
The short version of it as can be seen in the same output is
scanelf -RBnq -F "+n#f" $1 | tr ',' '\n' | sort -u
This provides a list of shared object names (sonames) that are exported by a given tree. This is usually useful to make sure that a given required dependency (NEEDED entry) is present in a firmware image tree.
The shorter (usable) version for it would be
scanelf -RBSq -F "+S#f"
But I used the verbose parameters in the command above, for explanation.
This let's you find out the total packages that have available upgrades. Usefull if you want to check or show the total available upgrades on your system.
Bash snippet to force GNU/Linux keyboard settings, layout and configuration.
Usefull when some GNU/Linux distributions such as *Ubuntu's store only limited configation options due to demonstration purposes on LiveUSB or Live persistent devices.
Overcomes the English QWERTY to French AZERTY settings failure.
Code bash en ligne de commande pour forcer l'adoption du clavier AZERTY sur les cl? USB bootable en Ubuntu.
A timeout is great, but what if the command is taking longer than expected because it's hung up or ran into some other problem? That's where the -k option comes in. Run "some_command" and timeout after 30s. If the command is still running after 1 minute, it will receive a kill signal.
Write script or commands in notepad/Editplus/MS word etc, copy the contents, type the above command and click on enter now, paste by right click-ing the mouse. Entire contents in the clip-board gets pasted now again click on Enter to go to new line/next line. Press Ctrl+D to close/save the file. Not always required to vi to create a new file.
Emulate (more or less) Git equivalent of
git log --format='tformat:%h %an (%cr) %s'