Does your script reference /bin/bash
or /bin/sh
in its hash bang line? The default system shell in Ubuntu is dash, not bash, so if you have #!/bin/sh
then your script will be using a different shell than you expect. Dash does not have the <<<
redirection operator.
Make sure the shebang line is:
#!/bin/bash
or
#!/usr/bin/env bash
And run the script with:
$ ./script.sh
Do not run it with an explicit sh
as that will ignore the shebang:
$ sh ./script.sh # Don't do this!