script function for detect if a pendrive is inserted and what's is dev

simona70 · 2018-10-17 15:24:21

This is my work. Anyone can use it.

  sget-pendrive() {
    n_found=0
    for drive in /dev/sd? ; do
      if [[ -b $drive ]] ; then

        letter=${drive:7:1}

        udev=`udevadm info -q path -n $drive`
        udev=`udevadm info -a -p $udev `

        #search KERNEL=="sdL"
        search=`echo KERNEL==\"sd$letter\"`
        udev_info=`echo "$udev" | grep $search | tr -d ' ' `
        [[ $udev_info != "KERNEL==\"sd$letter\"" ]] && continue

        udev_info=`echo "$udev" | grep 'SUBSYSTEM=="block"' | tr -d ' ' `
        [[ $udev_info != "SUBSYSTEM==\"block\"" ]] && continue

        udev_info=`echo "$udev" | grep 'ATTR{events}=="media_change"' | tr -d ' ' `
        [[ $udev_info != "ATTR{events}==\"media_change\"" ]] && continue

        udev_info=`echo "$udev" | grep -E 'ATTR{size}=="[0-9]{1,}"' | tr -d ' ' `
        [[ $udev_info != *"ATTR{size}=="* ]] && continue
        value=` echo "$udev_info" | cut -d "\"" -f2 | cut -d "\"" -f1 `
        [[ $value -lt 1 ]] && continue

        echo -e "Pendrive \e[1;39;41m$drive\e[0m (size $(($value *512/1000/1000/1000 ))GBi) detected."
        #echo -e "Pendrive \e[1;39;41m/dev/sd$drive\e[0m (size $(($value *512/1024/1024/1024 ))Gbyte) detected."

        n_found=$(( $n_found + 1 ))
      fi
    done
    [[ $n_found -lt 1 ]] && echo "No pendrive found" || echo "$n_found pendrives total found."
  }

Last edited by simona70 (2018-10-17 19:52:25)

Trilby · 2018-10-17 17:15:09

Please edit your post to use code tags.

Rather than looping through every letter in the alphabet and check for the presence of a device node, why not just do the following:

for drive in /dev/sd?; do

simona70 · 2018-10-17 19:35:10

Trilby wrote:

Please edit your post to use code tags.
Rather than looping through every letter in the alphabet and check for the presence of a device node, why not just do the following:
for drive in /dev/sd?; do

Thanks :-)

Morganamilo · 2018-10-17 20:01:35

Until you get >26 drives attached and it gets assigned /dev/sdaa ;)

Last edited by Morganamilo (2018-10-17 20:03:52)

Slithery · 2018-10-17 21:04:04

I usually just eyeball the output of lsblk to see which drives I have attached, but this could be a handy alias for when I'm about to write an image - thanks

What about drives that don't appear as /dev/sd*? There are external SSD drives that appear as /dev/nvme* when attached via USB 3.1 Type-C if you have the appropriate chipset. Come to think about it /dev/mmc* would fall into this category as well.

Edit - How about walking through...

lsblk -dloNAME | tail -n +2

...instead?

Last edited by Slithery (2018-10-17 21:09:56)

Trilby · 2018-10-17 22:47:06

Why the tail?

lsblk -ndlo NAME

fukawi2 · 2018-10-17 23:05:57

Some minor suggestions for improvements.

        udev=`udevadm info -q path -n $drive`
        udev=`udevadm info -a -p $udev `

Do you mean to immediately overwrite the udev variable with the second line?

        search=`echo KERNEL==\"sd$letter\"`

Unnecessary use of echo. Just double-quote "KERNEL=\"sd$letter\"" instead.

Slithery · 2018-10-18 00:15:44

Trilby wrote:

Why the tail?
lsblk -ndlo NAME

Obviously because I missed the -n option when reading the lsblk man page.

I assumed there would be such an option but I just couldn't see it, I think I'm going to have to put off the inevitable and succumb to glasses

Trilby · 2018-10-18 04:59:40

Wouldn't this do the same thing? I can't test here as I don't have multiple devices (and no removable drives):

#!/bin/bash

sget-pendrive() {
   for drive in $(lsblk -ndlo NAME); do
      udevadm info -a -p "$(udevadm info -q path -n $drive)" | awk -F\" '
         /SUBSYSTEM="block"/ { match++; }
         /ATTR(events)=="media_change"/ { match++; }
         /ATTR(size)=="[0-9][0-9]*"/ { value=$2; if (value > 0) match++; }
         END { if (match > 2) printf "Pendrive \e[1;39;41m'$drive'\e[0m (size %0.1fGBi) detected.", value; }'
   done
}

I dropped the test for KERNEL==sd$letter as that's a given, and this version doesn't (currently) count the number of devices found. But otherwise this should do the same thing with *far* fewer subshells and processes.

