apue.h 和unp.h

最近在学APUE和UNP，其中的apue.h 和unp.h需要自己动手，搜到一博文，亲自实验了一番，可以成功，先剪切到下面：

1.编译《APUE》
http://www.apuebook.com/src.tar.gz

在哪里编译都是一样，我们需要的是libapue.a 和apue.h文件。
我使用的目录是/home/dan/download/apue.2e/
修改Make.defines.linux文件中，
WKDIR=/home/dan/download/apue.2e
 
在我的机器上编译时，提示ARG_MAX未定义，可以这么修改。
在apue.2e/include/apue.h中添加一行：
#define ARG_MAX 4096
打开apue.2e/threadtl/getenv1.c 和apue.2e/threadctl/getenv3.c，添加一行：
#include "apue.h"

这样就可以编译通过了，复制apue.2e/include/apue.h到/usr/include下，
apue.2e/lib/libapue.a 到/usr/lib/和 /usr/lib64下。

2. 使用apue.h文件和libapue.a库。
假定/tmp下有一个文件：threadid.c，内容如下(apue线程章节的例子):
#include <apue.h>
#include <pthread.h>

pthread_t ntid;

void
printids(const char *s)
{
        pid_t           pid;
        pthread_t       tid;

        pid = getpid();
        tid = pthread_self();
        printf("%s pid %u tid %u (0x%x)\n", s, (unsigned int)pid,
          (unsigned int)tid, (unsigned int)tid);
}

void *
thr_fn(void *arg)
{
        printids("new thread: ");
        return((void *)0);
}

int
main(void)
{
        int             err;

        err = pthread_create(&ntid, NULL, thr_fn, NULL);
        if (err != 0)
                err_quit("can't create thread: %s\n", strerror(err));
        printids("main thread:");
        sleep(1);
        exit(0);
}

使用如下命令编译：
cc -o threadid threadid.c -lapue -lpthread
可以运行一下：
dan@dan-laptop:/tmp$ ./threadid
new thread:  pid 17490 tid 816015696 (0x30a36950)
main thread: pid 17490 tid 823949040 (0x311c76f0)

3. 编译《UNP》
这个稍微麻烦些。
http://www.unpbook.com/unpv13e.tar.gz
我们首先产生一个目录，以后自己的代码就敲在这个目录里。
mkdir /home/dan/study/unp

仍然是下载到/home/dan/download/，解压缩，进入目录
cd /home/dan/download/unpv13e/
README文件中说的很详细：
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
Execute the following from the src/ directory:

    ./configure    # try to figure out all implementation differences

    cd lib         # build the basic library that all programs need
    make           # use "gmake" everywhere on BSD/OS systems

    cd ../libfree  # continue building the basic library
    make

    cd ../libroute # only if your system supports 4.4BSD style routing sockets
    make           # only if your system supports 4.4BSD style routing sockets

    cd ../libxti   # only if your system supports XTI
    make           # only if your system supports XTI

    cd ../intro    # build and test a basic client program
    make daytimetcpcli
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
这里只编译lib下的文件，这样可以产生libunp.a，复制这个静态库到/usr/lib/和/usr/lib64/
如果提示：
unp.h:139: error: conflicting types for ‘socklen_t’
/usr/include/bits/socket.h:35: error: previous declaration of ‘socklen_t’ was here
需要注释掉当前目录中unp.h的第１３９行。
复制libunp.a到系统目录：
root@dan-laptop:/home/dan/download/unpv13e/lib# cp ../libunp.a /usr/lib
root@dan-laptop:/home/dan/download/unpv13e/lib# cp ../libunp.a /usr/lib64/

