G-α - Unix & alike

Terminal Useful Commands

 

# ==== MISC

diff -w [file1] [file2] > [diffFile]

open -a [application] [file]

echo -e "first_line \n second_line" (with -e); 

ssh -v [username]@[firewall] -t ssh [username]@[internal] 

sshfs [username]@hostname:[path_to_remote_dir]  [path_to_local_dir]

screen -S [name_of_background_screen]; 

control-a-d (escape screen mode); 

control-a-[ (enable scrollback mode)

curl "[url_address]" (linux's wget dude)

echo "hello, world!" | tee path_to_file ('tee' command to pipe standard output to somewhere)

iconv -f original_encoding -t new_encoding original_file > new_file (change charset)

file -I <filename> (know encoding)

nmap -n -sP 10.0.0.0/24 (ping for several hosts)

top -d [number_of_seconds] (check processes passing delay)

awk '{print FNR "\t" $0}' path_to_file.txt | open -f (add pseudo linenumbers into TextEdit; use opt+drag for text selection) 
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# ==== HOTKEYS


^+A: go to beginning of line
^+E: go to end of line
^+U: clean up entire line
^+y: recall the deleted command
^+K: delete forward cursor position
^+W: delete backward cursor position
^+C: cancel command
^+L: clear entire prompt
^+R: search on history; type again to run through history 

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# ==== Sun Grid Engine essentials
qsub

qdel pid; -u username

qstat -f; -explain; -j; -j jobid; -F [attributes] 

qhost -j

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macOS keyboard fast symbols

 

Fast symbols with option button + keys on Mac:
opt + 1,2,3,4,5,6,7,8,9,0 --> ¡,™,£,¢,∞,§,¶,≤,•,ª,º
opt + q,w,e,r,t,y,u,i,o,p --> œ,∑,´,®,≤,†,¥,¨,ˆ,ø,π
opt + a,s,d,f,g,h,j,k,l --> å,ß,∂,≤,ƒ,≤,©,≤,˙,∆,˚,¬
opt + z,x,c,v,b,n,m --> Ω,≈,ç,√,∫,˜,µ
opt + = --> ≠
opt + [, ], \ --> “,‘,«
opt + ;, ' --> …,Æ
opt + , ,. ,/ --> ≤,≥,÷- 

opt + shift + [key] --> several
opt + shift + k --> 
opt + shift + 2 --> €
opt + shift + 8 --> °
opt + shift + v --> ◊

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Misc

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  • How to record voice over: using command say to read file and output as audio:
 
say -f file.txt -o output_file.aiff -r <rate_in_words_per_minute> -v [alex, bruce, luciana, etc]

.zshrc and .zshenv

  • macOS is now using Z Shell as default shell.
  • Add preferences to ~/.zshrc;. Then update with source ~/.zshrc.
  • If a .bash_profile exists, the quick way to get things working as before is to create a .zshenv and pull back current settings with echo source ~/.bash_profile > ~/.zshenv && source ~/.zshenv; see here.

Convert image files in batch mode

  • Replaces X,Y by PNG/JPEG/TIF (problem with EPS?)
 
for i in *; do sips -s format X $i --out $i.Y; done
 
brew install imagemagick; magick convert A.jpg A.png

Create password-protected zip file

 
zip -er file.zip folder_to_zip/

Jekyll installation workaround on Apple M1 chips

Jekyll is a good backend for building static sites. However, in the new Apple’s M1 chips, some problems with architecture are alleged.

A workaround to have Jekyll working on these machines is:

  • Not using macOS’s embedded ruby, but install it from homebrew. Follow these steps
  • Since this new ruby is keg-only and not symbolically linked, add it to .zshenv (the .gem executable is required) to have:
 
export PATH="/opt/homebrew/opt/ruby/bin:$PATH"
export PATH="$HOME/.gem/ruby/3.1.0/bin:$PATH"
  • Restart the shell and check if ruby -v points to the ruby version installed from brew.
  • Install jekyll, bundler and webrick (necessário) localmente:
 
gem install --user-install bundler, jekyll, webrick

Convert .m4a to .mp3

  • Install ffmpeg with brew install ffmpeg
  • Use ffmpeg -i in.m4a -codec:a libmp3lame -qscale:a 1 out.mp3

Remove printing restrictions on PDF

  • Install qpdf with brew install qpdf
  • Use qpdf --decrypt in.pdf out.pdf

Command line PDF to TXT conversion

  • Install: brew install xpdf
  • Usage: pdftotext -enc UTF-8 in.pdf out.txt

Command line PDF merger

  • See pdfunite. Perhaps, it conflicts with xpdf because of poppler.