💻 Terminal Snippets

Variables

Strip the directory path from a shell variable string and leave the last part of the path (the filename)

$ FILE=${PATHTOFILE##*/}

Strip the file name from a shell variable string and leave the dir part of the path

$ DIR=${PATHTOFILE%/*}

Ediff shortcuts

Ediff shortcuts expand

a - apply changes from buffer A
b - apply changes from buffer B
d - keep both variants (A+B)
n - show next changes
p - show previous changes
r - recover the original difference region in buffer C
C-x o - change focused buffer window
v - scroll bottom
M-v - scroll up
q - end ediffing

---

$ base64

$ base64 -i IN_FILE_PATH -o OUT_FILE_PATH

Examples

$ base64 -i CertificateSigningRequest.certSigningRequest -o encodedbase64.txt

Encode string

 $ base64 -D <<< STRING

`base64 <<< LS0tLS1CRUdJTiBDRVJUSUZJ`

`$ base64 -D <<< STRING`
Decode string<br>

base64 -D <<< LS0tLS1CRUdJTiBDRVJUSUZJ== > file.bin

---

$ convert

Resize the image
$ convert image.png -resize 33% resized.png

---

$ echo

List all files matching pattern in current directory

 $ echo *.txt
 $ echo .*

---

$ git

Clean up submodules

$ git submodule foreach --recursive git clean -xfd
$ git submodule update -f --init --recursive --remote

Cherry pick diffs which are contained only in the ANY_BRANCH

$ git cherry -v master ANY_BRANCH > only-feature-chages.txt
$ git cherry-pick 64f0e89e718aa034704c5895f9de858afae9da97 f415a7d8c1599021761bab852109ef6389918...
$ git status
$ git cherry-pick --continue

Git find "string" in the history of diffs

$ git log -p -S string_for_searching

Git print diff between mybranch and master in the file 'myfile.cs'

$ git diff mybranch..master -- myfile.cs

Find the file in the history

$ git log --all --name-status  -- "**/filename.*"

Show the file changes in the commit

$ git show <SHA> -- <path-to-file>

Restore the file in the working copy

$ git checkout <SHA>^ -- <path-to-file>

Apply reverted changes from a commit

$ git show <SHA> -- <path-to-file> | git apply -3 --whitespace=fix -R

Add custom ssh identity file to the repository

$ git config core.sshCommand "ssh -i ~/.ssh/not_default_id_rsa -F /dev/null"

Log all particular file commits

$ git log --follow -- FILE_PATH

Revert 3 last commits in with one commit

$ git revert --no-commit HEAD~3..

---

$ hexdump

Generate 16 hex bytes

hexdump -vn16 -e'4/4 "%08X" 1 "\n"' /dev/urandom

Bash

Files editing

Display file changes in real time
$ tail -f FILE
Remove new line and escape " symbols in the file
$ cat ORIGINFILE.TXT | tr -d '\n' | sed 's/"/\\"/g' > NEWFILE.TXT
Find a string recursively at path
$ grep -ir SEARCHABLE_STRING PATH
$ grep -A NUMBER_OF_LINES_AFTER -ir SEARCHABLE_STRING PATH
Create a file from hex string
$ writehex 8ade18f6 00000001 00000000 51aabd81 > FILENAME.EXT
Сount characters in string
$ echo 'abc...1235abc..' | wc -c

$ zip

$ zip -er ZIP.zip file1 dir1 file2 - Zip files with password protecting

zip files in directory with the same name as parent dir

$ zip -erv "$(basename `pwd`).zip" production.*
$ Enter password:
$ Verify password:
$ rsync -v "$(basename `pwd`).zip" USER_NAME@SERVER:PATH && rm -rvf "$(basename `pwd`).zip"
$ Password:

$ swiftc

Compilte swift file with generating dSym file
$ swiftc -g file.swift
Run executable using lldb debugger
$ lldb file
Load dSym file
(lldb) add-dsym <PathTo.dSYM>
Print backtrace
(lldb) thread backtrace

