Dear All,
Might I suggest/request that "set +n" should undo the effect of
"set -n" ?
For example:
#!/bin/bash
echo one
set -n
echo two
set +n
echo three
would print:
one
three
Here's why I think it would be useful:
1. Bash doesn't have a block-comment mechanism, like /* ... */
and this would provide one.
2. The documentation for "help set" says that flags can be undone with
"+", thus the inverse of -n is +n.
(though in contradiction , it also says that subsequent commands (which
would include the "set" are ignored)
3. It would allow for a neat hack with polyglots. For example:
#!/bin/bash -n
<?php /*
set +n
echo "Hello, from Bash"
exec /usr/bin/php -ddisplay_errors=E_ALL $0 $@
*/
echo "Hello from PHP ".phpversion()."\n";
//continue in PHP till the end of the file.
?>
(there is actually a serious purpose to this, namely to create a php-cli
script that shows all errors, despite the settings in the system-wide
php-ini file)
Example 3 works if you remove the "-n" and "set +n" parts, though it
then emits an annoying complaint about "?php: No such file or directory"
Thank you for your consideration,
Best wishes,
Richard
