Tag Archive for: Bash

How to find where things are installed in Linux?

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You just need to use which command, for example lets find the installation path for Node.js

which node

This will return in my case:

/home/myusername/n/bin/node

Best way to install Node.js and NPM

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Node.js strongly recommend using a Node version manager like n to install Node.js and npm. They do not recommend using a Node installer, since the Node installation process installs npm in a directory with local permissions and can cause permissions errors when you run npm packages globally.

Install n directly from Github:

curl -L https://bit.ly/n-install | bash

Then check your versions (remember than node comes with npm)

node --version && npm --version

Note: if you are already having problems, first remove everything related with Node.js and NPM

Resize a bunch of images at the same time using a Bash loop

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You can take advantage of Bash and ImageMagick to quickly do processing of many images.

for file in *.jpg; do convert $file -resize 1000 resized-$file; done

But it could be even easier using the command mogrify from the same library:

HOW TO RESIZE MULTIPLE IMAGES AT ONCE

How to copy all your Node projects to your external drive?

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Use rsync and exclude node_modules:

rsync -rv --exclude=node_modules my_projects /media/my_name/Seagate\ Expansion\ Drive/

-rv stand for recurse into directories and increase verbosity (see more info while copying)

Renaming Files in a folder to Sequential Numbers with a Prefix

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First of all, we have to order our files using ls -v and concatenate them to a standar output with cat -n. From this ouput we read the sequence (n) and the name of each file (f). Finally, we rename the files using mv, adding a prefix and the sequence (n)

ls -v | cat -n | while read n f; do mv "$f" "prefix$n.jpg"; done

If we want to add a zero pad (p) to our sequence (n) we can do it easily with printf.

ls -v | cat -n | while read n f; do printf -v p %03d $n; mv "$f" "prefix$p.jpg"; done