---

$ find

Find files matched pattern *.ipa and extract to directory named filename.unz
$ find . -name '*.ipa' -exec sh -c 'unzip -d `basename {}`.unz {}' \;
Find files with matched patterh *.txt and copy to CGL-28825 directory
$ find ./UnitTests/ -name '*.txt' -exec sh -c 'cp {} CGL-28825/{}' \;
Find duplicated files in the directory
$ find . ! -empty -type f -exec md5 {} + | sort | uniq -d
Find in current folder the folders that were modified 182 days ago and delete them
$ find ./ -maxdepth 1 -type d -ctime +182 -exec rm -rfv {} \;
Find in current folder PNG images and remove alpha channel. Adds white color to background. Overwrites!
$ find . -name '*.png' -exec sh -c 'convert {} -background white -alpha remove -alpha off {}' \;
Find all Info.plist files and add new boolean false value
$ find ./ -name Info.plist -exec sh -c '/usr/libexec/PlistBuddy -c "Add :test bool false" {}' \;
$ find ./ -name Info.plist -exec sh -c '/usr/libexec/PlistBuddy -c "Add :my_key string \"\"" {}' \;
Find example
$ find ./ -type f -name '*.xib' -exec sed -i '' -e 's/<device[a-z=\"0-9_ ]*\/>/<device id=\"appleTV\" appearance=\"light\"\/>/g' {} +
Resize *.png images to size 800x600 and append to new file suffix 800x600.png
$ find ./ -name '*.png' -exec sh -c 'convert {} -resize 800x600! {}%.*_800x600.png' \; Find in Info.plist file and print 1 line After
$ find ./ios/ -name 'Info.plist' -exec sh -c 'grep -A 1 -ir receiver_id {}' \;
Find unique files in directory and copy in another
$ find ./ -type f -exec md5sum {} + | sort | awk '!c[substr($0, 1, 32)]++' | awk '{print $2}' | xargs -I _ cp _ another_dir
Find file in the current directory which contains the multiple strings STR1,STR2,STR3
$find ./ -type f -exec grep -l 'STR1' {} \; | xargs grep -l 'STR2' | xargs grep -l 'STR3'

---

$ ls

list files in one line
$ ls | tr "\n" " "

---

$ jq

Remove new lines from json
$ jq -c .
Pretty print JSON
$ jq '.'

---

$ sed

Find all *.txt files in dir and execute sed without backuping

$ find ./UnitTests/ -type f -name '*.txt' -exec sed -i '' -e 's/video_url_android/dash/g' {} +

Extract minor number from version

$ echo '1.2.3' | sed 's/\([0-9]\).[0-9].[0-9]/\1/'

Extract substring "Bench press" from a string "title": "Bench press"

$ echo '"title": "Bench press"' | sed -ne 's/"title": \([a-z]+\)*//p'

[[:space:]]*	match the whitespace characters <tab> and <space>

Extract version from podspec file

$ sed -rn "s/.*([0-9]+\.[0-9]+\.[0-9]+).*/\1/p" [FILE].podspec

Replace string from the stdin input

$ sed 's/\&/\&/g'

Replace digits A0 to "A0",

$ pbpaste| sed 's/\([0-9A-F][0-9A-F]\) /"\1",/g'

$ pbpaste| sed 's/\([0-9A-F]\{2,3\}\)[[:space:]]\{0,1\}/"\1",/g'

Convert md5 sum string to list of bytes in hex format

md5 -q Tests/Resources/1Mb | sed 's/\([0-9a-z][0-9a-z]\)/0x\1,/g'

---

$ top

Run top in non-interactive(batch) mode
$ top -l 1

---

$ clang

Compile single main.m file to executable prog
$ clang -fobjc-arc main.m -o prog1

---

$ printf

Tool for formatted output
$ printf '%-10.10s = %4.2f\n' 'Gigahertz' 1.92735

---

$ curl

Download and find and count occurances of regex_pattern in response (by adding new line \\\n)

$ curl  -v --silent 'http://awesome.com' 2>&1 | sed $'s/regex_pattern/regex_pattern\\\n/g' | grep -c 'regex_pattern'

An example with query parameters

curl -X POST -H "Accept: application/json" -H "Authorization: Basic xxxxxxxx" -H "Content-Type: application/x-www-form-urlencoded" --data          'grant_type=clone&refresh_token=xxx-xxx&scope=client'  'https://SERVER_URL'

---

$ grep

Extract substring from string:

