Other tools

awk

• print the first and the last column, separated by tab, use field separator “,”

  awk -F ',' '{ print $1 "\t" $NF}'
  

find

• find and list world-writable files and directories in cwd and subdirectories

  find . -perm -a+w -type d,f -ls
  

• find suid/sgid executables in /usr and subdirectories

  find /usr -type f \( -perm -04000 -o -perm -02000 \)
  

screen

not so frequently used

• paste
• shuf