Gặp lỗi khi biên dịch?

Question

Tôi gặp phải các lỗi này khi tôi biên dịch mã của mình. Tôi có tất cả các tiêu đề dưới user/bao gồm

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 

phiên bản kernel của tôi là "Linux amit-bhaira 3.8.0-26-generiC# 38-Ubuntu SMP Mon 17 Tháng Sáu 21:46:08 UTC 2013 i686 i686 i686 GNU/Linux ". Cùng một mã đang chạy trên một máy linux khác.

hãy giúp tôi khắc phục vấn đề này.

Cảm ơn.

Answer 1

Thêm #include <unistd.h>

Nó hoạt động trên các nền tảng khác bởi vì chúng được biên soạn với một phiên bản cũ của gcc (< 4.7) mà vô tình bao gồm unistd.h trong một số tiêu đề hệ thống.

Answer 2

Bạn đã quên #include <unistd.h> trong chương trình của mình.

Answer 3

Từ trang fork(2) người đàn ông:

SYNOPSIS 
     #include <unistd.h> 

Từ trang exec(3) người đàn ông:

SYNOPSIS 
     #include <unistd.h> 

Từ trang getpid(2) người đàn ông:

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

Từ trang sleep(3) người đàn ông:

SYNOPSIS 
     #include <unistd.h>