Last edited by Trilby (2018-10-18 05:01:25)

simona70 · 2018-10-20 09:30:20

Slithery wrote:

I usually just eyeball the output of lsblk to see which drives I have attached, but this could be a handy alias for when I'm about to write an image - thanks
What about drives that don't appear as /dev/sd*? There are external SSD drives that appear as /dev/nvme* when attached via USB 3.1 Type-C if you have the appropriate chipset. Come to think about it /dev/mmc* would fall into this category as well.
Edit - How about walking through...
lsblk -dloNAME | tail -n +2
...instead?

oh yes... thanks :-)

simona70 · 2018-10-20 09:31:43

Thanks for hints :-) I have written it to have exact /dev/... to use before dd if= of= for write image. A faster way. This final code say also size.
Interesting the:

sget-pendrive() {
   for drive in $(lsblk -ndlo NAME); do
      udevadm info -a -p "$(udevadm info -q path -n $drive)" | awk -F\" '
         /SUBSYSTEM="block"/ { match++; }
         /ATTR(events)=="media_change"/ { match++; }
         /ATTR(size)=="[0-9][0-9]*"/ { value=$2; if (value > 0) match++; }
         END { if (match > 2) printf "Pendrive \e[1;39;41m'$drive'\e[0m (size %0.1fGBi) detected.", value; }'
   done
}

Anymore for now this is final for now.

  sget-pendrive() {
    n_found=0
    for drive in /dev/sd?? /dev/nvme* ; do
      if [[ -b $drive ]] ; then

        letter=${drive:7:1}

        udev=`udevadm info -q path -n $drive`
        udev=`udevadm info -a -p $udev `

        search=`echo KERNEL==\"sd$letter\"`
        udev_info=`echo "$udev" | grep $search | tr -d ' ' `
        [[ $udev_info != "KERNEL==\"sd$letter\"" ]] && continue #not correct device

        udev_info=`echo "$udev" | grep 'SUBSYSTEM=="block"' | tr -d ' ' `
        [[ $udev_info != "SUBSYSTEM==\"block\"" ]] && continue #not correct device

        udev_info=`echo "$udev" | grep 'ATTR{events}=="media_change"' | tr -d ' ' `
        [[ $udev_info != "ATTR{events}==\"media_change\"" ]] && continue #not correct device

        udev_info=`echo "$udev" | grep -E 'ATTR{size}=="[0-9]{1,}"' | tr -d ' ' `
        [[ $udev_info != *"ATTR{size}=="* ]] && continue #not correct device
        value=` echo "$udev_info" | cut -d "\"" -f2 | cut -d "\"" -f1 `
        [[ $value -lt 1 ]] && continue #not correct device

        echo -e "Pendrive \e[1;39;41m$drive\e[0m (size $(($value *512/1000/1000/1000 ))GBi) detected."

        n_found=$(( $n_found + 1 ))
      fi
    done
    [[ $n_found -lt 1 ]] && echo "No pendrive found" || echo "$n_found pendrives total found."
  }

Last edited by simona70 (2018-10-20 09:39:36)

simona70 · 2018-10-20 09:43:14

I did also this small scripts to mount images (virtualbox, kvm, ecc.)

  #future to add???: iso and crypto file partitions
  srun-mount-img() {
    if [[ $1 == "-h" || $1 == "--help" ]] ; then
      echo "Sintax: srun-mount-img [--help|-h] file-name[.ext|.format] [format] [partition mumber inside volume 1-n]"
      echo "Allowed formats: $allow_formats"
      echo "Dont' forget to use 'srun-umount-img file-name.ext' to undo when finished."
      return 0
    fi

    if [[ ! -d "$HOME/mount/image" ]] ; then
      echo "Please create $HOME/mount/image with command 'mkdir -p $HOME/mount/image'. Exit."
      return 1
    fi

    if [[ ! -r /bin/qemu-nbd ]] ; then
      echo "Missing qemu-nbd command! Exit"
      return 1
    fi

    image="$1"
    if [[ $image == "" ]] ; then
      echo "Image missing. Please insert it as first paramater. Exit."
      echo "Sintax: srun-mount-img [--help|-h] file-name[.txt|.format] [format] [partition mumber inside volume 1-n]"
      return 1
    else
      image="$1"
    fi

    if [ ! -f "$image" ]; then
      echo "File image $image not found!! Exit."
      return 1
    fi

    ext="${image##*.}"

