Commands by fsilveira (4)


  • 14
    rename -v 's/ /_/g' *
    fsilveira · 2009-08-28 17:28:57 1
  • Very helpful when you've got complex filenames and needs to change just some small parts of it. Renaming a file called "i-made-a-small-typo-right-here" to "i-made-a-big-typo-right-here": mv -vi i-made-a-{small,big}-typo-right-here You could also copy multiple files, edit, remove, process, etc. Show Sample Output


    1
    mv -vi file{,~}
    fsilveira · 2009-08-14 19:29:59 0
  • This lengthy cryptic line will print the latest top 10 commandlinefu.com posts without their summaries. To print also their respective summaries use the following (even bigger) command line: wget -qO - http://www.commandlinefu.com/feed/tenup | xmlstarlet sel -T -t -o '<doc>' -n -t -m rss/channel/item -o '<item>' -n -o '<title>' -v title -o '</title>' -n -o '<description>' -v description -o '</description>' -n -o '</item>' -n -t -o '</doc>' | xmlstarlet sel -T -t -m doc/item -v description/code -n -v title -n -n It is recommended to include this line into a shell script to be easily run, as I do myself. You could also use the following URLs to browse the top 3 commands: wget -qO - http://www.commandlinefu.com/feed/threeup | xmlstarlet ... .. or all others: wget -qO - http://feeds2.feedburner.com/Command-line-fu | xmlstarlet ... PS: You need to install "xmlstarlet" to run it. It is found in Debian APT repositories (apt-get install xmlstarlet) or under the http://xmlstar.sourceforge.net/ URL. Show Sample Output


    0
    wget -qO - http://www.commandlinefu.com/feed/tenup | xmlstarlet sel -T -t -o '&lt;x&gt;' -n -t -m rss/channel/item -o '&lt;y&gt;' -n -v description -o '&lt;/y&gt;' -n -t -o '&lt;/x&gt;' | xmlstarlet sel -T -t -m x/y -v code -n
    fsilveira · 2009-08-14 02:44:00 0
  • 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. Show Sample Output


    10
    find . -type f -printf '%20s %p\n' | sort -n | cut -b22- | tr '\n' '\000' | xargs -0 ls -laSr
    fsilveira · 2009-08-13 13:13:33 5

What's this?

commandlinefu.com 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.

Share Your Commands


Check These Out

execute a shell with netcat without -e
how to execute a shell on a server with a netcat binary which doesn't support -e option

Print just line 4 from a textfile
Prints the 4th line and then quits. (Credit goes to flatcap in comments: http://www.commandlinefu.com/commands/view/6031/print-just-line-4-from-a-textfile#comment.)

Substrings a variable
substrings a variable starting at position. If no offset given prints rest of the line

Remove the first character of each line in a file

scp file from hostb to hostc while logged into hosta
While at the command line of of hosta, scp a file from remote hostb to remote hostc. This saves the step of logging into hostb and then issuing the scp command to hostc.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Check if a command is available in your system
Usefull to detect if a commad that your script relies upon is properly installed in your box, you can use it as a function function is_program_installed() { type "$1" >/dev/null } Invoke it and check the execution code is_program_installed "dialog" if [ ! $? -eq 0 ]; then echo "dialog is not installed" exit 1 fi

generate 30 x 30 matrix
Replaces hexdump with the more succint xxd, and the sed was unnecessarily complex.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

strip non-constant number of directories from tar archive while decompressing
If you want to decompress the files from an archive to current directory by stripping all directory paths, use --transform option to strip path information. Unfortunately, --strip-components option is good if the target files have same and constant depth of folders. The idea was taken from http://www.unix.com/solaris/145941-how-extract-files-tar-file-without-creating-directories.html


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: