Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

Hide

News

2012-05-20 - test
test
2012-05-20 - test
test
2012-05-20 - test
test
2012-05-20 - Test tweets
YU not working?
Hide

Tags

Hide

Functions

Commands tagged jpeg

Commands tagged jpeg from sorted by
Terminal - Commands tagged jpeg - 5 results
find . -type f -name '*.jpg' -exec convert -quality 75 {} {} \;
2011-09-23 13:51:18
User: bobby_tables
Functions: find
0

Requires ImageMagick to be installed.

This command was stolen from @climagic on Twitter.

Probably a duplicate of command below, but this command uses slightly higher quality.

http://www.commandlinefu.com/commands/view/707/compress-images-using-convert-imagemagick-in-a-bulk

jpegtran -optimize -outfile temp.jpg <JPEG> && mv temp.jpg "$_"
2011-07-24 08:55:46
User: h3xx
Functions: mv
Tags: jpeg
0

You can also save EXIF information by copying it to temp.jpg:

jpegtran -optimize -outfile temp.jpg <JPEG> && jhead -te temp.jpg "$_" && mv temp.jpg "$_"
pdfimages -j foo.pdf bar
2011-07-07 17:18:36
User: lucasrangit
Tags: pdf jpeg
2

This will extract all DCT format images from foo.pdf and save them in JPEG format (option -j) to bar-000.jpg, bar-001.jpg, bar-002.jpg, etc.

Inspired by http://stefaanlippens.net/extract-images-from-pdf-documents

find . -name "*jpg" -exec jpeginfo -c {} \; | grep -E "WARNING|ERROR"
2009-06-03 22:08:48
User: vincentp
Functions: find grep
9

Finds all corrupted jpeg files in current directory and its subdirectories. Displays the error or warning found.

The jpeginfo is part of the jpeginfo package in debian.

Should you wish to only get corrupted filenames, use cut to extract them :

find ./ -name *jpg -exec jpeginfo -c {} \; | grep -E "WARNING|ERROR" | cut -d " " -f 1
for i in *jpg; do jpeginfo -c $i | grep -E "WARNING|ERROR" | cut -d " " -f 1 | xargs -I '{}' find /mnt/sourcerep -name {} -type f -print0 | xargs -0 -I '{}' cp -f {} ./ ; done
2009-05-07 00:30:36
User: vincentp
Functions: cp cut find grep xargs
0

Find all corrupted jpeg in the current directory, find a file with the same name in a source directory hierarchy and copy it over the corrupted jpeg file.

Convenient to run on a large bunch of jpeg files copied from an unsure medium.

Needs the jpeginfo tool, found in the jpeginfo package (on debian at least).