Commands using xargs

The grep switches eliminate the need for awk and sed. Modifying vim with -p will show all files in separate tabs, -o in separate vim windows. Just wish it didn't hose my terminal once I exit vim!!

This will drop you into vim to edit all files that contain your grep string.

xargs can be used in this manner to download multiple files at a time, and xargs will in this case run 10 processes at a time and initiate a new one when the number running falls below 10.

get diskusage of files (in this case logfiles in /var/log) modified during the last n days:

n -> last modified n*24 hours ago

Numeric arguments can be specified as

+n for greater than n,

-n for less than n,

n for exactly n.

=> so 7*24 hours (about 7 days) is -7

1. find file greater than 10 MB

2. direct it to xargs

3. xargs pass them as argument to ls

this command works with one gziped file per table, and restore 4 tables in parallel.

use the locate command to find files on the system and verify they exist (-e) then display each one in full details.

The `-q' arg forces tail to not output the name of the current file

This allows the output to be sorted from largest to smallest in human readable format.

This command will find the biggest files recursively under a certain directory, no matter if they are too many. If you try the regular commands ("find -type f -exec ls -laSr {} +" or "find -type f -print0 | xargs -0 ls -laSr") the sorting won't be correct because of command line arguments limit.

This command won't use command line arguments to sort the files and will display the sorted list correctly.

If you want certain files out of a directory hierarchy, this will copy just the listed files, but will create the directory hierarchy in the new location ($DIR/)

xargs -P N spawns up to N worker processes. -n 40 means each grep command gets up to 40 file names each on the command line.

I used this because I needed to sort the content of a bunch of gzipped log files. Replace sort with something else, or simply remove sort to just rezip everything

The example command deletes all aliases for network interface 'em0' assuming that the aliases have netmask of 255.255.255.255 and the master IP has some other netmask (such as 255.255.255.0). See here -> http://my.galagzee.com/2009/07/22/deleting-all-network-interface-aliases/ for more on the rationale of this command.

Retrieve top ip threats from http://isc.sans.org/sources.html and add them into iptables output chain.

Only tested on Linux Ubunty Hardy. Works when file names have spaces. The "-maxdepth 2" limits the find search to the current directory and the next one deeper in this example. This was faster on my system because find was searching every directory before the current directory without the -maxdepth option. Almost as fast as locate when used as above. Must use double quotes around pattern to handle spaces in file names. -print0 is used in combination with xargs -0. Those are zeros not "O"s. For xargs, -I is used to replace the following "{}" with the incoming file-list items from find. Echo just prints to the command line what is happening with mv. mv needs "{}" again so it knows what you are moving from. Then end with the move destination. Some other versions may only require one "{}" in the move command and not after the -I, however this is what worked for me on Ubuntu 8.04. Some like to use -type f in the find command to limit the type.

Useful for deleting old unused log files.

I'm working in a group project currently and annoyed at the lack of output by my teammates. Wanting hard metrics of how awesome I am and how awesome they aren't, I wrote this command up.

It will print a full repository listing of all files, remove the directories which confuse blame, run svn blame on each individual file, and tally the resulting line counts. It seems quite slow, depending on your repository location, because blame must hit the server for each individual file. You can remove the -R on the first part to print out the tallies for just the current directory.

This is better than doing a "for `find ...`; do ...; done", if any of the returned filenames have a space in them, it gets mangled. This should be able to handle any files.

Of course, this only works if you have rename installed on your system, so it's not a very portable command.

This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files.

Alternately, you can do this to follow a specific list of log files:

sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log}