Commands by rymo (1)

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Change your swappiness Ratio under linux
This command allow you to set the swappiness var at 50 (default is 60). The value interval must be set between 0 and 100. If swappiness is high=Swap usage is high, if swappiness is low=Ram usage is high.

Replace spaces in a filename with hyphens
As long as you have perl based rename. You can check: =$ rename --help Unknown option: help Usage: rename [-v] [-n] [-f] perlexpr [filenames] That's the good one.

Transfer large files/directories with no overhead over the network
This invokes tar on the remote machine and pipes the resulting tarfile over the network using ssh and is saved on the local machine. This is useful for making a one-off backup of a directory tree with zero storage overhead on the source. Variations on this include using compression on the source by using 'tar cfvp' or compression at the destination via $ ssh user@host "cd dir; tar cfp - *" | gzip - > file.tar.gz

Get the current svn branch/tag (Good for PS1/PROMPT_COMMAND cases)
Get the svn info, grep for the "URL" of the repository, pull out the tag/branch/trunk, and then just show the helpful/meaningful bit.

How to speedup the Ethernet device
ethtool is used for querying settings of an ethernet device and changing them. In this example I setup 100 Mb/s full duplex on my Linux Box

Monitor memory fine-grained usage (e.g. firefox)
Sometimes top/htop don't give the fine-grained detail on memory usage you might need. Sum up the exact memory types you want

sort a JSON blob
For situations where you keep JSON in a VCS and you want your diffs to be sane, such as within a Chef configuration repo.

Never rewrites a file while copying (or moving)
Allows you to preserve your files when using cp, mv, ln, install or patch. When the target file exists, it will generate a file named XXX.~N~ (N is an auto-incremental number) instead of deleting the target file.

Run a command that has been aliased without the alias
Most distributions alias cp to 'cp -i', which means when you attempt to copy into a directory that already contains the file, cp will prompt to overwrite. A great default to have, but when you mean to overwrite thousands of files, you don't want to sit there hitting [y] then [enter] thousands of times. Enter the backslash. It runs the command unaliased, so as in the example, cp will happily overwrite existing files much in the way mv works.

Show what PID is listening on port 80 on Linux

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