how to use sed

[Amreena]

how to use sed

[Themer]

type "man sed" in the terminal and hit enter to get a manual.

By extension, almost all programs can be investigated for their use using this method.

[Amreena]

can I convert a bash script to an ash script easily

[Themer]

I suppose you could, yes, if you knew how to write/read both of them well enough. If you mean could you use sed to convert it for you, that's hard to say. If the syntax is very similar, then a find-and-replace method might do the trick, but if it's more complicated, then probably not.