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list files recursively by size

Copy file content to X clipboard
(only when vim has been compiled with +clipboard)

Find Duplicate Files (based on MD5 hash)
Calculates md5 sum of files. sort (required for uniq to work). uniq based on only the hash. use cut ro remove the hash from the result.

Colorize svn stat
Use color escape sequences and sed to colorize the output of svn stat -u. Colors: http://www.faqs.org/docs/abs/HTML/colorizing.html svn stat characters: http://svnbook.red-bean.com/en/1.4/svn-book.html#svn.ref.svn.c.status GNU Extensions for Escapes in Regular Expressions: http://www.gnu.org/software/sed/manual/html_node/Escapes.html

Brute force discover
Show the number of failed tries of login per account. If the user does not exist it is marked with *.

Robust expansion (i.e. crash) of bash variables with a typo
By default bash expands an unbound variable to an empty string. This can be dangerous, if a critical variable name (a path prefix for example) has a typo. The -u option causes bash to treat this as an error, and the -e option causes it to exit in case of an error. These two together will make your scripts a lot safer against typos. The default behaviour can be explicitly requested using the ${NAME:-} syntax. A (less explicit) variation: #!/bin/bash -eu

Watch how many tcp connections there are per state every two seconds.
slighty shorter

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Wait for file to stop changing
Here's a way to wait for a file (a download, a logfile, etc) to stop changing, then do something. As written it will just return to the prompt, but you could add a "; echo DONE" or whatever at the end. This just compares the full output of "ls" every 10 seconds, and keeps going as long as that output has changed since the last interval. If the file is being appended to, the size will change, and if it's being modified without growing, the timestamp from the "--full-time" option will have changed. The output of just "ls -l" isn't sufficient since by default it doesn't show seconds, just minutes. Waiting for a file to stop changing is not a very elegant or reliable way to measure that some process is finished - if you know the process ID there are much better ways. This method will also give a false positive if the changes to the target file are delayed longer than the sleep interval for any reason (network timeouts, etc). But sometimes the process that is writing the file doesn't exit, rather it continues on doing something else, so this approach can be useful if you understand its limitations.

Perl oneliner to print access rights in octal format
This prints file access rights in octal - useful when "stat" is unavailable.


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