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Fdisk and grep command not working in udev trigger


 
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Top Forums Shell Programming and Scripting Fdisk and grep command not working in udev trigger
# 15  
Old 09-12-2018
Ah, bajeezus.. I somehow forgot this was about udev! Are there any errors in the system logs (dmesg, etc.)?
# 16  
Old 09-12-2018
Here what happened when issued run
Code:
udevadm trigger

manually.

Code:
cat weekly_backup.log

New usb device detected at
mount  /media/usb/test
mount: can't find /media/usb/test in /etc/fstab or /etc/mtab


and here the logs also when plugin my usb to the server, which is I get sameoutput in my log.

Code:
cat weekly_backup.log

New usb device detected at
mount  /media/usb/test
mount: can't find /media/usb/test in /etc/fstab or /etc/mtab

Im running in Centos 6.9

Thanks

------ Post updated at 08:20 PM ------

no error in dmesg sir
# 17  
Old 09-12-2018
OK, well apologies for the slight tangent I sent us off on, but again it comes back to this "DEVNAME" thing.

Before, or after, when you call fdisk..

Code:
DEVNAME=$(fdisk -l |grep FAT16 |awk '{print $1}')

can you add some debug to the log file?

Code:
fdisk -l |grep FAT16 |awk '{print $1}' 2>&1 >> $LOG_FILE

It seems that's not doing what you think it should be. Again, as previously suggested, you should fully qualify the commands (/usr/bin/grep, etc.) - shouldn't make any assumptions about the environment udev is using when it does stuff.

If you change all of the ">> $LOG_FILE" to "&>> $LOG_FILE", you'll also log all the errors, if there are any.
# 18  
Old 09-13-2018
Code:
cat  /usr/local/bin/test.sh

#!/bin/bash

LOG_FILE=/opt/weekly_backup.log

DEVNAME=$(/sbin/fdisk -l |/bin/grep FAT16 |awk '{print $1}') 2>&1 >> $LOG_FILE

#fdisk -l |grep FAT16 |awk '{print $1}' 2>&1 >> $LOG_FILE

sleep 2

echo "New usb device detected at $DEVNAME" &>> $LOG_FILE

echo "mount $DEVNAME /media/usb/test" &>> $LOG_FILE

sudo mount $DEVNAME /media/usb/test &>> $LOG_FILE

running this command
Code:
udevadm trigger

is working here the output of log

Code:
cat /opt/weekly_backup.log

New usb device detected at /dev/sdb1
mount /dev/sdb1 /media/usb/test

pluging the usb here the output:

Code:
New usb device detected at
mount  /media/usb/test
mount: can't find /media/usb/test in /etc/fstab or /etc/mtab

but if I put manually the
Code:
DEVNAME=/dev/sdb1

and plugin the usb is working
# 19  
Old 09-13-2018
I'll agree with Scott. It looks like something is not being set, or is not mounted to set. Maybe if you post the output of "mount" and "fdisk -l" we can see what's missing.
# 20  
Old 09-13-2018
Here's the output

Code:
fdisk -l

Disk /dev/sdb: 8019 MB, 8019509248 bytes
255 heads, 63 sectors/track, 974 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x78a9e380

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1         975     7830528    c  FAT16
Partition 1 has different physical/logical endings:
     phys=(973, 254, 63) logical=(974, 250, 44)

# 21  
Old 09-13-2018
Try "enhanced logging":

Code:
DEVNAME=$(fdisk -l |& tee -a $LOG_FILE | grep FAT16 |& tee -a $LOG_FILE | awk '{print $1}' |& tee -a $LOG_FILE)

and post the log file. Will that be the only disk having the FAT16 type?


Please also print the user that the script is executed under.

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