$ grep -o -E '^[H](H|T|t)+-[0-9]{4}'

Extract 123 from versionCode 123

$ cat build.gradle | grep 'versionCode ' | grep -o -E '[0-9]+'

Extract "1.2.3" from versionName "1.2.3"

$ cat build.gradle | grep 'versionName ' | grep -o -E '\"[0-9].[0-9].[0-9]\"'

Extract URL from file

$ grep -o -E 'https://url.com/[?=;&_a-z0-9-]+' ../photos.txt

Exclude directories during search

$ grep --exclude-dir=Pods --exclude-dir=fastlane -ir 'https://' ./

Find multiple patterns

$ grep -e 'pattern1' -e 'pattern2' file

---

$ nc

Establish socket connection

nc IP PORT 

---

$ telnet

Establish socket connection

telnet IP PORT 

---

$ nettop

Listen the socket connection created by process with PID

nettop -n -p PID

---

$ venv

Create python virtual envrironment

python3 -m venv venv

Activate virtual environment

source env/bin/activate

Stop virtual environment

deactivate

---

$ rsync

Sync images(png, PNG, jpg, JPG) in 2 local folders

$  rsync -r --include="*.[Jj][Pp][Gg]" --include="*.[Pp][Nn][Gg]" --include="*/" --exclude="*" -av --progress FromDir1/ ToDir2/

Formatting

Pretty print JSON string

$ echo '{"foo": "lorem", "bar": "ipsum"}' | python -m json.tool

echo $(python3 -c "import sys,json; print(json.load(sys.stdin)['fields']['summary'])" <<< ${RESPONSE})

Pretty print XML string

$ echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' | xmllint --format -

Emacs

select region then M-| pbcopy RET - copy from Emacs to OS X clipboard
M-x hexl-find-file - editing binary files (delete-window)
M-x hexl-mode - translate an existing buffer into hex

Git-Emacs

m - mark the file the cursor is on ATM
M - mark all files in buffer
u/DEL - unmark file below/above
R - resolve conflicts during merge
a - add file to repository
r - remove file
i - add file to ignore list
c - commit
U - Undo -> revert file
l - see log file
g - refresh the status buffer
q - quit status buffer
? - get help!

Emacs-Magit

Emacs-Magit

M-x magit-process-buffer - to show the output of recently run git commands
M-x magit-section-cycle-diffs - to expand all diffs
l-l b-b - checkout selected commit in history

Midnight Commander

ESC+o - open directory in another panel

Xcode. Setup template commands

Rename class prefix occurances in the folder.

$ find ./ -type f -exec sed -i "" -e 's/CLConfirmLogout/___VARIABLE_productName:identifier___/g' {} \;

Xcode debugger

Update view on debug

// stash a view (0x7f84c74ca870 address)
(lldb) e UIView *$cell = (UIView *)[0x7f84c74ca870 superview]
// set a new frame
(lldb) e (void)[$cell setFrame:(CGRect){0.f, 324.f, 10.f, 54.f}]
// set a new frame
(lldb) e (void)[$cell setFrame:(CGRect){0.f, 324.f, 10.f, 54.f}]
// update
(lldb) caflush frame

Examining Variables

Show the contents of the local variable bar formatted as hex.

(lldb) frame variable --format x bar
(lldb) fr v -f x bar

FFMPEG

Cut video of [duration]

$ ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy out.mp4

Create gif image from movie

$ ffmpeg -ss 30 -t 3 -i input.mp4 -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 output.gif

• This example will skip the first 30 seconds (-ss 30) of the input and create a 3 second output (-t 3).
• fps filter sets the frame rate. A rate of 10 frames per second is used in the example.
• scale filter will resize the output to 320 pixels wide and automatically determine the height while preserving the aspect ratio. The lanczos scaling algorithm is used in this example.
• palettegen and paletteuse filters will generate and use a custom palette generated from your input. These filters have many options, so refer to the links for a list of all available options and values. Also see the Advanced options section below.
• split filter will allow everything to be done in one command and avoids having to create a temporary PNG file of the palette.
• Control looping with -loop output option but the values are confusing. A value of 0 is infinite looping, -1 is no looping, and 1 will loop once meaning it will play twice. So a value of 10 will cause the GIF to play 11 times. More info http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html