how to count bytes

Linux-unix System Programming Manual Learning notes --michael Kerrisk 1. Linux proprietary programming Features: ⑴epoll, a mechanism for obtaining file I/O event notifications. ⑵inotify, a mechanism for monitoring file and directory

C language File read and write operation summary C Language File operation I. Reading and writing of standard documents 1. Open the file The open operation of the fopen () file means that the file specified by the user is allocated a filename in

1) String manipulation strcpy (P, p1) copy stringstrncpy (P, p1, N) copy the specified length stringStrcat (P, p1) Append stringStrncat (P, p1, N) append specified length stringStrlen (p) Take string lengthstrcmp (P, p1) comparison stringSTRCASECMP

Void * memcpy (void * dest, const void * src, size_t n );Copy n Bytes from the starting position of the memory address in the source src to the starting position of the memory address in the target dest.   Void * memmove (void * dest, const void *

1. Prototype declaration: Char *strcpy (char* dest, const char *SRC);Header files: #include and #include Function: Copy a string that starts from the SRC address and contains a null terminator to the address space starting with destDescription: The

Mknod command: used to create a special file prototype: # mknod [options] device file name {bcu} device No. Times device No. www.2cto.com option [-mmode] [-- modemode] [-- help] [-- version] option:-m, -- mode... Mknod command: used to create a

InputStream: Gets the byte input stream, Inputstream.read ("filename"),Reader: Reading a stream of charactersInputStreamReader: A bridge from bytes to characters. InputStreamReader (Inputstream.read ("filename"));Reader.read (InputStreamReader

Import struct Pack, unpack, pack_into, unpack_from   # Ref: http://blog.csdn.net/JGood/archive/2009/06/22/4290158.aspx Import struct # Pack-Unpack Print '= pack-Unpack =====' STR = struct. pack ("II", 20,400) Print 'str: ', STR Print

MAN 2 read NameRead-read from a file descriptor Synopsis# Include Ssize_t read (int fd, void * Buf, size_t count ); FD: the parameter is the file pointed to by the file descriptor. Buf: You want to read the specified memory. Size_t: How

RS-232 serial port, serial port by bit to send and receive bytes. Although it is slower than byte parallel communication, the serial port can use one line to send data while the other line to receive data. Typically, the serial port is used for

Mem series: Void * memset (void * DEST, int C, size_t count );Set the Count character before DEST to the character C. Return the value of DeST. Void * memmove (void * DEST, const void * SRC, size_t count ); Copy count byte characters from SRC to

Void * memset (void * DEST, int C, size_t count );Set count characters before DEST to C. Returns the value of DeST. Void * memmove (void * DEST, const void * SRC, size_t count ); Copy count byte characters from SRC to dest. If SRC and DEST

Linux file operation functions Original article address:Open () write () read () Close function in Linux Author:Yuxianxiaoxi 1. open () function Function Description: Used to open or create a file. When opening or creating a file, you can specify

1.2 file input and output functions The input and output of logical devices, such as keyboards, monitors, printers, and disk drives, can be completed through file management. The most commonly used disk files are used for programming. Therefore,

Function prototype: extern int memcmp (void * str1, void * str2, unsigned int N) Parameter description: str1 and str2 are the specified strings to compare the first n Bytes of the two strings.Database Name: # include Function: compare whether the

Detailed description of C ++ string functions [go] Reproduced from: http://zhanglong2004.spaces.live.com /? Owner = 1 Void * memset (void * DEST, int C, size_t count );Set count characters before DEST to C. Returns the value of DeST. Void * memmove (

1 memset Function Solution 1. Void * memset (void * s, int C, size_t N) Purpose: set the value of the first n Bytes of the memory space S to the value c.2. Example # includeVoid main () {char * s = "golden Global View ";Clrscr ();Memset (S, 'G', 6);

Close (close the file) Related functions Open, fcntl, shutdown, unlink, fclose Header file # Include Define functions Int close (int fd ); Function Description If the file is no longer needed after

Http://blog.chinaunix.net/u2/82646/showart_1359552.html Open (open a file) Related functions: read, write, fcntl, close, Link, stat, umask, unlink, and fopenHeader file # include # Include # Include Define the int open (const char * pathname, int

Original1. About Inputstream.read ()When reading data from a data stream, it is easy to use the Inputstream.read () method for diagrams.     This method is to read one byte at a time from the stream and is very inefficient. A better approach is to