Linux Snippets

Some assorted odds and ends in no particular order to save me re-Googling this kind of stuff... Itentify if you are 32-bit or 64-bit $ uname -a Convert png into jpg $ convert file.png file.jpg To open KDE Advanced Text Editor (kate) with root priviliges: $ kdesu kate ... and enter root password when prompted. Set group ownership of a file/folder: $ chgrp GroupName MyFolder Change smb passwords: Specifically, change a users smb password in the smbpasswd file $ smbpasswd -a foo Find IP address for Linux server on the LAN: $ /sbin/ifconfig Check versions of MySql, Perl, gcc etc: $ mysql -V $ perl -v $ gcc -v Identify GCC compiler version used in application % strings - yourapp | grep GCC Display CPU information: $ cat /proc/cpuinfo Find a file from root directory and all sub-directories: $ find / -name 'myfile.txt' Extract and install from tar.gz files: $ gunzip file.tar.gz $ tar -xvf file.tar cd to that directory, and: $ ./configure $ make $ sudo make install $ clean install Linux File Permissions Overview: drwxrwxrwx 1 user group 4096 2005-09-20 21:37 MyDir first column: file type: d/- directory/file columns 2-10: rwx permissions for user / group / other respectively followed by number of links, file/dir owner, group that dir/file belongs to, file size (bytes), date/time of last modification, file/dir name. Changing file permissions in numerical mode: $ chmod 755 MyDir This would change the MyDir's permissions to drwxr-xr-x. The owner would have full read, write, and execute permissions (7=4+2+1), the group would have read and execute permissions (5=4+0+1), and the others would have the read and execute permissions as well. Changing file permissions in symbolic mode: For example, to add write permission for the group use $ chmod g+w MyDir Checking if software installed For SuSE, Redhat, Fedora etc: $ rpm -qa | grep emacs For Ubuntu / Debian: $ dpkg -s emacs Finding the directory path of files and commands $ which emacs Update a boot sequence For SuSE, Redhat, Fedora etc: $ chkconfig --set SomeService on For Ubuntu / Debian: $ update-rc.d SomeService defaults Install a new package in Ubuntu Linux $ sudo apt-get install build-essential Search directory and it's subdirectories for a text string $ grep -r 'text' /dir To print the filenames only: grep -lr 'lhs' programs/ To seach and print files of a particular type $ grep -lr --include='*.java' 'text' dir/ Find changes made between main root branch and project branch in SVN $ svn log -v -r 1001768:HEAD http://svnserver.ubiquity.net/svn/product/branches/sb4.0/root/ > changes.txt Display current working directory path $ pwd Display all current processes $ ps aux | less Display available disk space $ df Zip files and directories For example, to compress all files of extension *.cpp or *.h into ExpressionParser.zip: $ zip ExpressionParser *.cpp *.h To recursively compress a directory and its sub-directories to a zip file: $ zip -r ZipFileName DirectoryName/ Cancel all print jobs $ lprm - Mount a windows partition $sudo sudo blkid This will list your devices (partition): /dev/sda1: LABEL="Local Disk" UUID="5AEC8638EC860F07" TYPE="ntfs" /dev/sda5: UUID="0f8b9c1d-9ce9-44e6-a95a-9c58299f1ca0" TYPE="ext4" /dev/sda6: UUID="0ec1636e-27bb-4dd0-a035-0a46760ba247" TYPE="swap" The /dev/sda1 / NTFS line is the one I am interested in. Then create a location to mount the partition: $sudo mkdir /mnt/win Then edit fstab using the text editor of choice eg leafpad: $sudo leafpad /etc/fstab Add the following line to fstab: #Evil mount point /dev/sda1 /mnt/win ntfs defaults 0 0 Finally, mount all partitions with: $sudo mount -a Check disk space $df

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