Linux FAQ

Click on the links in the headings for more information.

Find files in a terminal

find / -type f -iname "*postgis-2.0.0*"

where:

• ./ indicates that you want to search in the current directory. This can be replaced with the directory you want to start your search from.
• f can be replaced with d if you’re searching for a directory instead of a file
• -iname can be replaced with -name if you want the search to be case sensitive
• * in the search term can be omitted if you don’t want the wildcards in the search. In this case, * indicates that any number of different characters could be present where the * is located in the string. See this link for more information on wildcards

The grep command can be used to simplify things further:

find . | grep -i "screen"

where -i indicates the search term is case insensitive. see this link for further details about the grep command.

Change file permissions

Change permissions :

chmod -R 755 your_directory

Value	Description
755	(rwxr-xr-x) The file’s owner may read, write, and execute the file. All others may read and execute the file. This setting is common for programs that are used by all users.

tar/untar or zip/unzip

Compress:

tar -zcvf archive_name.tar.gz directory_to_compress
tar -jcvf archive_name.tar.bz2 directory_to_compress
zip -r archive_name.zip directory_to_compress

Uncompress:

tar -zxvf archive_name.tar.gz
tar -jxvf archive_name.tar.bz2 -C /tmp/extract_here/
unzip archive_name.zip

Search for files in directory

find / -name 'program.c'

Find size of directory

du -sh folder
du -h -d1 folder # Only the top level directories.

Print all environmental variables

printenv

To show a list including the “shell variables”:

( set -o posix ; set ) | less

Download file from the internet

wget http://www.openss7.org/repos/tarballs/strx25-0.9.2.1.tar.bz2

Restart network manager (Ubuntu 16.04)

sudo systemctl restart NetworkManager
# or
sudo service network-manager restart

This is useful if you VPN disconnects and you get the following error when

trying to connect.

psam012@pc:~$ ssh psam012@bioeng10.bioeng.auckland.ac.nz
ssh: Could not resolve hostname bioeng10.bioeng.auckland.ac.nz: Temporary failure in name resolution

GUI utility to mount remote filesystems over SSH

Older versions of Ubuntu (<11.10)

By default the GVFS in GNOME supports SSH connections. Click on the nautilus icon (the folder with the house on it) it will launch the file manager.

Then go to File -> “Connect to server”:

Paste in the following:

Sever:	bioeng10.bioeng.auckland.ac.nz
Folder:	/hpc/upi
UserName:	upi

Click connect and put in your password (ask it to forget immediately for now)

This will mount the remote SSH server in a folder you can access from the file manager. If you need to access the mount in the command line it’s in .gvfs.

You can also mount it in Nautilus. Just hit CTRL+L and in the address bar type: ssh://server-ip/somepath/

Newer versions of Ubuntu (>11.10)

press Alt+F2 and type nautilus-connect-server as shown below.

Adding menu items in gnome ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^