copy /proc folder

2019-03-18 1 min read Bash Learning Linux

Other day, I was trying to copy the proc folder with following command:

tar cvzf /tmp/proc.tgz /proc

and I found out that all the files in tar were empty. Strange it may seem but lot of people are facing this as /proc is not a regular filesystem, so I wrote a quick script to copy the proc folder. Here is the script:

cd /
mkdir /tmp/proc
[[ -z $1 ]] && exit -1
find /proc/$1/ -not -name pagemap | while read F ; do
    D=/tmp/$F
    if [[ -d $F ]]
    then
        echo "$(ls -ld $F) => Directory"
        mkdir -p $D
    fi
    if [[ -L $F ]]
    then
        echo "$(ls -ld $F) => copied"
        cp -P $F /tmp/$F
        
    elif [[ -f $F ]]
    then
        echo "$(ls -ld $F) => Cat"
        cat $F > /tmp/$F
    else
        echo "Dont know $F"
    fi
done

cool sed/grep magic to convert output to csv format

2019-03-11 1 min read Bash Learning

I generallly keep doing this a lot, so thought will share with you. Lets assume we are capturing free ouput every min/hour/or whatever. The output looks like this:

Time: Mon Jan 21 23:59:10 AEDT 2019
——————-

total used free shared buff/cache available
Mem: 32014 8656 1735 1697 21621 21308
Swap: 51195 75 51120

then we can use some grep and sed to convert this to something like this:

Mon Jan 21 23:59:10 AEDT 2019,32014,8656,1735,1697,21621,21308
Continue reading

bash function for rpm whatprovides

2018-12-31 1 min read Bash Fedora Learning

Sometimes some simple one-liner function can save you a lot of time, like-

wps ()
{
    rpm -q --whatprovides $(which $1 )
}   # ----------  end of function wps  ----------

Directories with maximum number of files

2018-12-10 1 min read Bash

Lot of times, I want to find the directories with maximum number of files and so I wrote this quick function to do exactly the same

function count_lines ()
{
    oldIFS=$IFS
    count=0
    IFS=$'\n'
    dir=${1:-.}
    cd $dir
    find . -type d |while read line
    do
        echo -n "$(find $line -type f |wc -l) $line"
        echo 
        printf "Directories :: %8d\r" $count >&2
        ((count++))
    done|sort -n
    IFS=$oldIFS
}   # ----------  end of function count_lines  ----------

mv command with progress

2018-03-19 1 min read Bash

When moving large files/directories, I would like to see the progress.

Idea for this is to use rsync with progress and remove source files. But that option does not remove the empty directories left behind so find command to delete that.

So, here is function for that:

mv-progress () 
{ 
    rsync -ah --progress --remove-source-files "$1" "$2";
    find "$1" -empty -delete
}

Highest disk usage of directory in subdirectories

2018-03-12 1 min read Bash

I find myself doing this lot of times so thought will share this with you all. Basically, once I want to clear out the directory, I first want to find out the sub-directory using the maximum disk space so I wrote a function for that and here it is:

disk_usage_dirs () 
{ 
    find . -maxdepth 1 -type d -not -name '.' | while read line; do
        du -s "$line";
    done | sort -n | tail -${1:-5}
}

Some other posts you might find useful on this :

send mail using telnet from script

2017-12-25 1 min read Bash

If you have no other option but to use telnet with authentication to send mail 🙂

( echo "ehlo"
sleep 1
auth login
sleep 1
$(echo username |base64)
sleep 1
$(echo password |base64)
sleep 1
mail from: from-address
sleep 1
rcpt to: recepient
sleep 1
data
sleep 1
subject: test 
test mail
. 

exit ) |telnet server port

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