Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

Hide

News

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

Mount a temporary ram partition

Terminal - Mount a temporary ram partition
mount -t tmpfs tmpfs /mnt -o size=1024m
2009-02-06 00:33:08
User: ajrobinson
Functions: mount
173
Mount a temporary ram partition

Makes a partition in ram which is useful if you need a temporary working space as read/write access is fast.

Be aware that anything saved in this partition will be gone after your computer is turned off.

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
ram() { mt=/mnt/ram && grep "$mt" < /proc/mts > /dev/null; if [ $? -eq 0 ] ; then read -p"Enter to Remove Ram Partition ";sudo umount "$mt" && echo $mt 0; else sudo mt -t tmpfs tmpfs "$mt" -o size=$(( ${1:-1} * 1024 ))m && echo $mt '-' "${1:-1}"gb; fi; }
2013-12-13 05:22:02
User: snipertyler
Functions: echo grep mt read sudo umount
Tags: sudo ram tmpfs
3

Creates a temporary ram partition

To use:

ram 3

to make a 3gb partition (Defaults to 1gb)

mdmfs -s 256m md /mnt
eatmydata disk_thrashing_command
2012-03-04 00:51:12
User: alphapapa
0

If you use eatmydata, all fsyncs will be ignored, so things will go much faster. Maybe not quite as fast as a ramdisk, but if you have enough free memory, the fs cache should help a lot. Just remember to sync afterwards--and if your system crashes in the middle of the command... :)

Know a better way?

If you can do better, submit your command here.

What others think

many systems come with a shared-memory "Device" pre-mounted. My distro (fedora) is mounted at /dev/shm.

Pretty handy when you want to borrow some ram for disk like purposes.

Comment by tsaavik 304 weeks and 1 day ago

this is really great if you run gentoo and are going to compile something - if you mount a tmpfs at /var/tmp/portage, it'll emerge while storing temp files in ram instead of on the harddrive, leading to a faster emerge that doesn't bog down your harddrive. Take note though, not everything will compile if you don't have enough ram, esp. if it's something like gcc or gtk... about 700mb should be fine (i think)

this might be of interest too:

https://wiki.ubuntu.com/BootToRAM

Comment by jlin64 304 weeks and 1 day ago

No doubt this would torn out the ram while doing heavy-duty work provided if mounted under restricted places ;)

Comment by bassu 285 weeks and 6 days ago

I have a detailed (verbose) notes on tmpfs here: http://www.askapache.com/web-hosting/super-speed-secrets.html

Comment by AskApache 245 weeks ago

the truth is... hard disks suck. they're cheap, yes, but they're slow. and they fail. if you have lots of redundancy, then maybe you can overcome these deficiencies through scale. but what about the end user masses who don't use some elaborate redundancy setup?

i've been using mfs and tmpfs instead hard disk for quite some time for both "code" and "data". i only use hard disk for stuff i need to save. after using ram exclusively for a while you begin to see just how slow and unreliable hard disks really are, and you'll unlikely want to go back to using disks.

ram is the next best thing to the cpu's registers. there are quite few registers with the new cpus... it seems like overkill... b/c most of them are going unused. but they are there for speed. ram is ridiculously slow by comparison.

Comment by argv 225 weeks and 1 day ago

For OSX (tested on 10.7.3):

diskutil eraseVolume HFS+ RAMDisk `hdid -nomount ram://$((1024*2048))`

This will be mounted at /Volumes/RAMDisk/

Comment by lowbatteries 141 weeks ago

On FreeBSD systems you can use :

mdmfs -s 32m md /mnt

Comment by QNimbus 103 weeks and 6 days ago

I use this with mysql for the tmp folder. any file sorts are done in ram rather than on disk.

mount tmpfs /tmp/mysqltmp/ -t tmpfs -o size=15G
Comment by denni 52 weeks and 2 days ago

Your point of view

You must be signed in to comment.

Related sites and podcasts