teffi的专栏

/* * ls1.c * purpose list contents of directory or directories * action if no args, use . else list files in args */#include <stdio.h>#include <sys/types.h>#include <dirent.h>void do_ls(char [])

初窥Unix系统编程本书通过以下3个步骤来学习。 1. 分析程序 首先分析现有的程序，了解它的功能及实现原理 2. 学习系统调用 看程序都用到哪些系统调用，以及每个系统调用的功能和使用方法。 3. 编程实现 利用学到的原理和系统调用，自己编程实现原来程序所实现的功能。以上3步可以通过下面3个问题来实现： * 它能做什么? * 它是如何实现的？ * 能不能自己编写一个？

/* * who1.c - a first version of the who program * open, read UTMP file, and show results */#include <stdio.h>#include <utmp.h>#include <fcntl.h>#include <unistd.h>#define SHOWHOST

/* hello_single.c - a single threaded hello world program */#include <stdio.h>#define NUM 5main(){ void print_msg(char *); print_msg("hello"); print_msg("world\n");}void print_msg(char *m)

/* * webserv.c - a minimal web server (version 0.2) * usage: ws portnumber * features: supports the GET command only * runs in the current directory * forks a new ch

/* * timeserv.c a socket - based time of day server */#include <stdio.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <netdb.h>#include <time

/* * prompting shell version 1 * Prompts for the command and its arguments. * Builds the argument vector for the call to execvp. * Uses execvp(), and never returns. */#include <stdio.h>#include <

/* * hello.c * purpose show the minimal calls needed to use curses * outline initialize, draw stuff, wait for input, quit */#include <stdio.h>#include <curses.h>main(){ initscr();

/* * spwd.c: a simplified version of pwd * * starts in current directory an recursively * climbs up to root of filesystem, prints top part * then prints current part * * uses readdir() to get in

/* twebserv.c - a threaded minimal web server (version 0.2) * usage : tws portnumber * features : supports the GET command only * runs in the current directory * creates a thread