Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
menu search
person
Welcome To Ask or Share your Answers For Others

Categories

I would like to find the first occurence of an ANSI string in a binary file, using C++.

I know the string class has a handy find function, but I don't know how can I use it if the file is big, say 5-10 MB.

Do I need to copy the whole file into a string in memory first? If yes, how can I be sure that none of the binary characters get corrupted while copying?

Or is there a more efficient way to do it, without the need for copying it into a string?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
353 views
Welcome To Ask or Share your Answers For Others

1 Answer

Do I need to copy the whole file into a string in memory first?

No.

Or is there a more efficient way to do it, without the need for copying it into a string?

Of course; open the file with an std::ifstream (be sure to open in binary mode rather than text mode), create a pair of multi_pass iterators (from Boost.Spirit) around the stream, then search for the string with std::search.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
...