inline heredoc instead of file

Question

I have a command (php file) which takes, as an argument, the location of a file.

eg.

$ php ./ScriptName.php /my/file/location.txt

Sometimes I only need one or two words, so I don't really want to create the location.txt file just so I can reference it with the next command - I'd rather pipe it with the command somehow. For example, consider the contents of location.txt from the above example being just:

mywords

Is there a way I can rewrite that original commandline argument to just provide the contents of a "virtual" file?

Answer 1

You can use a variant of the /dev/fd/0 trick to pass a string to a script which expects a file name:

php ./ScriptName.php php://fd/0 <<<'mywords'

For example, script.php contains:

<?php
   $handle=fopen($argv[1],"r");
   echo "Read: ".fgets($handle);
   fclose($handle);
?>

Running:

php script.php php://fd/0 <<<'Some text'

outputs:

Read: Some text

Answer 2

If you have a shell that allows process substitution such as zsh, bash or ksh, you could do

php ScriptName.php <(echo mywords)

The shell will set up some method to run the echo command in a different shell, and make the output available either as a named fifo or more commonly via a pipe and a filename of the form /dev/fd/XX.