Computing

Mostly Linux terminal (zsh on my machines, bash/tcsh elsewhere)

command line (zsh / bash)

  • find files
    • by name
      find <location> -iname 'filename.ext' # accepts wildcards
      

      or zsh option

      ls -ld -- **/*name_fragment*
      
    • by type
      -find  <location> -type f -name ".conf"
      
  • search directory recursively for search expression
      grep --include\*.{extensions} -rnw 'home/folder/' -e 'pattern'
    
  • (zsh specific) Replace all instances of foo with bar in all files recursively
      sed -i -- 's/foo/bar/g' **/*(D.)
    
  • recursively delete all .git folders (before backing up to an external drive without backing up all thousands of annoying .pack files)
      ( find . -type d -name ".git" && find . -name ".gitignore" && find . -name ".gitmodules" ) | xargs rm -rf
    
  • zsh globbing loops
      for f in **/*.ext; do <command> $f; done
    
  • symlinks (both files and directories)
      ln -s <target> <link_name>
    
  • hard drive space
      df -H
    
  • chmod
      chmod +x script.sh
    
  • chown
      chown -R user:domain folder
    
  • scp (copy log files from ssh server to local directory)
      apoorva@age4.nber.org:apoorva/Do/\*.log ./
    
  • populate sensible gitignores
      'echo "*.csv\n*.dta\n*.ipynb_checkpoints" >> .gitignore'
    

convert

  • pngs into gif (for R/Python plots)
      convert -delay 45 -loop 0 *.png <gif-title>.gif
    
  • pdfs to jpgs
      for i in `ls *.pdf`; do convert -density 300 "$i" "${i%%.*}.png"; done
    
  • tsv to csv (hahvahd does tsv for some inexplicable reason)
    tr '\t' ',' < input.tab > output.csv
    

pdf operations

  • combine
    pdfunite in1.pdf in2.pdf out.pdf
    
  • slice large pdfs [either pdftk or qpdf]
    qpdf --empty --pages bigdoc.pdf 1-10 -- smalldoc.pdf
    

wget

  • match extension/pattern
    wget <site> -nd -np -l1 -r -v  -A "<pattern>*.<extension>"
  • mirror entire site
    wget -mkEpnp <site>

git

  • init new .gitignore with sensible defaults
    echo '*.csv\n*.dta\n*.ipynb_checkpoints' >> .gitignore
    
  • refresh repo after update to .gitignore
      git rm -r --cached . && git add .
    
  • remove current remote and add new remote
      git rm remote origin && git remote add origin <repo link>
    

conda / jupyter / ipython - conda cheatsheet

  • convert notebooks into scripts
      jupyter nbconvert --to script *.ipynb
    
  • activate environment
      source activate <env>
    
  • link pythonstartup file to default ipython profile
    ln -s ~/dotfiles/pythonstartup ~/.ipython/profile_default/startup/start.py
    
  • add environment to kernelspec after install so it shows up in Jupyter Notebook/Lab and Atom
    source activate myenv
    conda install ipykernel
    python -m ipykernel install --user --name myenv --display-name "New Environment"
    
  • export list of packages from current environment
      conda env export > requirements.txt
    
  • delete environment
      conda env remove --name <env-name>
    

pandoc - ref

  • generic
      pandoc -s <input file> -o <output file>
    
  • markdown to latex
      pandoc -s <md> -o <tex>
    
  • markdown to pdf with citations
      pandoc -s --bibliography biblio.bib --filter pandoc-citeproc CITATIONS -o example24a.html