Subject: Re: bug#39999: BSD sed vs Gnu sed

From: Greg Troxel <[email-masked]>
Date: Wed, 29 Apr 2020 20:04:19 -0400

"W. Lincoln Harvey" via "Bug reports for GUILE, GNU's Ubiquitous
Extension Language" <[email-masked]> writes:

> backup file, BSD sed’s -i option requires a zero-length string as a
> mandatory argument, while Gnu sed’s -i option does not take any
> argument.

In cases like this, it is good to read the POSIX specs.

However, you will find that -i is not specified at all.

https://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html