4.使用unp.h和libunp.a
如果直接复制unpv13e/lib/unp.h到/usr/include，那么在别的目录编译书上代码时，很可会得到类似下面的错误：
In file included from daytimetcpsrv1.c:1:
/usr/include/unp.h:227: error: redefinition of ‘struct sockaddr_storage’
In file included from daytimetcpsrv1.c:1:
/usr/include/unp.h:249:30: error: ../lib/addrinfo.h: No such file or directory
/usr/include/unp.h:263: error: redefinition of ‘struct timespec’
/usr/include/unp.h:363: error: conflicting types for ‘gai_strerror’
/usr/include/netdb.h:647: error: previous declaration of ‘gai_strerror’ was here
/usr/include/unp.h:367: error: conflicting types for ‘getnameinfo’
/usr/include/netdb.h:653: error: previous declaration of ‘getnameinfo’ was here
/usr/include/unp.h:371: error: conflicting types for ‘gethostname’
/usr/include/unistd.h:857: error: previous declaration of ‘gethostname’ was here
/usr/include/unp.h:387: error: conflicting types for ‘inet_ntop’
/usr/include/arpa/inet.h:65: error: previous declaration of ‘inet_ntop’ was here
/usr/include/unp.h:395: error: conflicting types for ‘pselect’
/usr/include/sys/select.h:121: error: previous declaration of ‘pselect’ was here
daytimetcpsrv1.c: In function ‘main’:
daytimetcpsrv1.c:9: error: ‘MAX_LINE’ undeclared (first use in this function)
daytimetcpsrv1.c:9: error: (Each undeclared identifier is reported only once
daytimetcpsrv1.c:9: error: for each function it appears in.)
dan@dan-laptop:~/study/unp/4$ rm -f /usr/include/unp.h
解决方法有点傻：
进入我们开始时建立的目录：
cd /home/dan/study/unp
复制config.h和unp.h到此目录：
dan@dan-laptop:~/study/unp$ cp /home/dan/download/unpv13e/config.h .
dan@dan-laptop:~/study/unp$ cp /home/dan/download/unpv13e/lib/unp.h .
修改unp.h，
#include "../config.h"改成 #include "config.h"
添加一行：
#define MAX_LINE 2048
练习书上代码时，在unp目录下建立相应的章节目录，文件中添加一行：
#include "../unp.h"
编译时链接unp库就可以了。

以第四章的daytimetcpsrv1.c为例：
dan@dan-laptop:~/study/unp/4$ pwd
/home/dan/study/unp/4
dan@dan-laptop:~/study/unp/4$ cat daytimetcpsrv1.c
#include "../unp.h"
#include <time.h>

int main(int argc, char **argv)
{
    int    listenfd, connfd;
    socklen_t    len;
    struct sockaddr_in    servaddr, cliaddr;
    char    buff[MAX_LINE];
    time_t    ticks;

    listenfd = Socket(AF_INET, SOCK_STREAM, 0);

    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(13);
   
    Bind(listenfd, (SA *)&servaddr, sizeof(servaddr));

    Listen(listenfd, LISTENQ);
   
    for (;;) {
        len = sizeof(cliaddr);
        connfd = Accept(listenfd, (SA *)&cliaddr, &len);
        printf("connection from %s, port %d\n",
            Inet_ntop(AF_INET, &cliaddr.sin_addr, buff, sizeof(buff)),
            ntohs(cliaddr.sin_port));

        ticks = time(NULL);
        snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));
        Write(connfd, buff, strlen(buff));

        Close(connfd);
    }
}
编译：
cc -o daytimetcpsrv1 daytimetcpsrv1.c -lunp
运行一下：
root@dan-laptop:/home/dan/study/unp/4# ./daytimetcpsrv1 &
[1] 22106
root@dan-laptop:/home/dan/study/unp/4#
root@dan-laptop:/home/dan/study/unp/4# ./daytimetcpcli
usage: a.out <IPaddress>
root@dan-laptop:/home/dan/study/unp/4# ./daytimetcpcli 127.0.0.1
connection from 127.0.0.1, port 42064
Fri Aug 21 23:03:56 2009
root@dan-laptop:/home/dan/study/unp/4# netstat -nt
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State     
tcp        0      0 127.0.0.1:13            127.0.0.1:42064         TIME_WAIT