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Stop Flash from tracking everything you do.
Brute force way to block all LSO cookies on a Linux system with the non-free Flash browser plugin. Works just fine for my needs. Enjoy.

Check how far along (in %) your program is in a file
Say you're started "xzcat bigdata.xz | complicated-processing-program >summary" an hour ago, and you of course forgot to enable progress output (you could've just put "awk 'NR%1000==0{print NR>"/dev/stderr"}{print}'" in the pipeline but it's too late for that now). But you really want some idea of how far along your program is. Then you can run the above command to see how many % along xzcat is in reading the file. Note that this is for the GNU/Linux version of lsof; the one found on e.g. Darwin has slightly different output so the awk part may need some tweaks.

Update a tarball
This will update the tarball, adding files that have changed since the last update. This assumes that the tarball is in the same directory as the files being archived. N.B. This command can't be used on compressed tarballs. N.B. This will add the updated files to the tarball, so that the tarball will have two versions of each file. This will make the tarball larger, but doesn't have any other significant effect.

Most Commonly Used Grep Options
This is very helpful to place in a shell startup file and will make grep use those options all the time. This example is nice as it won't show those warning messages, skips devices like fifos and pipes, and ignores case by default.

Read aloud a text file in Ubuntu (and other Unixes with espeak installed

See why a program can't seem to access a file
Sometimes a program refuses to read a file and you're not sure why. You may have display_errors turned off for PHP or something. In this example, fopen('/var/www/test/foo.txt') was called but doesn't have read access to foo.txt. Strace can tell you what went wrong. E.g., if php doesn't have read access to the file, strace will say "EACCESS (Permission denied)". Or, if the file path you gave doesn't exist, strace will say "ENOENT (No such file or directory)", etc. This works for any program you can run from the command-line, e.g., strace python myapp.py -e open,access... Note: the above command uses php-cli, not mod_php, which is a different SAPI with diff configs, etc.

Clear history

Show numerical values for each of the 256 colors in bash
I like the other three versions but one uses nested loops and another prints every color on a separate line. Both versions fail to reset colors before giving the prompt back. This version uses the column command to print a table so all the colors fit on one screen. It also resets colors back to normal before as a last step.

Find usb device
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

Find the package that installed a command


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