cksum – compare for multiple files.

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

Related articles

• pycksum 0.4.0
• Checking if files are different using cmp
• Alternative to MD5 hash?

Using file partially for filenames

There are some commands that take file name and there are some case where you need to give file name. But there are some cases where you want to modify the file before passing it to the command. What do you do in these case’s?

I had a file containing huge amount of data and for some testing I wanted to pass only the first few lines of the file and not the complete file.  And since the file only accepted filename and would not take any input from the STDIN so only option was to create a file with the required data in a temporary file. So, I sat back to figure out some way to do it and finally found I can use this:

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

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)

Downloading all related videos from youtube with youtube-dl

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&#8217;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 :

Linux find command – Find file and directories faster and easier

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

Continue reading

prepend to a file with sponge from moreutils

<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&#8217;.? sponge reads standard input and when done, writes it to a file:
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