學習unp網路程式設計，樹上的例子均存在#include "unp.h"，故需要對環境進行配置。

2. 解壓並將unpv13e 移動到相應的資料夾下

3. 編譯

>$ cd unpv13e 
>~unpv13e/$ ./configure

>~unpv13e/$ cd lib
>~unpv13e/lib/$ make

>~unpv13e/lib/$ cd ../libfree
>~unpv13e/libfree/$ make

如若出現以下問題:

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:60:9: error: argument ‘size’ doesn’t match prototype
  size_t size;
         ^
In file included from inet_ntop.c:27:0:
/usr/include/arpa/inet.h:64:20: error: prototype declaration
 extern const char *inet_ntop (int __af, const void *__restrict __cp,
                    ^
make: *** [inet_ntop.o] Error 1
 

則需要:

>~unpv13e/libfree/$ vim inet_ntop.c  //將第60行的 size_t size 改成 socklen_t size;
>~unpv13e/libfree/$ make // 改變完後重新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:152:23: warning: ‘best.len’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (best.base == -1 || cur.len > best.len)
                       ^
inet_ntop.c:123:28: 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，編譯成功生成靜態庫libunp.a

4. 將生成的libunp.a複製到/usr/lib下

>~unpv13e/libgai/$ cd ..
>~unpv13e/$ sudo cp libunp.a /usr/lib

5. 修改unpv13e/lib/unp.h並複製

>~unpv13e/$ vim lib/unp.h  // 將#include "../config.h" 改成 #include "config.h"
>~unpv13e/$  sudo cp lib/unp.h /usr/include
>~unpv13e/$ sudo cp config.h /usr/include

6. 編譯例子

>~unpv13e/$  cd intro
>~unpv13e/$  gcc daytimetcpcli.c -o cli -lunp