How to use echo command to show '?

Question

for example I want to echo :

  "let vim know the last edit position
  au BufReadPost * if line("'\"") > 0|if line("'\"")
  \ <= line("$")|exe("norm '\"")|else|exe "norm $"|endif|endif

I tried but failed:

  echo '
  "let vim know the last edit position
  au BufReadPost * if line("\'\"") > 0|if line("\'\"")
  \ <= line("$")|exe("norm \'\"")|else|exe "norm $"|endif|endif
  '

How to show the correct format?

Thank you~

Answer 1

You can use here documents:

cat <<-EOF
  au BufReadPost * if line("'\"") > 0|if line("'\"")
  \ <= line("$")|exe("norm '\"")|else|exe "norm $"|endif|endif
EOF

Answer 2

If you want to use echo, all you need to do is to use single quotes

'string containing many strange characters $ " \ and so'

The only problem is posed by literal single quotes contained in the string.
In such a case:

1. close the string before the literal '
2. write and escaped single quote \'
3. reopen the string to continue with following characters

For example:

aaa'bbb  ==>  'aaa' + \' + 'bbb'  ==>  'aaa'\''bbb'

Obviously, if the literal single quote is at the start or end of the string, one of the closing or opening quote should not be used:

'aaa'bbb  ==>  \' + 'aaa' + \' + 'bbb'  ==>  \''aaa'\''bbb'

Your specific string can be output with the command

echo '"let vim know the last edit position
au BufReadPost * if line("'\''\"") > 0|if line("'\''\"")
\ <= line("$")|exe("norm '\''\"")|else|exe "norm $"|endif|endif'