test.txt

cat > out < kjdfgkjsdh < $dlfkjkjsd | echo hello > out2 world | wc < $lkdjfkljsd < kdjsfkjsd
||
|<>
< f |<>
<< hello'' cat
<< hello cat
https://docs.google.com/spreadsheets/d/1fniV2dSRB5TaFGyX3O-iK0u61xR5jDdkFKYonKpilIc/edit#gid=0
export l="hello world" ; export $l ; export; export $l=k;
echo abcd = echo "abcd" = echo ab'cd'
echo $HO"ME" => ME
echo -n $ a  == echo -n $     a => $ a
echo -n "$     a" ==> $     a
cd $HOME/Documents ; unset HOME ; cd $HOME/Documents ==> no such a file ...
cat /dev/random | head -n 1 | cat -e
export "" ; unset ""
cat Makefile | grep pr | head -n 5 | cd test ; echo $?
cd ../../../../../.. ; pwd ; cd ~/Desktop/minishell/
export wa=at ; c$wa Makefile
sleep 5 | exit
export "l=p"=r ; export ==> (l="p=r")
> a echo Hello World! == echo Hello > a World!
exit 0 | exit 1
exit 1 | exit 0

minishell$ export l="<<"
minishell$ cat $l
cat: <<: No such file or directory
minishell$ $l
minishell: <<: command not found
minishell$ export l="'<< hello'"
minishell$ $l
minishell: '<<: command not found
minishell$ export l="k k"
minishell$ $k