История изменений
Исправление vM, (текущая версия) :
Потому что
This grep has been enhanced in an upwards-compatible way to provide the exact functionality of the historical egrep and fgrep commands as well. It was the clear intention of the standard developers to consolidate the three greps into a single command.
В то же время,
The old egrep and fgrep commands are likely to be supported for many years to come as implementation extensions, allowing historical applications to operate unmodified.
PS
См. также
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/fgrep.html
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/egrep.html
Исходная версия vM, :
Потому что
This grep has been enhanced in an upwards-compatible way to provide the exact functionality of the historical egrep and fgrep commands as well. It was the clear intention of the standard developers to consolidate the three greps into a single command.
В то же время,
The old egrep and fgrep commands are likely to be supported for many years to come as implementation extensions, allowing historical applications to operate unmodified.