Way to create multiline comments in Bash?

Question

I have recently started studying shell script and I\'d like to be able to comment out a set of lines in a shell script. I mean like it is in case of C/Java :

Answer 1

Here's how I do multiline comments in bash.

This mechanism has two advantages that I appreciate. One is that comments can be nested. The other is that blocks can be enabled by simply commenting out the initiating line.

#!/bin/bash
# : <<'####.block.A'
echo "foo {" 1>&2
fn data1
echo "foo }" 1>&2
: <<'####.block.B'
fn data2 || exit
exit 1
####.block.B
echo "can't happen" 1>&2
####.block.A

In the example above the "B" block is commented out, but the parts of the "A" block that are not the "B" block are not commented out.

Running that example will produce this output:

foo {
./example: line 5: fn: command not found
foo }
can't happen