How to avoid heredoc expanding variables? [duplicate]

by

Just use 'EOF' to prevent the variable from expanding:

sudo /bin/su -c "cat << 'EOF' > /etc/init.d/my-script
#                       ^   ^

From man bash:

Here Documents

This type of redirection instructs the shell to read input from the
current source until a line containing only delimiter (with no
trailing blanks) is seen. All of the lines read up to that point are
then used as the standard input for a command.

The format of here-documents is:

      <<[-]word
              here-document
      delimiter

No parameter expansion, command substitution, arithmetic expansion,
or pathname expansion is performed on word. If any characters in word
are quoted, the delimiter is the result of quote removal on word, and
the lines in the here-document are not expanded. If word is
unquoted, all lines of the here-document are subjected to parameter
expansion, command substitution, and arithmetic expansion. In the
latter case, the character sequence \<newline> is ignored, and \
must be used to quote the characters \, $, and `.

More Related Contents:

  1. sed substitution with Bash variables
  2. here-document gives ‘unexpected end of file’ error
  3. Why does my Bash code fail when I run it with ‘sh’?
  4. How can I write a heredoc to a file in Bash script?
  5. Which characters need to be escaped when using Bash?
  6. How to execute a bash command stored as a string with quotes and asterisk [duplicate]
  7. How do I escape the wildcard/asterisk character in bash?
  8. How to assign a heredoc value to a variable in Bash?
  9. Using variables inside a bash heredoc
  10. Command substitution: backticks or dollar sign / paren enclosed? [duplicate]
  11. Variable containing multiple args with quotes in Bash
  12. How do I pass in the asterisk character ‘*’ in bash as arguments to my C program?
  13. Is there an easy way to pass a “raw” string to grep?
  14. Bash script to cd to directory with spaces in pathname
  15. How to suppress variable substitution in bash heredocs
  16. Command to escape a string in bash
  17. Passing a variable to a remote host in a bash script with ssh and EOF [duplicate]
  18. How do I properly escape data for a Makefile?
  19. Indenting heredocs with spaces
  20. How to match a single quote in sed
  21. How to echo a variable containing an unescaped dollar sign in bash
  22. escaping newlines in sed replacement string
  23. What’s the difference between “here string” and echo + pipe
  24. Bash: warning: here-document at line delimited by end-of-file (wanted `EOF’) [duplicate]
  25. Exactly how do backslashes work within backticks?
  26. How to get the primary IP address of the local machine on Linux and OS X? [closed]
  27. How to loop through dates using Bash?
  28. How do I read user input into a variable in Bash?
  29. Show Hexadecimal Numbers Of a File
  30. How to get the PID of a process in a pipeline

Leave a Comment