unix system programming book

The book "Advanced Programming in UNIX environments" comes with many small and exquisite programs. When I read this book, rewrite the code in the book according to your own understanding (most of them are on the copybook) to deepen your understanding (it's too difficult to r

The book "Advanced Programming in UNIX environments" comes with many small and exquisite programs. When I read this book, rewrite the code in the book according to your own understanding (most of them are on the copybook) to deepen your understanding (it's too difficult to r

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

UNIX Network Programming-Volume One: Socket Networking APIThe book is intended for those who want to write their own programs that can use the API to communicate with each other as sockets.Directory:1. Introduction2. Transport layer: TCP, UDP, and SCTP3. Introduction to Socket Programming4. Basic TCP Socket Programming5. TCP client/Server program example6. I/O mu

The book "Advanced Programming in UNIX environments" comes with many small and exquisiteProgramWhen I read this bookCodeI have rewritten it according to my own understanding (most of it is on the copybook) and deepened my understanding (it is too difficult to read a book, haha ). This example is successfully tested on

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

Lien0000342014-10-051 Process Control trilogy Overview UNIX provides basic process control primitives such as fork, exec, exit, and wait. With these process control primitives, we can complete basic operations such as process creation, execution, and termination. Process control can be divided into trilogy, • Part 1: fork creates a new process. • Part 2: Execute the new program with exec. • Part III: exit and wait processing termination and waiting fo

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

processor has been occupied by it. Process No. 0 is always a system state, if the No. 0 process after the end of the time slice, calculate the priority number and set the tag, so that the previous user process to continue to execute, whether it is a "system-state to user-state conversion." If it is, then there is the timing of scheduling, the timing of this arrangement is effective. Although there is this

This article mainly introduces how to start Python3 programming on Unix-like systems, and explains the most basic and intuitive method of using the Print function for various outputs, if you need a python script, refer to the following example. py, regardless of which Unix platform, can be executed through the interpreter on the command line: $ python script.p

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

Lien0000342014-08-251. file descriptor For the kernel, all opened files are referenced through the file descriptor. The file descriptor is a non-negative integer. When an existing file is opened or a new file is created, the kernel returns a file descriptor to the process. When reading or writing a file, use the file descriptor returned by open or creat to identify the file and send it as a parameter to read or write. By convention, the UNIX

2016.11.72 Scripting and the ShellGood system administrators write scripts. Scripts standardize and automate the performance of administrative chores and free up admins ' time for more important and More interesting tasks. In a sense, scripts is also a kind of low-rent documentation in this they act as an authoritative outline of the steps NE Eded to complete a particular task.Good system administrators hav

hang-out operation simply adds a semaphore value of 1 (increasing the number of available resources) and wakes up waiting for the semaphore value to become any thread greater than 0. 4.2 System v Signal VolumeThe System v Semaphore adds another level of complexity.* * Count Semaphore set: one or more semaphores (constituting a set), each of which is a count semaphore. **

Multi-thread programming in Unix/Linux 1. ThreadA thread is usually called a lightweight process. Although this method is somewhat simplified, it is helpful to understand the concept of thread.Because threads and processes are relatively small, threads consume less CPU resources. Processes often need their own resources,However, resources can be shared between thread

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

make command.The following is the error message and solution when compiling the source code (assuming your working directory is the same as mine, it is/usr/local/apue.2e)Error 1:Myls. C: 1: 19: apue. h: no such file or directoryMyls. C: In function 'main ':Myls. C: 13: Error: 'null' undeclared (first use in this function)Myls. C: 13: Error: (each undeclared identifier is reported only onceMyls. C: 13: Error: for each function it appears in .)Solution:Copy apue. H to the default

uniform set of rules that are determined by the needs of the project and the organization, rather than simply using the familiar approach of the programmer. Once determined, these criteria can be used as indicators for evaluating source code (using manual or automated processes). cert Coding rules are widely adopted in the industry. At the Cisco annual SECCON meeting in October 2011, Cisco Systems announced the adoption of the CERT C Security coding standard as the benchmark

Today, I read # include "apue. H" in the "advanced programming for UNIX environments" book. It is a header file written by him. On www.apuebook.com, I can find allCode. Code package download link: http://www.apuebook.com/src.tar.gz 1. Download the code package 2. decompress the code package to the working directory and decompress it to/root/apue/and tar-xzvf

); Aboutprintf" "); $Show_time (utbufp->ut_time); - - #ifdef Showhost -printf"(%s)", utbufp->ut_host); A #endif +printf"\ n"); the //printf ("one done!\n"); - $ } the the voidShow_time (Longtimeval) the { the Char*CP; -CP = CTime (timeval); inprintf"%12.12s", CP +4 ); the } the About intUtmp_open (Char*filename) { theFd_utmp =open (filename, o_rdonly); the } the + structUtmp * Utmp_next (void){ - structUTMP *RECP; the if(Fd_utmp = =-1 ){Bayi returnNullut; the } t