C # binary file operations (Content Search and data truncation)

Private void button2_click (Object sender, eventargs e) {var list = new list <frame> (); byte [] Buf; byte [] bytstart = {0x70, 0x6d, 0x6a, 0x73, 0x7a, 0x6a, 0x66, 0x72, 0x6d}; byte [] bytend = {0x70, 0x66, 0x72, 0x61, 0x6d, 0x65, 0x65, 0x6e, 0x64}; using (var fs = new filestream (@ "D: \ Avi \ 6.lxf", filemode. open) {Buf = new byte [FS. length]; var Len = (INT) FS. length; FS. read (BUF, 0, Len);} var fstart = 0; var fend = 0; var offset = 0; do {fstart = indexof (BUF, bytstart, offset); fend = indexof (BUF, bytend, fstart); debug. print ("{0 }~ {1} ", fstart, fend); If (fstart =-1 | fend =-1) {offset = Buf. length;} else {var frame = new frame {start = fstart + bytstart. length, end = fend,}; frame. length = frame. end-frame. start; frame. data = new byte [frame. length];
// Content capture
Array. copy (BUF, frame. start, frame. data, 0, frame. length); list. add (FRAME); offset = fend; offset + = bytend. length ;}} while (offset <Buf. length );}

　　

Method for searching strings

/// <Summary> /// report the index of the first matching item of the specified system. byte [] in this instance. /// </Summary> /// <Param name = "srcbytes"> system. byte [] to be searched. </Param> /// <Param name = "searchbytes"> system. byte [] to be searched. </Param> // <returns> if this byte array is found, the index position of searchbytes is used. If this byte array is not found, the value is-1. If searchbytes is null or the length is 0, the returned value is-1. </Returns> internal int indexof (byte [] srcbytes, byte [] searchbytes, int offset = 0) {If (offset =-1) {return-1 ;} if (srcbytes = NULL) {return-1;} If (searchbytes = NULL) {return-1;} If (srcbytes. length = 0) {return-1;} If (searchbytes. length = 0) {return-1;} If (srcbytes. length <searchbytes. length) {return-1 ;}for (VAR I = offset; I <srcbytes. length-searchbytes. length; I ++) {If (srcbytes [I]! = Searchbytes [0]) continue; If (searchbytes. length = 1) {return I;} var flag = true; For (VAR j = 1; j <searchbytes. length; j ++) {If (srcbytes [I + J]! = Searchbytes [J]) {flag = false; break ;}}if (FLAG) {return I ;}} return-1 ;}

Real-world class

    public class Frame    {        public int Start { get; set; }        public int End { get; set; }        public int Length { get; set; }        public byte[] Data { get; set; }    }

 

C # binary file operations (Content Search and data truncation)