1 pwd
   2 cd /
   3 cd ~
   4 cd ..
   5 cd ~/public_html
   6 ls
   7 ls -l
   8 man ls
   9 whatis ls
  10 man whatis
  11 ls --help

   1 cd ~
   2 mkdir pr6_tmp
   3 ls
   4 cd pr6_tmp
   5 pwd
   6 cp ~/public_html/index.html .
   7 less index.html
   8 mkdir tmp_dir
   9 ls -l
  10 rmdir tmp_dir
  11 cd ..
  12 rmdir pr6_tmp
  13 man rm
  14 rm -r pr6_tmp
  15 mkdir tmp_pr6
  16 cp -r /P/y18/term2/block2/bash_files tmp_pr6
  17 cd tmp_pr6
  18 ls -l
  19 ls -l bash_files
  20 mv bash_files/Data.txt .
  21 ls -l
  22 ls -l bash_files
  23 mv Data.txt data.txt
  24 ls -l
  25 nano data.txt

   1 cd ~/tmp_pr6
   2 touch 1.txt
   3 man touch
   4 ls -l
   5 touch 2.txt 3.txt 10.txt 100.txt
   6 ls -l
   7 rm ?.txt
   8 rm *.txt
   9 touch 1 010.txt 213.tsv 333.exe 567.tmp
  10 rm *1*
  11 rm *[0-9]*
  12 cp ~/tmp_pr6/pdb/*pdb .

   1 cd ~/tmp_pr6
   2 echo "qwerty"
   3 echo "qwerty" > 1.tmp
   4 less 1.tmp
   5 echo "qwerty" > 1.tmp
   6 less 1.tmp
   7 echo "qwerty" >> 1.tmp
   8 less 1.tmp
   9 echo "123" > 2.tmp
  10 cat *.tmp
  11 man cat
  12 cat *.tmp | less
  13 man wc
  14 wc -l *.tmp
  15 cat *.tmp | wc -l
  16 cat *.tmp | wc -l | less
  17 cat *tmp > joint_files
  18 less joint_files
  19 wc -l < joint_files

   1 cd ~/tmp_pr6
   2 ls -la
   3 touch 1.tmp
   4 ls -la
   5 chmod a-rwx 1.tmp
   6 ls -la
   7 chmod o+x 1.tmp
   8 chmod g+w 1.tmp
   9 chmod a+rw 1.tmp
  10 chmod u+rx 1.tmp
  11 man chmod
  12 chmod 644 1.tmp
  13 mkdir tmpdir
  14 chmod 135 tmpdir
  15 cd tmpdir
  16 ls
  17 cd ..
  18 chmod 435 tmpdir
  19 cd tmpdir
  20 ls tmpdir
  21 touch tmpdir/1.tmp
  22 rmdir tmpdir