    #add iso
    #sudo mount -o loop path/to/iso/file/YOUR_ISO_FILE.ISO /media/iso
    #add crypto

    allow_formats="raw gcow2 vdi blkdebug blklogwrites blkreplay blkverify bochs cloop copy-on-read dmg file ftp ftps gluster host_cdrom host_device http https iscsi iser luks nbd nfs null-aio null-co nvme parallels qcow qcow2 qed quorum raw rbd replication sheepdog ssh throttle vdi vhdx vmdk vpc vvfat"

    format=$2
    if [[ $format == "" ]] ; then
      if [[ $ext != "" ]] ; then
        format=$ext
      else
        echo "Format missing. Please insert it as second paramater. Exit."
        return 1
      fi
    fi

    if [[ ! $allow_formats =~ $format ]] ; then
      [[ $format == "iso" ]] && echo "ISO: future implementation." || echo "Format $format unknown. Sorry. Exit."
      return 1
    fi

    if [[ -d "$HOME/mount/image/$image" ]] ; then
      echo "Directory $HOME/mount/image/$image already exist!! Exit."
      return 1
    fi

    [[ $3 == [0-9]* ]] && n_part=$3 || n_part=2

    mkdir -p "$HOME/mount/image/$image"
    if [ $? -ne 0 ]; then
      echo "Can't create directory $HOME/mount/image/$image! Exit."
      return 1
    fi

    sudo modprobe nbd max_part=63
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'modprobe nbd max_part=63'! Exit."
      return 1
    fi

    #-P, --partition=num           Only expose partition num use?
    sudo qemu-nbd -c /dev/nbd0 --format=$format "$image"
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'qemu-nbd -c /dev/nbd0 --format=$format \"$image\"'! Exit."
      return 1
    fi

    sudo mount /dev/nbd0p$n_part "$HOME/mount/image/$image"
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'mount /dev/nbd0p$n_part $HOME/mount/image/$image'! Exit."
      return 1
    fi

    cd "$HOME/mount/image/$image"
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'cd $HOME/mount/image/$image'! Exit."
      return 1
    fi

    echo "Dont' forget to use 'srun-umount-img file-name.ext' to undo when finished."
    return 0
  }

  srun-umount-img() {
    if [[ ! -r /bin/qemu-nbd ]] ; then
      echo "Missing qemu-nbd command! Exit"
      return 1
    fi

    image=$1
    if [[ $image == "" ]] ; then
      echo "Parameter image missing. Please insert it as first paramater. Exit."
      return 1
    fi
    if [[ ! -d "$HOME/mount/image/$image" ]] ; then
      echo "None to do. Directory $HOME/mount/image/$image do not exist!! Exit."
      return 1
    fi

    if [[ $PWD == "$HOME/mount/image/$image" ]] ; then
      cd "$HOME/mount/image"
      if [ $? -ne 0 ]; then
        echo "Can't execute command 'cd ..'! Exit."
        return 1
      fi
    fi

    sudo umount "$HOME/mount/image/$image"
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'umount $HOME/mount/image/$image'! Exit."
      return 1
    fi

    sudo qemu-nbd -d /dev/nbd0 >/dev/null
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'qemu-nbd -d /dev/nbd0'! Exit."
      return 1
    fi

    rmdir "$HOME/mount/image/$image"
    if [ $? -ne 0 ]; then
      echo "Can't execute command 'rmdir ~/mount/image/$image'! Exit."
      return 1
    fi

    return 0
  }

Last edited by simona70 (2018-10-20 09:51:23)

Arch Linux

#1 2018-10-17 15:24:21

script function for detect if a pendrive is inserted and what's is dev

#2 2018-10-17 17:15:09

Re: script function for detect if a pendrive is inserted and what's is dev

#3 2018-10-17 19:35:10

Re: script function for detect if a pendrive is inserted and what's is dev

#4 2018-10-17 20:01:35

Re: script function for detect if a pendrive is inserted and what's is dev

#5 2018-10-17 21:04:04

Re: script function for detect if a pendrive is inserted and what's is dev

#6 2018-10-17 22:47:06

Re: script function for detect if a pendrive is inserted and what's is dev

#7 2018-10-17 23:05:57

Re: script function for detect if a pendrive is inserted and what's is dev

#8 2018-10-18 00:15:44

Re: script function for detect if a pendrive is inserted and what's is dev

#9 2018-10-18 04:59:40

Re: script function for detect if a pendrive is inserted and what's is dev

#10 2018-10-20 09:30:20

Re: script function for detect if a pendrive is inserted and what's is dev

#11 2018-10-20 09:31:43

Re: script function for detect if a pendrive is inserted and what's is dev

#12 2018-10-20 09:43:14

Re: script function for detect if a pendrive is inserted and what's is dev

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