File Management on Amit Agarwal Linux Blog

inotify -watch for file to change

Tue, 28 Jan 2014 00:41:45 +0000

Here is a simple command for you. It uses inotify tools. So first you need to install :

sudo yum install inotify-tools

and then you can try something like this:

while true; 
do 
inotifywait -r -e modify --exclude=".swp" . && make; 
done

Here, once the file changes, we are running make, but you can do anything you want.

Delete all but some directories

Fri, 16 Aug 2013 01:06:05 +0000

I think, like me, you would have faced a lot of situations, where you wanted to delete all the files or directories in a location, leaving only the required files/directories. So, I have a directory containing lots of files/directories and I want to delete most of them except some 5/10 of them, how to I do it.

I finally wrote a small script to do that. First save list of files that you do not want to delete in file called “listnames” and then execute the below script. This will give you the rm commands that you need to execute. If you want you can execute the rm command from the script, but to be able to review, I just have the commands echoed.

cksum – compare for multiple files.

Tue, 30 Apr 2013 01:15:30 +0000

If you have to compare cksum for couple of files, the you know how cumbersome it is. So, I wrote a simple script, wherein you can create a file called cksums in the current directory and copy paste the result of “**cksums ***” into this file, and then run this script. Cool 🙂

#!/bin/bash -
#===============================================================================
#
#          FILE: checkcksums.sh
#
#         USAGE: ./checkcksums.sh
#
#   DESCRIPTION: Compare cksums of multiple files.
#
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: Amit Agarwal (),
#  ORGANIZATION:
#       CREATED: 02/22/2013 09:12:17 PM IST
#      REVISION:  ---
#===============================================================================

file=cksums
while read line
do
    a=( $(echo $line) )
    if [[ -f ${a[2]} ]]
    then
        b=( $(cksum ${a[2]}) )
        if [[ $a == $b ]]
        then
            echo "Cksum for ${a[2]} = ${a[0]} matches"
        else
            echo "Failed ::Cksum for ${a[2]} = ${a[0]} matches"
        fi
    else
        echo "Failed :: file ${a[2]} does not exist"
    fi
done < $file

duff – find duplicate files.

Tue, 19 Mar 2013 11:44:38 +0000

duff – description:

Description : Duff is a command-line utility for quickly finding d

AURA Console (Photo credit: jameswatts.solfenix)

uplicates in a
given set of files

and now time to execute :

find . -type f -print0|duff -e0|xargs -0

This will print a list of duplicate files. If you directly want to delete them then you can use them in a rm command directly like ::

vim mappings for multiple files.

Mon, 06 Aug 2012 06:34:23 +0000

If you open multiple files in vim with command line option. Then the only way to move between the files is “:n” and “:N”. There is a easier way to do this. Just add mappings for this in vimrc. Here is what you can use.

map  :N
map  :n

And if you want to make sure that you move to the prev or next file after saving the file, then you modifyt the mapping like this:

rpmconf – Tool to handle rpmsave and rpmnew files

Mon, 18 Jun 2012 02:18:40 +0000

Install the utility:

sudo yum install rpmconf

Description:

Description : This tool search for .rpmnew, .rpmsave and .rpmorig files and ask you what to do

with them:

Keep current version, place back old version, watch the diff or merge.

And finally run the utility:

sudo rpmconf -a

and if there is a conflict or rpmsave or rpmnew file, then you will see something like this:

symlinks -delete all invalid soft links in Linux/Fedora

Tue, 12 Jun 2012 01:05:34 +0000

First of all, install symlinks if it is not installed :

sudo yum install symlinks

and here is the description:

Description : The symlinks utility performs maintenance on symbolic links.

Symlinks checks for symlink problems, including dangling symlinks

which point to nonexistent files. Symlinks can also automatically

convert absolute symlinks to relative symlinks.

Install the symlinks package if you need a program for maintaining

symlinks on your system.

and the help for the same:

Backup of files in the directory.

Thu, 01 Dec 2011 11:39:24 +0000

I was working on some scripts and the changes that I was making in the scripts was very dynamic, which I did want to keep backing up in the version control system. But for the peace of my mind, I wanted to keep a copy of the scripts, whenever it was in working state.

Since I had multiple files, so it would make more sense to have a script that could copy all the files in the current directory to “old” directory without over-writing the existing files. So, I wrote a script that would postfix the files with a number. With this approach, finally what I had was the following:

Compare files excluding certain lines.

