unix programming book

C language advanced programming guide for unix platform (Attachment download)-Linux general technology-Linux programming and kernel information, the following is a detailed reading. C language advanced programming guide on unix platforms This post posted by zhan1094 is t

C language Although the C language has serious defects in memory management, it still Wang Wang in some application fields. C is still a good choice for programs that require the highest efficiency, good real-time performance, or are tightly tied to the operating system kernel. c good portability also adds points to it. But now a lot of other language portability is getting better, and C's advantage in this area may be gradually lost. Many existing programs can produce very good C code, such a

Today, our first book, based on XCode6.1 's latest version of Swift Grammar, has a lovely name: "The old code says programming to the Swift River," and a beautiful cover:This book is not a pedigree, it's just a five-bit it old yard kid.One day in May, we have a few old yards to the software park at the door of the small noodle restaurant to eat, chat suddenly on

= open (file, o_rdonly); #ifndef DUP2 Close (0); int newfd = DUP (OLDFD), #else int newfd = dup2 (OLDFD, 0); #endifclose (OLDFD); Mans 2 DUP #include The system calls DUP to copy the file descriptor OLDFD. Instead, dup2 copies the oldfd file descriptor to NEWFD. Two file descriptors point to the same open file. Both calls return a new file descriptor, or 1 if an error occurs. C, Open-dup2-close Strategy (2) Redirect to file There are 3 basic concepts, and using them is a program un

disk based on the disk location indicated by the handle, without checking whether the file is deleted. DU/etc/| sort-Nr | the more command indicates to display the directory/etc/. when viewing the usage of the directory, the sort parameter-Nr indicates to reverse sort by numerical sorting, because we want to sort the directory size, we cannot use the output of the human-readable size. Otherwise, the directory size contains the words K and M, which may lead to incorrect sorting. 5. In man's case

sigaction function manual. Sa_sigaction: An Alternative signal processing function. If sa_flags sets sa_siginfo, this function is called; otherwise, sa_handler is called. Let's look at an example, #include In the above sigactiondemo. in the C program, we call the sigaction function to set the processing function of the signal sigalrm, and add the signal sigint to the sa_mask field of the Act parameter of the sigaction function, indicates the process blocking signal SIGINT during the

For UDP network programming of Unix domain sockets, the server side is as follows: #include Client Program: #include UDP network programming for Unix domain sockets

following :#include unit16_t htons (unit16_t host16bitvalue);unit32_t htons (unit32_t host32bitvalue);/* Returns the value of the network byte order */unit16_t Ntohs (unit16_t net16bitvalue);unit32_t Ntohs (unit32_t net32bitvalue); /* Returns the host byte order value */s should be treated as a 16-bit value (for example, TCP or Udpport). Consider L as a 32-bit value (e.g. IPV4 address);In addition to the byte order problem for each field in the protocol header, there is a byte order problem wit

After reading the third chapter of advanced programming in the Unix environment, I also typed the code myself. I also explained some IO functions, including read/write/fseek/fcntl; here is mainly a C function, which is easier to understand. The fcntl function is well explained. It can obtain and change the attributes of the opened file (read-only, write-only, etc. Note the difference between the function an

advanced Programming for UNIX Environments (third edition) code compilationThis address: Http://blog.csdn.net/caroline_wendyDate: 2014.10.21. Download code:http://www.apuebook.com/code3e.html2. Install dependent libraries:sudo apt-get install Libbsd-dev3. Go to the download folder make4. Copying header files and dynamic link librariessudo cp./include/apue.h/usr/include/sudo CP./lib/libapue.a/usr/local/l

terminal. The function GetSID returns the process group ID of a session leader process.function declaration: #include pid_t getsid (pid_t pid); ? ? ? ? Returns:session leader ' s process group ID if OK,-1 On Error If the PID is 0, the function GetSID returns the process group number of the session leader process where the calling process resides.??Resources:"Advanced programming in the

clktck = 0; if (clktck = = 0) /* Fetch clock ticks per second first time */if ((Clktck = sysconf (_SC_CLK_TCK)) 0)Err_sys ("sysconf error");printf ("real: %7.2f\n", Real/(double) clktck);printf ("User: %7.2f\n",(tmsend->tms_utime-tmsstart->tms_utime)/(double) clktck);printf ("SYS: %7.2f\n",(tmsend->tms_stime-tmsstart->tms_stime)/(double) clktck);printf ("Child User: %7.2f\n",(tmsend->tms_cutime-tmsstart->tms_cutime)/(double) clktck);printf ("Child sys: %7.2f\n",(tmsend->tms_cstime-tmsstar

Transfer from http://www.cnblogs.com/zhuwbox/p/4221934.htmlThe sixth chapter of the Select Knowledge Point UNP under Linux has been described very clearly, and here we simply say the role of select and give the client instance of select. We know that select is one of the simplest supports for IO multiplexing, and poll and Epoll are the upgraded versions of select. In the UNIX Network programming Fifth Chapt

System Call Failure Reason analysis In UNIX programming, we often use system calls to accomplish the desired function, while at the same time we need to pay large sections of code to detect, output errors, and other contingencies. The following are the possible causes of a system call failure: The system may be in a resource shortage or the program may use resources that exceed the limit set by the syste

lowercase or uppercase letters[^ character table]//Match any characters that are not in the character listCutCut-c1-a//Extract the results of each line from the first character to the last character in a fileCut-c1-5 A//extract the result of each line from the first character to the 5th character in a fileCut-d:-f1/etc/shadow//Shadow each line in the file as: The result of the first segment of the split is extracted, that is, the user nameCut-d:-f1,6/etc/passwd//Each line in the passwd file is

, and process B executes lseek to set the current offset of the file of process B to 1000 bytes (at the end of the current file ), then process B calls write to write 100 bytes (the file length changes to 1100 bytes ). Then, the kernel switches to process a to run. process a runs write and writes the data from its current file offset (1500 bytes) to the file, so it overwrites the data written by process B. In the original case of this problem, lseek positions and writes data in sequence, instead

$ gcc -o dupdemo dup_demo.clienhua34:demo$ ./dupdemofd offset(before dup): 0fddup offset(after dup): 10fd offset(after dup): 10 The running result of dupdemo shows that the current file offset is set for the file descriptor obtained by DUP, and the current offset of the original file descriptor is also affected. This is because the new file descriptor obtained by the DUP function shares the same file table item with the original file descriptor, as shown in kernel data structure 1. Figure 1: DU

S_ixgrp Group-execution S_irwxo Other reads, writes, and executions S_iroth Others-read S_iwoth Others-write S_ixoth Others-execution Instance: The following program opens the set group ID bit for file Foo and closes the group execution bit. The file bar is forcibly set to a specified access permission. #include Compile the program file, generate the chmoddemo file, and then run the file, Lien000034: Demo $ gcc-O chmoddemo. cli

call...Error #133: Unknown error 133Error #134: Unknown error 134lienhua34:demo$3. multi-thread Extension In a thread-supporting environment, multiple threads share the process address space. Each thread has its own local errno to prevent one thread from interfering with another thread. The strerror () function is not thread-safe. This function stores the string corresponding to errnum in a static buffer and returns the pointer to the buffer. When another thread calls strerror (), it will reset

operation returns, the file offset increases the number of bytes actually read. The actual number of bytes read may be smaller than that of nbytes. 3.6 write function # Include For normal files, the write operation starts from the current offset of the file. If o_append is specified when the file is opened, the file offset is set to the end of the file, the file offset will increase the number of written bytes. /* Copy the standard input to the standard output */# Include [emailprotected]:/p