学习unp网络编程，树上的例子均存在#include "unp.h"，故需要对环境进行配置。
1. 到资源页下载unpv13e
2. 解压并将unpv13e 移动到相应的文件夹下
3. 编译
>$ cd unpv13e
>~unpv13e/$ ./configure >~unpv13e/$ cd lib
>~unpv13e/lib/$ make >~unpv13e/lib/$ cd ../libfree
>~unpv13e/libfree/$ make
如若出现以下问题:
gcc -I../lib -g -O2 -D_REENTRANT -Wall -c -o inet_ntop.o inet_ntop.c
inet_ntop.c: In function ‘inet_ntop’:
inet_ntop.c::: error: argument ‘size’ doesn’t match prototype
size_t size;
^
In file included from inet_ntop.c:::
/usr/include/arpa/inet.h::: error: prototype declaration
extern const char *inet_ntop (int __af, const void *__restrict __cp,
^
make: *** [inet_ntop.o] Error
则需要:
>~unpv13e/libfree/$ vim inet_ntop.c //将第60行的 size_t size 改成 socklen_t size;
>~unpv13e/libfree/$ make // 改变完后重新make
>~unpv13e/libfree/$ cd ../libgai
>~unpv13e/libgai/$ make //以下只是warning, 乎略之
/usr/include/arpa/inet.h: In function ‘inet_ntop’:
inet_ntop.c::: warning: ‘best.len’ may be used uninitialized in this function [-Wmaybe-uninitialized]
if (best.base == - || cur.len > best.len)
^
inet_ntop.c::: note: ‘best.len’ was declared here
struct { int base, len; } best, cur;
^
gcc -I../lib -g -O2 -D_REENTRANT -Wall -c -o inet_pton.o inet_pton.c
ar rv ../libunp.a in_cksum.o inet_ntop.o inet_pton.o
a - in_cksum.o
a - inet_ntop.o
a - inet_pton.o
ranlib ../libunp.a
至此，编译成功生成静态库libunp.a
4. 将生成的libunp.a复制到/usr/lib下
>~unpv13e/libgai/$ cd ..
>~unpv13e/$ sudo cp libunp.a /usr/lib
5. 修改unpv13e/lib/unp.h并复制
>~unpv13e/$ vim lib/unp.h // 将#include "../config.h" 改成 #include "config.h"
>~unpv13e/$ sudo cp lib/unp.h /usr/include
>~unpv13e/$ sudo cp config.h /usr/include
6. 编译例子
>~unpv13e/$ cd intro
>~unpv13e/$ gcc daytimetcpcli.c -o cli -lunp
编译成功则大功告成。