Linux: Automount USB external drive with autofs

To avoid any confusion with the base name of your USB block device, make alias using udev manager:

Making udev device name alias

Edit the file /etc/default/autofs and enable BROWSE and LOGGING:

-BROWSE_MODE="no"
+BROWSE_MODE="yes"

-#LOGGING="none"
+LOGGING="verbose"
Edit the file /etc/auto.master and comment all lines what are not commented.
Add to the end of /etc/auto.master this line:
/mnt /etc/auto.usbdrive --timeout=2

Create the file /etc/auto.usbdrive:
kingston -fstype=vfat,rw,uid=1000,gid=100,fmask=133,dmask=022,user :/dev/kingston1

Start autofs daemon:
$ (chmod +x /etc/rc.d/rc.autofs ; sh /etc/rc.d/rc.autofs start)

Plug-in the pendrive and see /var/log/messages:

Jul 27 13:29:46 keyra kernel: [17339.948942] sd 9:0:0:0: [sdb] Attached SCSI removable disk
Jul 27 13:30:00 keyra automount[5766]: attempting to mount entry /mnt/kingston
Jul 27 13:30:00 keyra automount[5766]: mount(generic): mounted /dev/kingston1 type vfat on /mnt/kingston
Jul 27 13:30:00 keyra automount[5766]: mounted /mnt/kingston
Jul 27 13:30:01 keyra automount[5766]: 1 remaining in /mnt
Unplug the device:

Jul 27 13:42:35 keyra automount[5766]: expiring path /mnt/kingston
Jul 27 13:42:35 keyra automount[5766]: unmounting dir = /mnt/kingston
Jul 27 13:42:35 keyra automount[5766]: expired /mnt/kingston
Jul 27 13:42:41 keyra kernel: [18115.356920] usb 2-2: USB disconnect, address 9

Shell: Using while loop to read file lines

while IFS= read -r LINE ; do echo "$(date) $LINE" ; done < 20110603-105216.log

Shell: Skip First Two Fields and Print the Rest of Line

Using awk:
$ echo 'This is a test blah foo bar etc' | awk '{print substr($0, index($0,$3))}'
a test blah foo bar etc

Using cut:
$ echo 'This is a test blah foo bar etc' | cut -d ' ' -f3-
a test blah foo bar etc

Shell: Read An Array Using C Style For Loop

$ CONCEITO=("ruim" "fraco" "mediano" "bom" "muito bom" "excelente") ; \

for((i=1;i<11;i++)) ; do echo "#$i = ${CONCEITO[$(($RANDOM%6))]}" ; done



#1 = excelente

#2 = fraco

#3 = ruim

#4 = bom

#5 = ruim

#6 = excelente

#7 = mediano

#8 = mediano

#9 = excelente

#10 = muito bom





Obs: Array length: ${#CONCEITO[@]}

Postgresql: show tables, show databases, show columns

mysql: SHOW TABLES
postgresql: \d
or
postgresql: SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';

mysql: SHOW DATABASES
postgresql: \l
or
postgresql: SELECT datname FROM pg_database;

mysql: SHOW COLUMNS
postgresql: \d table
or
postgresql: SELECT column_name FROM information_schema.columns WHERE table_name ='table';

Shell: Retrieve empty directories

$ find -type d -empty

Linux: Dell Server / Desktop / Laptop Find Out Service Tag Command

Type the command as follows as root user:

# dmidecode | grep --color -i serial

or

# dmidecode -t 1

Referência: cyberciti.biz/faq/linux-find-dell-service-tag-command