Commands

Here are important commands that you should be aware of:

• cat : input from stdin or a file and output to stdout or a file
• cd : change directory
• date : show and set the system date and time
• df : find out how much space is free on your disks
  • df -h : find out how much space is free on your disks in a sensible format
• disown - removes a process from its parent process, allowing it to continue after the parent exits
• dig - query a name server for a server's IP address
• du -sch * : find out how much space is used on your disks
• echo : output a string to console (rather, to stdout)
  • echo mem > /sys/power/state : put the computer into standby-mode
• ethtool : is a network cable connected and which link does it have?
• fdisk : partition a hard disk
• file : find out the type of a file
• hwinfo : find out what harddisk, processor, graphics card and so on you have
  • hwinfo --block --short : find out what disks and partitions you have
  • hwinfo --cpu --short: find out what processors you have
• ldd : list dependencies of an executable file
• ls : list files
  • ls -ltr : list files, latest last
• lsof : list open files in the system
• mkdir : makes a directory
• netstat : show network connections
  • netstat -putan : show network connections in a sensible way
• ps : show running processes
  • ps -A : show all running processes
  • ps -ef : show all processes and their uptime
• route : manage the network routing table
• scp : copy over the network
• shred : wipe data off your computer
• sleep : waits for a given time
• ssh : call a program over the network on another computer
• strace : list all syscalls performed by a program
  • strace -e open : list all files that a program reads/writes to/from
• tar : pack and unpack file archives
  • tar -xvzf : unpack .tar.gz files
  • tar -xvjf : unpack .tar.bz2 files
  • tar -cvzf : pack to .tar.gz files
• top : show the top CPU/RAM consuming processes
• vmstat - how much I/O is your computer doing?
• which - where does a program lodge?
• xosview - gives you a nice overview about system load: CPU, disks, swap etc.
• zip - pack files so WinZip can extract them

See also

• pages that link to here
• software