(relies on 'imagemagick') This command will convert all .pdf files in a directory into a 800px (wide or height, whichever is smaller) image (with the aspect ratio kept) .jpg. If the file is named 'example1.pdf' it will be named 'example1.jpg' when it is complete. This is a VERY worthwhile command! People pay hundreds of dollars for this in the Windows world. My .jpg files average between 150kB to 300kB, but your's may differ. Show Sample Output
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him Show Sample Output
While editing a source file in vim, or using vimdiff to compare two or more files, the ':TOhtml' command can be used to export each buffer as an html file, including syntax highlighting and vimdiff colorization. If you are in insert mode in vim, you will have to type :TOhtml This will open a new buffer filled with html, which you can then save.
connects to host via ssh and displays the live transfer speed, directing all transferred data to /dev/null needs pv installed Debian: 'apt-get install pv' Fedora: 'yum install pv' (may need the 'extras' repository enabled) Show Sample Output
Creates a full snapshot of your current vim session, including tabs, open buffers, cursor positions, everything. Can be resumed with vim -S . Useful for those times when you HAVE to close vim, but you don't want to lose all your hard-opened buffers and windows. The ! will cause vim to overwrite the file if it already exists. It is not necessary, but useful if you frequently save to the same file (like session.vim or something).
(also works on Ubuntu) Copies the 'install,' 'hold,' 'deinstall' and 'purge' states of packages on the remote machine to be matched on the local machine. Note: if packages were installed on the local machine that were never installed on the remote machine, they will not be deinstalled by this operation.
the -x option is for binding to a shell command
Of course it requires import command, from imagemagick tools, but it's simpler to type, and imagemagick is usefull anyway.
Run the alias command, then issue
ps aux | head
and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand.
${LINES:-`tput lines 2>/dev/null||echo -n 12`}
Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the deafault of 12 (-2 = 10).
The default for HEAD is to output the first 10 lines, this alias changes the default to output the first x lines instead, where x is the number of lines currently displayed on your terminal - 2. The -2 is there so that the top line displayed is the command you ran that used HEAD, ie the prompt.
Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( https://www.askapache.com/linux/bash-power-prompt/ )
275MB/748MB
[7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~
In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.
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PDF files are simultaneously wonderful and heinous. They are wonderful in being ubiquitous and mostly being cross platform. They are heinous in being very difficult to work with from the command line, search, grep, use only the text inside the PDF, or use outside of proprietary products. xpdf is a wonderful set of PDF tools. It is on many linux distros and can be installed on OS X. While primarily an open PDF viewer for X, xpdf has the tool "pdftotext" that can extract formated or unformatted text from inside a PDF that has text. This text stream can then be further processed by grep or other tool. The '-' after the file name directs output to stdout rather than to a text file the same name as the PDF. Make sure you use version 3.02 of pdftotext or later; earlier versions clipped lines. The lines extracted from a PDF without the "-layout" option are very long. More paragraphs. Use just to test that a pattern exists in the file. With "-layout" the output resembles the lines, but it is not perfect. xpdf is available open source at http://www.foolabs.com/xpdf/
That command installs "most" and make this command as the default man reader. The "most" works like "less" (the current man reader), but it render colors for manpages and may do more things. Read "man most". You can see a preview here: http://www.dicas-l.com.br/dicas-l/20090718.php
What happens here is we tell tar to create "-c" an archive of all files in current dir "." (recursively) and output the data to stdout "-f -". Next we specify the size "-s" to pv of all files in current dir. The "du -sb . | awk ?{print $1}?" returns number of bytes in current dir, and it gets fed as "-s" parameter to pv. Next we gzip the whole content and output the result to out.tgz file. This way "pv" knows how much data is still left to be processed and shows us that it will take yet another 4 mins 49 secs to finish. Credit: Peteris Krumins http://www.catonmat.net/blog/unix-utilities-pipe-viewer/ Show Sample Output
cat? dd? RTFM
You got some results in two variables within your shell script and would like to find the differences? Changes in process lists, reworked file contents, ... . No need to write to temporary files. You can use all the diff parameters you'll need. Maybe anything like $ grep "^>" is helpful afterwards.
Generated XML files often are poorly formatted. Use this command to properly indent and normalize the file in-place.
Create an AES256 encrypted and compressed tar archive.
User is prompted to enter the password.
Decrypt with:
openssl enc -d -aes256 -in <file> | tar --extract --file - --gzip
This is a very simple way to input a large number of seconds and get a more useful value in minutes and seconds. Avoids useless use of echo. Show Sample Output
You can use [n]> combined with >(cmd) to attach the various output file descriptors to be the input of different commands.
Continue with:
killall -CONT -m firefox
Suspends all Firefox Threads. Results in Zero CPU load.
Useful when having 100+ Tabs open and you temporarily need the power elsewhere.
Be careful - might produce RACE CONDITIONS or LOCKUPS in other processes or FF itself.
matching is case sensitive.
This command will tell lynx to read keystrokes from the specified file - which can be used in a cronjob to auto-login on websites that give you points for logging in once a day *cough cough* (which is why I used -accept_all_cookies).
For creating your keystroke file, use:
lynx -cmd_log yourfile
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