Commands by ruslan (10)

  • Checks for syntax errors in PHP files modified in current working copy of a Git repository. Show Sample Output


    1
    git status -s | grep -o ' \S*php$' | while read f; do php -l $f; done
    ruslan · 2013-12-14 11:47:54 0
  • The sample command searches for PHP files replacing tabs with spaces. -u NONE # don't use vimrc Instead of retab! one may pass retab! 4 for instance. Look at this http://susepaste.org/69028693 also


    -2
    find $DIR -name *.php -exec vim -u NONE -c 'set ft=php' -c 'set shiftwidth=4' -c 'set tabstop=4' -c 'set noexpandtab!' -c 'set noet' -c 'retab!' -c 'bufdo! "execute normal gg=G"' -c wq {} \;
    ruslan · 2011-04-08 11:42:45 0
  • M - current revision, N - older revision


    1
    svn diff -r M:N file.php | patch -p0
    ruslan · 2011-03-29 04:15:02 2
  • Creates HTML code from PHP source Show Sample Output


    1
    php -s source.php > source.html
    ruslan · 2011-03-10 15:11:35 0

  • 0
    wget http://cmyip.com -O - -o /dev/null | grep -Po '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'
    ruslan · 2011-02-28 16:46:14 0
  • Get external IP of the current machine via http://cmyip.com Show Sample Output


    -3
    wget http://cmyip.com -O - -o /dev/null | awk '/\<title/ {print $4}'
    ruslan · 2011-02-15 05:58:30 1
  • in Debian-based systems apt-get could be limited to the specified bandwidth in kilobytes using the apt configuration options(man 5 apt.conf, man apt-get). I'd quote man 5 apt.conf: "The used bandwidth can be limited with Acquire::http::Dl-Limit which accepts integer values in kilobyte. The default value is 0 which deactivates the limit and tries uses as much as possible of the bandwidth..." "HTTPS URIs. Cache-control, Timeout, AllowRedirect, Dl-Limit and proxy options are the same as for http..."


    2
    sudo apt-get -o Acquire::http::Dl-Limit=20 -o Acquire::https::Dl-Limit=20 upgrade -y
    ruslan · 2011-02-14 05:24:49 0
  • This form is used in patches, svn, git etc. And I've created an alias for it: alias diff='diff -Naur --strip-trailing-cr' The latter option is especially useful, when somebody in team works in Windows; could be also used in commands like svn diff --diff-cmd 'diff --strip-trailing-cr'... Show Sample Output


    4
    diff -Naur --strip-trailing-cr
    ruslan · 2011-02-10 14:32:42 0
  • If colordiff utility installed, it is sometimes handy to call this command. Of course, you should create an alias for it. E.g. svndiff.


    1
    svn diff --diff-cmd="colordiff"
    ruslan · 2011-02-10 14:27:55 1
  • The command copies a file from remote SSH host on port 8322 with bandwidth limit 100KB/sec; --progress shows a progress bar --partial turns partial download on; thus, you can resume the process if something goes wrong --bwlimit limits bandwidth by specified KB/sec --ipv4 selects IPv4 as preferred I find it useful to create the following alias: alias myscp='rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4' in ~/.bash_aliases, ~/.bash_profile, ~/.bash_login or ~/.bashrc where appropriate. Show Sample Output


    17
    rsync --progress --partial --rsh="ssh -p 8322" --bwlimit=100 --ipv4 user@domain.com:~/file.tgz .
    ruslan · 2011-02-10 14:25:22 2

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set a reminder for 5 days in the future
setup for reminder in 5 days, added the date in the future. To run a job at 4pm three days from now, you would do at 4pm + 3 days, to run a job at 10:00am on July 31, you would do at 10am Jul 31 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

See how many more processes are allowed, awesome!
There is a limit to how many processes you can run at the same time for each user, especially with web hosts. If the maximum # of processes for your user is 200, then the following sets OPTIMUM_P to 100. $ OPTIMUM_P=$(( (`ulimit -u` - `find /proc -maxdepth 1 \( -user $USER -o -group $GROUPNAME \) -type d|wc -l`) / 2 )) This is very useful in scripts because this is such a fast low-resource-intensive (compared to ps, who, lsof, etc) way to determine how many processes are currently running for whichever user. The number of currently running processes is subtracted from the high limit setup for the account (see limits.conf, pam, initscript). An easy to understand example- this searches the current directory for shell scripts, and runs up to 100 'file' commands at the same time, greatly speeding up the command. $ find . -type f | xargs -P $OPTIMUM_P -iFNAME file FNAME | sed -n '/shell script text/p' I am using it in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html especially for the xargs command. Xargs has a -P option that lets you specify how many processes to run at the same time. For instance if you have 1000 urls in a text file and wanted to download all of them fast with curl, you could download 100 at a time (check ps output on a separate [pt]ty for proof) like this: $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' I like to do things as fast as possible on my servers. I have several types of servers and hosting environments, some with very restrictive jail shells with 20processes limit, some with 200, some with 8000, so for the jailed shells my xargs -P10 would kill my shell or dump core. Using the above I can set the -P value dynamically, so xargs always works, like this. $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' If you were building a process-killer (very common for cheap hosting) this would also be handy. Note that if you are only allowed 20 or so processes, you should just use -P1 with xargs.

Efficient count files in directory (no recursion)
$ time perl -e 'if(opendir D,"."){@a=readdir D;print $#a - 1,"\n"}' 205413 real 0m0.497s user 0m0.220s sys 0m0.268s $ time { ls |wc -l; } 205413 real 0m3.776s user 0m3.340s sys 0m0.424s ********* ** EDIT: turns out this perl liner is mostly masturbation. this is slightly faster: $ find . -maxdepth 1 | wc -l sh-3.2$ time { find . -maxdepth 1|wc -l; } 205414 real 0m0.456s user 0m0.116s sys 0m0.328s ** EDIT: now a slightly faster perl version $ perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' sh-3.2$ time perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' 205414 real 0m0.415s user 0m0.176s sys 0m0.232s

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"

Every Nth line position # (AWK)
A better way to show the file lines 3n + 1

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

Multi-line grep
Using perl you can search for patterns spanning several lines, a thing that grep can't do. Append the list of files to above command or pipe a file through it, just as with regular grep. If you add the 's' modifier to the regex, the dot '.' also matches line endings, useful if you don't known how many lines you need are between parts of your pattern. Change '*' to '*?' to make it greedy, that is match only as few characters as possible. See also http://www.commandlinefu.com/commands/view/1764/display-a-block-of-text-with-awk to do a similar thing with awk. Edit: The undef has to be put in a begin-block, or a match in the first line would not be found.

Encrypted archive with openssl and tar
The lifehacker way: http://lifehacker.com/software/top/geek-to-live--encrypt-your-data-178005.php#Alternate%20Method:%20OpenSSL "That command will encrypt the unencrypted-data.tar file with the password you choose and output the result to encrypted-data.tar.des3. To unlock the encrypted file, use the following command:" $ openssl des3 -d -salt -in encrypted-data.tar.des3 -out unencrypted-data.tar

pretend to be busy in office to enjoy a cup of coffee
using seq inside a subshell instead of a bash sequence to create increments.

Propagate a directory to another and create symlink to content
Lndir create from source directory to destination directory a full symlink tree of all contents of source directory, really useful for propagate changes from a directory to another.


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