Commands by mikhail

Commands by mikhail (15)

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Shows a specific process memory usage
This is sample output - yours may be different.
1

mem() { ps -C "$1" -O rss | awk '{ count ++; sum += $2 }; END {count --; print "Number of processes:\t",count; print "Mem. usage per process:\t",sum/1024/count, "MB"; print "Total memory usage:\t", sum/1024, "MB" ;};'; }

mikhail · 2022-01-23 16:14:24 492
Display disk partition sizes

Use lsbk (list block) and jq (to manipulate a JSON on the command line) to display partition information: Show Sample Output
This is sample output - yours may be different.
```
["loop0","55.5M"]
["loop1","156M"]
["loop2","32.3M"]
["zram0","4G"]
["nvme0n1","476.9G"]
```
2

lsblk --json | jq -c '.blockdevices[]|[.name,.size]'

mikhail · 2021-12-22 22:31:07 330
Monitor memory without top or htop

It repeats a command, such as free, every five seconds and highlights the differences
This is sample output - yours may be different.
1

watch -n 5 -d '/bin/free -m'

mikhail · 2021-12-22 22:28:59 443
Find failures with journalctl

Sometimes things break. You can find the most recent errors using a combination of journalctl, along with the classic tools sort and uniq Show Sample Output
This is sample output - yours may be different.
```
898172 "/usr/bin/dockerd"
    752 "/usr/local/sbin/node_exporter"
     30 "/usr/bin/gnome-shell"
     26 "/usr/bin/cat"
     22 "/usr/libexec/gsd-media-keys"
[...]
```
1

journalctl --no-pager --since today --grep 'fail|error|fatal' --output json | jq '._EXE' | sort | uniq -c | sort --numeric --reverse --key 1

mikhail · 2021-12-22 22:27:17 284
Share a file quickly using a python web server

Raise your hand if you haven't used this at least once to share a directory quickly
This is sample output - yours may be different.
3

cd $mydir && python3 -m http.server 8888

mikhail · 2021-12-22 22:24:37 302
Apply a command on files with different names

The shell {} operator is great for this. Here's an example with three directories enclosed in {}:
This is sample output - yours may be different.
0

mkdir -p -v /home/user/tmp/{dir1,anotherdir,similardir}

mikhail · 2021-12-22 22:22:51 441
extract email addresses from some file (or any other pattern)
This is sample output - yours may be different.
1

grep -Eio '([[:alnum:]_.-]{1,64}@[[:alnum:]_.-]{1,252}?\.[[:alpha:].]{2,6})'

mikhail · 2020-07-22 22:40:33 191
Slugify: converts strings in any language into Slugs (friendly names to use in URLs and filenames)

Slug the part of an URL which identifies a page using human-readable keywords. Slugs are used to construct friendly URLs (often for permalinks) that are easy to type, descriptive, and easy to remember. Show Sample Output
This is sample output - yours may be different.
```
function slugify() { tr '[:upper:]' '[:lower:]' <<< "$(sed -z -r -e 's~[^[:alnum:]]+~ ~g' -e 's~ (he|here|how|it|she|there|what|when|where|who) s ~ \1 is ~gi' -e 's~^ *~~;s~ *$~~' -e 's~ +~-~g' - <<< " $(iconv -c -t ASCII//TRANSLIT//IGNORE - <<< " $@ " ) ")"; }


# testing special characters and spaces:
slugify " Test: µÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝß      and àáâãäåæçèéêëìíîïðñòóôõöøùúûüýÿ ";

# output:
test-uaaaaaaaeceeeeiiiidnoooooouuuuyss-and-aaaaaaaeceeeeiiiidnoooooouuuuyy
```
1

function slugify() { tr '[:upper:]' '[:lower:]' <<< "$(sed -z -r -e 's~[^[:alnum:]]+~ ~g' -e 's~^ *~~;s~ *$~~' -e 's~ +~-~g' - <<< "$(iconv -c -t ASCII//TRANSLIT//IGNORE - <<< "$@" )")"; }

mikhail · 2019-06-08 17:45:57 43
WSL: Change the current directory converting a Windows path to a Linux Path

The Windows Subsystem for Linux (WSL) is a compatibility layer for running binary Linux executables natively in Windows. A folder such as "C:\Program Files (x86)\Common Files" is represented as "/mnt/c/Program Files (x86)/Common Files". This function allows you to change the current directory to a Windows folder. Show Sample Output
This is sample output - yours may be different.
```
function _cd() { local dir="$(sed -e 's~$[a-z]$:~/mnt/\L\1~gi' <<< "${*//'\'/"/"}" )"; if [ -d "$dir" ]; then cd "$dir"; fi; }

# quotes are necessary:
_cd 'C:\Program Files (x86)\Common Files';

# result: cd '/mnt/c/Program Files (x86)/Common Files'
```
0

function _cd() { local dir; dir="$(sed -e 's~$[a-z]$:~/mnt/\L\1~gi' <<< "${*//'\'/"/"}" )"; if [ -d "$dir" ]; then cd "$dir" || exit; fi; }

mikhail · 2019-06-06 17:53:28 42
PHP7 - Fix incompatibility errors like: Parse error: syntax error, unexpected new (T_NEW) in file.php on line...