Tue, 18 Oct 2011 11:12:15 +0000

Quick tip, you can use any expression for the sed commands in the (). With this trick you can redirect the stdout of 2 commands to the diff command. This might become very useful, if you want to compare 2 files, excluding the first line.

diff <(sed '1d' file) <(sed '1d' file2)

More interesting example is where the string ABC is converted to abc before comparing in the second file with the following command:

Get yourself some conkyrc files.

Wed, 05 Oct 2011 15:18:56 +0000

If you are looking for some nice conkyrc files, then you can head over to :

Ubuntu Forums

In this thread you can see some very nice conkyrc files with screenshots. You can browse through the thread and get the one that you like. But if you are like me and would like to download all of them to see the features and commands in each of them then you would need to copy each of these files and paste them separately. But if you have to do everything manually then there’s not much of being on Linux 🙂

some interesting alias

Tue, 27 Sep 2011 07:43:01 +0000

For this time, I will just give you a link to to bashrc file.

http://hayne.net/MacDev/Bash/aliases.bash

Head over there and see some very interesting aliase’s.

Bryan Quigley: Windows Cant Handle the Hardware (bryanquigley.com)
semantic grep (github.com)
Aliases and shortcuts (macstarter.com)

Empty a file

Sun, 26 Dec 2010 14:56:13 +0000

This one is for those who know the “touch” command. Hope all of us do not follow a command just because it is on one of the popular site without trying to understand the command and the output.

Take a screenshot of the window the user clicks on and name the file the same as the window title

Sun, 19 Dec 2010 14:45:06 +0000

Take a screenshot of the window the user clicks on and name the file the same as the window title

  <td>
    <div class="text codecolorer">
      &nbsp;sleep 4; xwd >foo.xwd; mv foo.xwd "$(dd skip=100 if=foo.xwd bs=1 count=256 2>/dev/null | egrep -ao '^[[:print:]]+' | tr / :).xwd"
    </div>
  </td>
</tr>

In general, this is actually not better than the “scrot -d4” command I’m listing it as an alternative to, so please don’t vote it down for that. I’m adding this command because xwd (X window dumper) comes with X11, so it is already installed on your machine, whereas scrot probably is not. I’ve found xwd handy on boxen that I don’t want to (or am not allowed to) install packages on.

New feature in Gnome/Nautilus

Sun, 05 Dec 2010 01:39:10 +0000

One of the things that I never realized that I am missing in Nautilus until they put the feature in was this. When a file is being copied and there is conflict, there should be option to rename the new file being copied. Also, if the file being copied is image then a small preview/thumbnail would be good.

Yesterday while copying some files, suddenly I noticed that this feature is there now. Pretty useful feature to have. Here’s the screen-shot.

function for copy files with progress bar (using pv – pipe viewer)

Thu, 11 Nov 2010 03:43:43 +0000

function for copy files with progress bar (using pv – pipe viewer)

  <td>
    <div class="text codecolorer">
      &nbsp;cp_p() { if [ `echo "$2" | grep ".*/$"` ]; then pv "$1" > "$2""$1"; else pv "$1" > "$2"/"$1"; fi; }
    </div>
  </td>
</tr>

dont have to type new file name (it copy file under same name) and dont have to use ‘/’ in the end of destination folder (but you can if u want, its idiot proof)

tee to a file descriptor

Fri, 13 Aug 2010 03:22:44 +0000

tee to a file descriptor

`1`	`$ tee >(cat – >&2)`

the tee command does fine with file names, but not so much with file descriptors, such as &2. This uses process redirection to tee to the specified descriptor.

In the sample output, it’s being used to tee to stderr, which is connected with the terminal, and to wc -l, which is also outputting to the terminal. The result is the output of bash –version followed by the linecount

bash script to change the vim colorscheme from the list of locally available schemes

Thu, 24 Jun 2010 20:51:35 +0000

: Image via Wikipedia

Today I was just wondering how good it would be to have a script to change the <a class="zem_slink freebase/en/vim" title="Vim (text editor)" rel="homepage" href="http://www.vim.org/">vim colorscheme from the <a class="zem_slink freebase/en/cmd_exe" title="Command Prompt" rel="wikipedia" href="http://en.wikipedia.org/wiki/Command_Prompt">command prompt. The plan for the script was simply to print the list of available schemes and then let the user select the actions from there on. So, here is the result:

Mirror or download a website with a tool much better than wget

Wed, 19 May 2010 16:38:39 +0000

If you want to mirror a <a class="zem_slink freebase/en/website" title="Website" rel="wikipedia" href="http://en.wikipedia.org/wiki/Website">website, the simplest tool I know if is <a class="zem_slink freebase/en/wget" title="Wget" rel="homepage" href="http://www.gnu.org/software/wget/">wget. Once you have used wget, you know the troubles associated with it. You also get added couple of files as search html files, which are useless and wastage of bandwidth for you as well as the <a class="zem_slink freebase/en/web_server" title="Web server" rel="wikipedia" href="http://en.wikipedia.org/wiki/Web_server">webserver.

