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List all symbolic links in current directory that matches regexp
Perl alternative to list symlinks with a clumsy regexp filter: place the regex instead of he example 'libxml' and end it with a wildchar to see the results (previous cd on dir). Is it possible change the '-l' test for '-d' and it will search for directories. [Same applies for -x and -X. See $(perldoc -f -x) for more tests]. I use it quite often when dealing with shared libraries...

Day of the week of your birthday over the years.
Do you ever want to know which day of week was your birhday! Now you can check that with this command, just set your birh date at the beginning (My bday in the example) and the dates will be revealed. ;)

Chmod all directories (excluding files)
+ at the end means that many filenames will be passed to every chmod call, thus making it faster. And find own {} makes sure that it will work with spaces and other characters in filenames.

Adding Prefix to File name
Good old bracket expansion :-) For large numbers of files, "rename" will spare you the for-loop, or the find/exec...

Wait for file to stop changing
This loop will finish if a file hasn't changed in the last 10 seconds. . It checks the file's modification timestamp against the clock. If 10 seconds have elapsed without any change to the file, then the loop ends. . This script will give a false positive if there's a 10 second delay between updates, e.g. due to network congestion . How does it work? 'date +%s' gives the current time in seconds 'stat -c %Y' gives the file's last modification time in seconds '$(( ))' is bash's way of doing maths '[ X -lt 10 ]' tests the result is Less Than 10 otherwise sleep for 1 second and repeat . Note: Clever as this script is, inotify is smarter.

fix broken permissions

pushd rotates the stack so that the second directory comes at the top.
'pushd +1' is equivalent to 'pushd'. Can be 'pushd +3' or more generaly 'pushd +N'. Can also be 'pushd -N'. More description in 'man bash'.

google tts

recursively walk down no more than three levels and grab any file with an extension of mp3, mpg, mpeg, or avi

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.


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