RedHat/Fedora command sheets

RedHat Fedora

Packing, unpacking, and installing files: gzip compress: #gzip <filename.ext> gzip extract: #gunzip <filename.ext> gzip retrieve information about file: #gzip -l <filename.ext> tar archive: #tar cfv <archive name.ext> <file/folder to archive> tar extract: #tar xvf <filename.ext> tar retrieve information about file: #tar tvf <filename.tar> gzip and tar compress in one command: #tar cvzf <archive name.tar.gz> <file/folder to archive> gzip and tar extract in one command: #tar xvzf <filename.tar.gz> install rpm files: #rpm -ivh <rpm file name> install rpm package even if already installed: #rpm -ivh --replacepkgs <rpm file name> uninstall rpm packages: #rpm -e <rpm package name> After uninstalling an rpm package, you will find that it still has config files and other bits strewn about. The rm -rf and rm -f commands are VERY powerful and can easily render your linux installation unusable. Be very careful. A 'reasonably safe' way (provided you pay attention and are careful) to clean the files up is: 1) Do a find / -name "<filename>*" | more 2) Check the output and make SURE it only includes the files you want to remove. 3) Do a find / -name "<filename>*" | xargs rm -f tar basic functions and options: function: c To create a new archive x To extract files from an archive t To list the contents of an archive r To append files to the end of an archive u To update files that are newer than those in the archive d To compare files in the archive to those in the filesystem options: f <filename> To specify that the tar file to be read or written is named <filename> k To keep any existing files when extracting, i.e. don't delete the origional files v To make tar show the files it is archiving or restoring (don't use in shell scripts) z To specify that the data to be written to the tar file should be gzipped Miscellaneous commands: To download a web page(s): #wget -m -r -l5 Checking open network ports: #netstat -apn | more Show file attributes and permissions: #ll Show all files in a directory (including hidden .<name> files #ls -A Show information about mounted volumes: #df -h Turn off all power management: #xset -dpms Load StartX setup routine: #X86config Display log file starting at the end: #tail -f <file name> Samba commands: Add user/change password (user must have a unix account first): #smbpasswd -a <username> Apache commands: .htpasswd file creation for Apache Directory security use: To create a new .htpasswd file and add a user (will prompt for password): #htpasswd -c /etc/httpd/conf/.htpasswd <name> To create a new user in an existing .htpasswd file (will prompt for password): #htpasswd /etc/httpd/conf/.htpasswd <name> <Directory> security examples in httpd.conf (which use the .htpasswd file): <Directory "/var/www/html/<directory>"> AuthType Basic AuthName "Restricted Uploads" AuthUserFile /etc/httpd/conf/.htpasswd Require valid-user (means anyone in the .htpasswd file can access) </Directory> **and** <Directory "/var/www/html/<directory>"> AuthType Basic AuthName "Restricted file access" AuthUserFile /etc/httpd/conf/.htpasswd Require jjones (only jjones in the .htpasswd file has access) </Directory> RedHat/Fedora account creation: To create a new user account: #useradd <name> To add/change a password: #passwd <name> (will prompt for password twice) To add a user to a group: #usermod -G <groupname> <username> Set owner of a file/folder: #chown <user.group> <file/folder name> #chown -R >user.group> <file/folder name> for recursive, i.e. apply changes to subfolders Set permissions on a file/folder: #chmod 777 <file/folder name> for full rights (dangerous!) #chmod 775 <file/folder name> for full rights for user/group but no write/execute for 'other' #chmod 765 <file/folder name> for full user rights, no write for 'group', and no write/execute for 'other' Add -R for recursive, i.e. chmod -R 775 <file/folder name> to apply rights to subfolders File permissions take the form of: User Group Other -RWX RWX RWX The leading dash in the above table is for the type of data, d would be a directory and - indicates a file. File permissions can be set using bits, as referenced above: User Group Other read write execute read write execute read write execute 400 200 100 40 20 10 4 2 1 Another way to look at it would be to visualize -r--r--r-- and calculate it as: 400 40 4 = 444 ~examples~ File permissions of -rwxrwxr-x would be: 400+200+100 plus 40+20+10 plus 4+1 (no write for Other) which equals 775 File permissions of -rwxr-xr-x would be: 400+200+100 plus 40+10 plus 4+1 (no write for Group or Other) which equals 755 So, chmod -R 775 /var/www/html means /html and subfolders have -rwxrwxr-x or full rights except 'Other', which doesn't have write permissions. Making symbolic links: #ln -s &lt;location/filename> &lt;name of symbolic link> Example: ln -s /var/www/html/homesite homesite would create a link named homesite to /var/www/html/homesite which is a folder. Sending Root system messages and logs to an email address: Edit /etc/aliases Un-remark (remove # symbol) from 'root:' and add the email address of the recipient. Save file. At the command prompt, type newaliases to update the database. Enable daily yum updates: Pre-FC6 setup: # chkconfig yum on # service yum start Should see "Enabling nightly yum update: [OK]" FC6 and later setup (yum-cron is a seperate package): # yum install yum-cron # chkconfig yum-cron on # service yum-cron start Should see "Enabling nightly yum update: [OK]" Other yum features: List all available software: #yum list See if there are updated packages available: #yum check-update Update all installed packages that have a newer version available: #yum update Install specific package(s) (and its dependencies, if missing any): #yum install &lt;packagename> Search all known packages entries (descriptions etc) for &lt;word> #yum search &lt;word> Show basic information about a package #yum info &lt;packagename>