A personal list of LINUX commands useful to know

• halt                               halt system immediately
• shutdown                      regular shutdown
• reboot                           reboot immediately
• Ctrl-Alt-F1                   ASCII console
• Ctrl-Alt-F7                   back to X-windows environment
• ps -ef                            list all processes and process numbers
• ps -ef | grep <string>    look for processes containing <string>
• kill -9 <proc.no.>         kill process with <proc.no.>
• find / -name "<file>"     find <file> starting from the root directory /

• chmod ugo+w <file>    allow write access to <file> for user+group+others
• chmod 666 <file>         (alternate format of above command)
• chmod ugo+x <dir>      allow file creation and editing on directory <dir> for ugo
• chmod 777 <dir>          (alternate format of above command)

• ssh <host>                     secure shell login to host
• ssh <user>@<host>      ditto, changing user name
• ssh -X <host>                permit secopndary X-windows to be opened (SuSe, default for RedHat)
• scp <localfile> <user>@<remotehost>:<filename>    secure copy
• scp -r ...                         secure copy of directory
• sftp <user>@<host>      secure ftp with ftp-like script language

• .bashrc                               start-up file with shell settings
• PATH=$PATH:new          augment PATH with directory "new"
• export PATH                      make PATH available all over
• source .bashrc                     execute .bashrc after changes
• env                                      list all environment variables
• <VAR>=<name>                 set variable <VAR> to <name>
• alias                                     list all aliases
• alias <alias>="<string>"     define alias <alias> as <string>

• awk '/<string>/' <file>          search for <string> in <file> and display lines with <string> on stdout
• see awk primer for more