echo
echo echo
eCho
eChO
eCHO
echo $
echo $ $
ECHO
echo rhobebou
echo stop barking
echo "bonjour"
echo bonjour
echo 'bonjour'
echo -n bonjour
echo -nn bonjour
echo -n -n -n bonjour
echo "-n" bonjour
echo -n"-n" bonjour
echo "-nnnn" bonjour
echo "-nnnn" -n bonjour
echo "-n -n -n"-n bonjour
echo "-n '-n'" bonjour
echo $USER
echo "$USER"
echo "'$USER'"
echo " '$USER' "
echo text"$USER"
echo text"'$USER'" ' $USER '
echo "text"   "$USER"    "$USER"
echo '              $USER          '
echo               text "$USER"            "$USER"text
echo ''''''''''$USER''''''''''
echo """"""""$USER""""""""
echo $USER'$USER'text oui oui     oui  oui $USER oui      $USER ''
echo $USER '' $USER $USER '' $USER '' $USER -n $USER
echo ' \' ' \'
echo '\" ' " \"\""
echo \\\" \\\" \\\" \\\"\\\"\\\" \\\'\\\'\\\'
echo "$USER""$USER""$USER"
echo text"$USER"test
echo '$USER' "$USER" "text \' text"
echo '$USER'
echo $USER " "
echo "$USER""Users/$USER/file""'$USER'"'$USER'
echo "$USER$USER$USER"
echo '$USER'"$USER"'$USER'
echo '"$USER"''$USER'"""$USER"
echo " $USER  "'$PWD'
echo " $USER  \$ "'$PWD'
echo $USER=4
echo $USER=thallard
echo $USER
echo $?
echo $PWD/file
echo "$PWD/file"
echo "text" "text$USER" ... "$USER"
echo $PWD
echo $PWD|cat -e
echo $PWD hallo | cat -e
echo '$PWD hallo | cat -e'
echo "$PWD hallo | cat -e"
wc < Makefile -l | cat -e > outfile | echo hello | rev > outfile2
< test.txt < Makefile<README.md wc -l|cat -e | rev
< Makefile cat > out | < README.md cat -e
< README.md cat -e | <Makefile cat
< in1 cat -e | < in2 cat
< in1 cat -e > out1 | < in2 cat
env | rev | head -5 | cat -e | rev
< in1 <in2 <in3 < Makefile rev | head -5 | cat -e | rev > out > out2 > out3 >> out4
echo ok"hello"ok1"mfg" == echo ok'hello'ok1'mfg'
echo okhellook1"mfg" == echo okhellook1'mfg'
echo "o""k       "hellook1 == echo 'o''k       'hellook1
echo '"***hello***"'
echo "'***hello***'"
echo ok"'hello'"ok1"hello1"ok2
echo "text"   "$USER"    "$USER"
echo """"""""$USER""""""""
echo "-n -n -n"-n bonjour
echo "'$USER'"
echo "$PWD         "a
echo "         $PWD"