编译时出错？

Question

我在编译代码时遇到这些错误.我在user/include下有所有标题

g++ -Ip_appmanager/inc -Icore/inc p_appmanager/src/appmanager_process.cpp -o p_appmanager/obj/appmanager -lpthread -lparser
p_appmanager/src/appmanager_process.cpp: In function ‘int main(int, char**)’:
p_appmanager/src/appmanager_process.cpp:33:21: error: ‘getpid’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:101:19: error: ‘fork’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:105:70: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:109:19: error: ‘getppid’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:124:19: error: ‘fork’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:128:61: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:132:19: error: ‘getppid’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:147:19: error: ‘fork’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:151:73: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:155:19: error: ‘getppid’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:170:19: error: ‘fork’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:175:70: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:179:19: error: ‘getppid’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp: In function ‘void* pingThread(void*)’:
p_appmanager/src/appmanager_process.cpp:302:11: error: ‘sleep’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp: In function ‘void* fifoThread(void*)’:
p_appmanager/src/appmanager_process.cpp:815:22: error: ‘fork’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:818:72: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:842:64: error: ‘execl’ was not declared in this scope
p_appmanager/src/appmanager_process.cpp:865:72: error: ‘execl’ was not declared in this scope
make: *** [all] Error 1

我的内核版本是"Linux amit-bhaira 3.8.0-26-generic#38-Ubuntu SMP Mon Jun 17 21:46:08 UTC 2013 i686 i686 i686 GNU/Linux".相同的代码在另一台Linux机器上运行.

请帮我解决这个问题.

谢谢.

Answer 1

加 #include <unistd.h>

它适用于其他平台,因为它们使用旧版本的gcc(<4.7)进行编译,该版本意外地在某些系统头文件中包含了unistd.h.

Answer 2

从fork(2)手册页:

SYNOPSIS
       #include <unistd.h>

从exec(3)手册页:

SYNOPSIS
       #include <unistd.h>

从getpid(2)手册页:

SYNOPSIS
       #include <sys/types.h>
       #include <unistd.h>

从sleep(3)手册页:

SYNOPSIS
       #include <unistd.h>