The shuf command for Linux allows a command-line user to select a given number of random words from a wordlist. [jason@localhost ~]$ shuf -n 8 /usr/share/dict/words amphivasal thoracically U. bluet Dabih thioamid taxiing convictism[jason@localhost ~]$ shuf -n 8 /usr/share/dict/words amphivasal thoracically U. bluet Dabih thioamid taxiing convictism This can be used to generate a word … Read more
This function will allow your computer to speak. function shellspeak() { mplayer "http://translate.google.com/translate_tts?tl=en&q=$(echo $@ | sed ‘s/\s/+/’)" > /dev/null 2>&1; }function shellspeak() { mplayer "http://translate.google.com/translate_tts?tl=en&q=$(echo $@ | sed ‘s/\s/+/’)" > /dev/null 2>&1; } A script that will change all files in a directory to lowercase filenames. function lowercase() # move filenames to lowercase. { for … Read more
The wall command is a perfect way to send a message to all logged on users on a Linux machine. This is used when you shutdown to alert all users that the system will be shutting down. The example below shows me sending the output of the ps command to all users. ubuntu@ip-172-31-20-234:~$ sudo ps … Read more
Navigating the Linux filesystem is very easy. The cd command is used to move to another directory. But there are other ways too. To navigate back to the last directory you were in, type cd -. This will take you back to where you were before. ubuntu /usr/share $ cd – /home/ubuntuubuntu /usr/share $ cd … Read more
The useradd command is used to add new users on your Linux system. But it can be used for other things too. You may display the defaults for new users. jason-H55-USB3% sudo useradd -D GROUP=100 HOME=/home INACTIVE=-1 EXPIRE= SHELL=/bin/sh SKEL=/etc/skel CREATE_MAIL_SPOOL=nojason-H55-USB3% sudo useradd -D GROUP=100 HOME=/home INACTIVE=-1 EXPIRE= SHELL=/bin/sh SKEL=/etc/skel CREATE_MAIL_SPOOL=no Use the -s parameter … Read more
This is a variant of the shellshock bug for bash that still works on a patched system. I am using Ubuntu 14.04 and this still works for me. env VAR1=’me() {echo "hello"}\ ‘ /bin/touch /home/$LOGNAME/my.textenv VAR1=’me() {echo "hello"}\ ‘ /bin/touch /home/$LOGNAME/my.text So you can still put arbitrary content after the function definition in a bash … Read more
Use this command to find all files in a directory that are larger than 1 megabyte. find . -maxdepth 1 -type f -size +1M -exec ls -Shal {} \+ | headfind . -maxdepth 1 -type f -size +1M -exec ls -Shal {} \+ | head Here is this command in practice. This is a very … Read more
I recently created a new user with the adduser command. homer@deusexmachina:~/Documents$ sudo adduser jimkirk Adding user `jimkirk’ … Adding new group `jimkirk’ (1002) … Adding new user `jimkirk’ (1002) with group `jimkirk’ … Creating home directory `/home/jimkirk’ … Copying files from `/etc/skel’ … Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully … Read more
This useful shell script will print information about your Ethernet or Wireless adapter. This is very useful for getting a lot of information at once. #!/bin/sh DEV="eno16777736" echo "Showing information for the active network interface: $DEV." echo -e "-*- \e[1mGet timestamping information for your Ethernet device.\e[0m -*-" echo ethtool -T $DEV … Read more
There are many useful Linux tips that make the life of a Linux user much easier. One is for the VI or VIM editor. To open a file at a specific line; use this command. homer@deusexmachina ~/Documents/yadex-1.7.901 $ vim src/x11.h +33homer@deusexmachina ~/Documents/yadex-1.7.901 $ vim src/x11.h +33 This will open the file x11.h at line 33. … Read more
The sftp command allows a user to retrieve files on a remote machine and save them on their computer. Use this command to access the files: sftp -P 443 [email protected]:/home/homer/Downloads/*.pdf I have my SSH server running on port 443, so I need to specify that port when using this command. I am using Cygwin on … Read more
This bash shell script is useful for creating a new user and setting a password for that user. This allows you to just type a username and password and everything else is done for you. Very useful for someone who is in a hurry. #!/bin/bash echo "Type a username for your new account: " … Read more
The touch command ordinarily does not allow the user to create files with a filename like –rf, but if you want to really annoy someone then you may use this command to create one. homer@debian:~$ touch — ‘–rf ‘homer@debian:~$ touch — ‘–rf ‘ And now you have a file named –rf. -rw-r–r– 1 homer homer … Read more
The bash shell allows the user to redirect output from one application to another or to a file. This is very useful when you are building a one liner script to perform a certain action. Here is a simple redirection. ls > ls.outls > ls.out This redirects the output of the ls command to a … Read more
Change the default Plymouth theme on Ubuntu Changing the default plymouth theme on Ubuntu 14.10 is not very difficult. Just type this at the shell prompt. This will set the new theme. root@homer-eME730:~# update-alternatives –install /lib/plymouth/themes/default.plymouth default.plymouth /lib/plymouth/themes/ubuntustudio-logo/ubuntustudio-logo.plymouth 100root@homer-eME730:~# update-alternatives –install /lib/plymouth/themes/default.plymouth default.plymouth /lib/plymouth/themes/ubuntustudio-logo/ubuntustudio-logo.plymouth 100 Now we need to save our changes. root@homer-eME730:~# update-alternatives –config … Read more
The boxes utility for Linux allows you to render an ascii text box around text. Below is an example. homer@homer-eME730 19:14:21 ~ $ echo `echo "This is a sentence printed to the terminal."` | boxes /***********************************************/ /* This is a sentence printed to the terminal. */ /***********************************************/homer@homer-eME730 19:14:21 ~ $ echo `echo "This is a … Read more
The mount command shows information about your mounted partitions on your machine. iMac305:~ admin$ mount /dev/disk0s2 on / (hfs, local, journaled) devfs on /dev (devfs, local, nobrowse) map -hosts on /net (autofs, nosuid, automounted, nobrowse) map auto_home on /home (autofs, automounted, nobrowse) map -fstab on /Network/Servers (autofs, automounted, nobrowse) /dev/disk0s3 on /Volumes/Scratch (hfs, local, journaled)iMac305:~ … Read more
Use this command to capture packets with the tcpdump command. This will output to STDOUT, but you may use redirection to divert it to a text file. [root@deusexmachina homer]# tcpdump -i wlp2s0[root@deusexmachina homer]# tcpdump -i wlp2s0 This is the output that you get when you are capturing packets. This is on my home network, so … Read more
This sed trick will filter out the unwanted characters and leave only the letters ‘A’. homer@deusexmachina ~ $ echo "###AAA" | sed ‘s/###//gi’ AAAhomer@deusexmachina ~ $ echo "###AAA" | sed ‘s/###//gi’ AAA This is how to re-bind the annoying CAPS-Lock key to Esc. This can give that key a new use. xmodmap -e ‘clear Lock’ … Read more
Find all files larger than 1 megabyte in a directory. find . -maxdepth 1 -type f -size +1M -printf "%f:%s\n" | sort -t":" -k2find . -maxdepth 1 -type f -size +1M -printf "%f:%s\n" | sort -t":" -k2 Search a file for a certain string. grep "hello" my.txtgrep "hello" my.txt Get the hostname from an IP … Read more