lftp -e ”mirror -c”

Downloading all related videos from youtube with youtube-dl

Sun, 16 May 2010 15:53:16 +0000

How many time did you want to see all the videos (related) to the one you were watching on youtube but decided otherwise as the downloaded was not fast enough. Or has it happened to you that you wanted to <a class="zem_slink freebase/en/uploading_and_downloading" title="Uploading and downloading" rel="wikipedia" href="http://en.wikipedia.org/wiki/Uploading_and_downloading">download all the related videos, in either case you can use the youtube-dl utility I blogged about some times back. First you need to get all the <a class="zem_slink freebase/en/uniform_resource_locator" title="Uniform Resource Locator" rel="wikipedia" href="http://en.wikipedia.org/wiki/Uniform_Resource_Locator">URL’s in a <a class="zem_slink freebase/en/text_file" title="Text file" rel="wikipedia" href="http://en.wikipedia.org/wiki/Text_file">text file, and the simplest way to do this is :

top - looks better and is more useful with a rc file...

Fri, 07 May 2010 03:27:39 +0000

top is a very useful command to find out who is eating up the <a class="zem_slink freebase/en/central_processing_unit" title="Central processing unit" rel="wikipedia" href="http://en.wikipedia.org/wiki/Central_processing_unit">CPU or the memory. But sometimes the plain and simple look simply would be boring so how about some fun. Copy the below code to file : ~/.toprc

RCfile for ”top”
Id:a, Mode_altscr=1, Mode_irixps=0, Delay_time=5.000, Curwin=0
Def   fieldscur=mfcAbdEgHIursOpQTvyzWjKNLX
winflags=32184, sortindx=10, maxtasks=0
summclr=4, msgsclr=5, headclr=5, taskclr=4
Job   fieldscur=ABcefgjlrstuvyzMKNHIWOPQDX
winflags=62777, sortindx=0, maxtasks=0
summclr=6, msgsclr=6, headclr=7, taskclr=6
Mem   fieldscur=ANOPQRSTUVbcdefgjlmyzWHIKX
winflags=62777, sortindx=13, maxtasks=0
summclr=5, msgsclr=5, headclr=4, taskclr=5
Usr   fieldscur=ABDECGfhijlopqrstuvyzMKNWX
winflags=62777, sortindx=4, maxtasks=0
summclr=3, msgsclr=3, headclr=2, taskclr=3

bash script to change vim colorscheme based on the available themes

Sun, 11 Apr 2010 09:11:41 +0000

: Image via Wikipedia

Here’s one script that you may find useful. A little variation or wrapper for this script can make your life colorful 🙂

You can write a wrapper to this to take one of the inputs randomly and then use it in alias to start <a class="zem_slink freebase/en/vim" title="Vim (text editor)" rel="homepage" href="http://www.vim.org/">vim.

Linux find command – Find file and directories faster and easier

Tue, 16 Mar 2010 02:25:48 +0000

This command is very powerfull when used with combination of filters and pipes and RE.

I will give some example:

find . -type f –» List all files
find . -type f -exec rm {} <a class=“zem_slink” title=“Path (computing)” href=“http://en.wikipedia.org/wiki/Path_%28computing%29" rel=“wikipedia”>\; –» Delete all files
find . -type d -exec rm {} \; –» Will through some common errors 🙂
find . -name "name" –> find files containing name in the filename
find . -atime 12 –> Find files accessed 12 days ago

prepend to a file with sponge from moreutils

Tue, 16 Mar 2010 02:25:42 +0000

<a href="http://bashcurescancer.com/prepend-to-a-file-with-sponge-from-moreutils.html">A few weeks I wrote about a tool, which helps you easily prepend to a file. I submitted prepend to moreutils and Joey was kind enough to point out this could be done with `sponge’.? sponge reads standard input and when done, writes it to a file:
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Perl script to create csv files with a pattern – Generic script.

Tue, 19 Jan 2010 03:11:16 +0000

I was having a really bad day and needed a quick solution to create some csv files. And this I needed to do for multiple data kinds and patterns, so I created this small script to do the job for me…

#Number of rows required in the output.

$rows = 100;

#The config and the output file

open (CF_FILE, ”<Config.test”);
open (OUT_FILE, ”>test.csv”);

#—————————————————————————
# No need to change anything below this.
#—————————————————————————