New objects cannot be assigned by reference. The result of the new statement can no longer be assigned to a variable by reference. Check the "Sample Output" example ("sample.php"). The Output of the above example in PHP 5: "Deprecated: Assigning the return value of new by reference is deprecated in sample.php on line 3". Output of the above example in PHP 7: "Parse error: syntax error, unexpected 'new' (T_NEW) in sample.php on line 3. Show Sample Output
This is sample output - yours may be different.
```
echo -e "<?php\nclass C {}\n\$c =& new C;\n?>" > sample.php
cat sample.php
<?php
class C {}
$c =& new C;
?>
busybox sh -c 'find "$(realpath ./)" -type f $ -iname "*.php" -or -iname "*.inc" $ -exec sed -i -r "s~=[[:space:]]*&[[:space:]]*new[[:space:]]+~= new ~gi" {} \; '
cat sample.php
<?php
class C {}
$c  = new C;
?>
```
0

find "$(realpath ./)" -type f $ -iname "*.php" -or -iname "*.inc" $ -exec sed -i -r "s~=[[:space:]]*&[[:space:]]*new[[:space:]]+~= new ~gi" {} \;

mikhail · 2019-05-29 18:20:45 39
Identifies the file types in a directory and adds or replaces their file extensions.

It tries to identify the file types in a directory and adds or replaces them with their appropriate extensions. Please, update the "file" tool before use it (last version: 5.37): https://github.com/file/file
This is sample output - yours may be different.
0

find "$(realpath .)" -type f -exec bash -c 'p="{}"; b="${p##*/}"; e=${b#"${b%.*}"}; e2=$(file -b -F="" --extension "$p"| awk -F/ '\''$1~/^\w+$/ {print $1} '\''); if [ "$e" != ".$e2" ] && [ ! -z $e2 ]; then mv "$p" "${p%$b}${b%$e}.$e2"; fi;' \;

mikhail · 2019-05-18 01:56:25 41
Remove scripts tags from *.html and *.htm files under the current directory
This is sample output - yours may be different.
0

find ./ -type f $ -iname '*.html' -or -iname '*.htm' $ -exec sed -i '/<script/,/<\/script>/d' '{}' \;

mikhail · 2019-05-10 23:27:12 153
stringContains: Determining if a String Contains a Substring

Show Sample Output
This is sample output - yours may be different.
```
function stringContains() { [ -z "${2##*$1*}" ] && [ -z "$1" -o -n "$2" ]; };

# Used like so
SRC_STRING="this is a sample string where TEST we want to check for the word 'TEST'"
if stringContains "TEST" "$SRC_STRING"; then
	echo "Found TEST in SRC_STRING"
else
	echo "Couldn't find TEST in SRC_STRING"
fi
```
2

function stringContains() { [ -z "${2##*$1*}" ] && [ -z "$1" -o -n "$2" ]; };

mikhail · 2019-04-12 20:51:27 35
Calculate the distance between two geographic coordinates points (latitude longitude)

The Haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. Show Sample Output
This is sample output - yours may be different.
```
# input (format: latitude1 longitude1 latitude2 longitude2) :

h -22.9077611 -43.1259322 -22.9121089 -43.2301558

# output:
10.6889

# So, the distance between -22.9077611 (latitude),-43.1259322 (longitude) and -22.9121089,-43.2301558 (latitude,longitude) is 10,688.9 meters (10.6889 kilometers)
```
3

h(){ echo $@|awk '{d($1,$2,$3,$4);} function d(x,y,x2,y2,a,c,dx,dy){dx=r(x2-x);dy=r(y2-y);x=r(x);x2=r(x2);a=(sin(dx/2))^2+cos(x)*cos(x2)*(sin(dy/2))^2;c=2*atan2(sqrt(a),sqrt(1-a)); printf("%.4f",6372.8*c);} function r(g){return g*(3.1415926/180.);}';}

mikhail · 2019-04-04 01:34:36 39
worse alternative to <ctrl+r>

worse alternative to ctrl+r: grep the history removing duplicates without sorting (case insensitive search). Show Sample Output
This is sample output - yours may be different.
```
head ~/.bash_history # history sample for reference:
echo "duplicate"
awk --help
echo "duplicate"
echo "ctrl+r is better"

# input:
memo echo

# output:
echo "duplicate"
echo "ctrl+r is better"
```
1

function memo() { awk '! seen[$0]++' <<< $(grep -i "$@" ~/.bash_history ); }

mikhail · 2019-04-04 00:54:43 37

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Look for English words in /dev/urandom

* to get the English dictionary: wget http://www.mavi1.org/web_security/wordlists/webster-dictionary.txt

Recursive cat - concatenate files (filtered by extension) across multiple subdirectories into one file

Useful if you have to put together multiple files into one and they are scattered across subdirectories. For example: You need to combine all .sql files into one .sql file that would be sent to DBAs as a batch script. You do get a warning if you create a file by the same extension as the ones your searching for. find . -type f -name *.sql -exec cat {} > BatchFile.txt \;

Create a DOS floppy image

mount with: mount -t msdos -o loop ./floppy.img /tmp/mnt

Find files containing string and open in vim

I often use "vim -p" to open in tabs rather than buffers.

cp the file

Copy the file with the given .extension at the source file's location. Eliminates the typing of long paths again and again.

Updating the status on identi.ca using curl.

identica is an open source social networking and micro-blogging service. Based on Laconica, a micro-blogging software package built on the OpenMicroBlogging specification. http://identi.ca/

list block devices

Shows all block devices in a tree with descruptions of what they are.

Resize an image to at least a specific resolution

This command will resize an image (keeping the aspect ratio) to a specific resolution, meaning the resulting image will never be smaller than this resolution. For example, if we have a 2048x1000 image, the output would be 1229x600, not 1024x600 or 1024x500. Same thing for the height, if the image is 2000x1200, the output would be 1024x614.

Automatically download Ubuntu 10.04 when available

Tested with 9.10 release. Choose whatever torrent client you prefer.

Quick HTML image gallery from folder contents with Perl

This includes a title attribute so you can see the file name by hovering over an image. Also will hoover up any image format - jpg, gif and png.

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