linux_beginner.md

FS

• fhs

  / : Root directory

  /bin : Essential user command binaries (for use by all users)

  /sbin : Essential system binaries

  /dev : Devices and special files

  /dev/null
  
  /dev/zero
  

  /etc : Host-specific system configuration

  /lib, /lib64 and /lib32 : 64/32-bit libraries (architecture dependent)

  /proc : Kernel and process information virtual filesystem

  /usr/bin : Most user commands

  /usr/sbin : Non-essential standard system binaries

  /usr/include : Header files included by C programs

  /usr/lib : Libraries for programming and packages

  /usr/src : Source code

  /opt : Add-on application software packages

  /var/spool/cron : cron and at jobs

  /var/log : Log files and directories

  /root : Home directory for the root user

  /tmp : Temporary files

• pwd

• ls

• cat

• cd

• mkdir

• touch

• ln

• echo

• chmod

• chown

• rm

• cp

• mv

• file

• find

• df -h

• du

• tar

• gzip/gunzip

pipeline

• cmd1 | cmd2 |cmd3
• xargs

text processing

• grep/ack
• sed
• awk
• sort
• uniq
• head
• tail
• cut
• paste
• tr

$ echo 'abc' |tr 'a-z' 'A-Z'

• strings
• iconv

process

• ps
• kill
• top

memory

• vmstat
• free

IO

• iostat
• dstat
• ifconfig
• netstat

ssh

• ssh-keygen
• ssh ** port forward
• scp

sys

• uname -a
• ulimit -a
• cat /proc/cpuinfo
• cat /proc/meminfo

powerful tools

• lsof
• strace
• tcpdump
• nc/socat
• curl/wget
• rsync

misc

• alias/unalias \cmd
• export
• su
• type
• which

man

$ man man

refs

http://linuxcommand.org/

/lib64 and /lib32 are not so widely used, but /lib is.