How can I write a here document to a file in Bash script?
Read the Advanced Bash-Scripting Guide Chapter 19. Here Documents.
Here's an example which will write the contents to a file at
cat << EOF > /tmp/yourfilehere
These contents will be written to the file.
This line is indented.
Note that the final 'EOF' (The
LimitString) should not have any whitespace in front of the word, because it means that the
LimitString will not be recognized.
In a shell script, you may want to use indentation to make the code readable, however this can have the undesirable effect of indenting the text within your here document. In this case, use
<<- (followed by a dash) to disable leading tabs (Note that to test this you will need to replace the leading whitespace with a tab character, since I cannot print actual tab characters here.)
if true ; then
cat <<- EOF > /tmp/yourfilehere
The leading tab is ignored.
If you don't want to interpret variables in the text, then use single quotes:
cat << 'EOF' > /tmp/yourfilehere
The variable $FOO will not be interpreted.
To pipe the heredoc through a command pipeline:
cat <<'EOF' | sed 's/a/b/'
... or to write the the heredoc to a file using
cat <<'EOF' | sed 's/a/b/' | sudo tee /etc/config_file.conf