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$ nice -n19
for low CPU priority.
$ ionice -c3
for low I/O priority.
nocache can be useful in related scenarios, when we operate on very large files just a single time, e.g. a backup job. It advises the kernel that no caching is required for the involved files, so our current file cache is not erased, potentially decreasing performance on other, more typical file I/O, e.g. on a desktop.
http://askubuntu.com/questions/122857
https://github.com/Feh/nocache
http://packages.debian.org/search?keywords=nocache
http://packages.ubuntu.com/search?keywords=nocache
To undo caching of a single file in hindsight, you can do
$ cachedel
To check the cache status of a file, do
$ cachestats
I sometimes (due to mismanagement!) end up with files in a git repo which have had their modes changed, but not their content. This one-liner lets me revert the mode changes, while leaving changed-content files be, so I can commit just the actual changes made.
This command can be used to extract the title defined in HTML pages
This is a better version, as it does no command piping, uses for instead of while loops, which allows for a list of files in the current working directory to be natively processed. It also uses the -v/verbose option with mv to let you know what the command is doing.
While the command does exactly the same in a better way, I would modify the sed option to replace spaces with underscores instead, or dashes.
Please note that you'll receive errors with this command as it tries to rename files that don't even have spaces.
This is an alternative to: http://www.commandlinefu.com/commands/view/8761/renames-all-files-in-the-current-directory-such-that-the-new-file-contains-no-space-characters.
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"
Splits the file "my_file" every 500 lines. Will create files called xx01 xx02 and so on. You can change the prefix by using the -f option. Comes in handy for splitting logfiles for example. I am using it for feeding a logfile parser with smaller files instead of one big file (due to performance reasons)
Sorts a character string, using common shell commands.