C# prepend string to file

Software Development. Remote Development and Debugging Tools. Adding a new footer. Nested class structure question. How to use Nuget assembly as files with visual studio community. Undesired Name? Follow us! Get the Latest Bytes Updates. By using this site, you agree to our Privacy Policy and Terms of Use. Similar topics Python How to count lines in a text file? When there is not enough room for a prepend, move the data up by more than is strictly necessary.

This can bring performance back down to O n log n I think. A more refined approach is to make the buffer cyclic. In that way the spare space at both ends of the array becomes contiguous. You could build the string in reverse and then reverse the result. If I understand you correctly, the insert method looks like it'll do what you want. Just insert the string at offset 0. I haven't used it but Ropes For Java Sounds intriguing. The project name is a play on words, use a Rope instead of a String for serious work.

Gets around the performance penalty for prepending and other operations. Worth a look, if you're going to be doing a lot of this. A rope is a high performance replacement for Strings. The datastructure, described in detail in "Ropes: an Alternative to Strings", provides asymptotically better performance than both String and StringBuffer for common string modifications like prepend, append, delete, and insert.

Like Strings, ropes are immutable and therefore well-suited for use in multi-threaded programming. Try using Insert. Judging from the other comments, there's no standard quick way of doing this. Using StringBuilder's. I've included some other basic functionality such as append , subString and length etc. Both appends and prepends vary from about twice as fast to 3x slower than StringBuilder appends.

Like StringBuilder, the buffer in this class will automatically increase when the text overflows the old buffer size. ReadAllLines outPutFile. ToString ;. IO; using System. Write chunk, 0, chunk. Length ; writeStream. Seek initialOffsetWrite, SeekOrigin. Begin ; readStream. Seek initialOffsetRead, SeekOrigin.

Open file, FileMode. Seek 0, SeekOrigin. Length past the end of the file writeStream. Seek chunk. Length, SeekOrigin. Position - chunk. Seek -chunk. Current ; writeStream. Awaits a call to File. WriteAllLinesAsync which:. WriteAllTextAsync which:. There are additional conditions that may cause exceptions when working with the file system, it is best to program defensively. Skip to main content. This browser is no longer supported.