Getting errors while compiling?

8
votes

I am getting these errors when I am compiling my code. I have all the headers under user/include 

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

my kernel version is "Linux amit-bhaira 3.8.0-26-generic #38-Ubuntu SMP Mon Jun 17 21:46:08 UTC 2013 i686 i686 i686 GNU/Linux" . Same code is running on another linux machine.

please help me to fix this problem.

Thanks.

3
c++linuxubuntu
Is your code including <unistd.h>? – Oliver Matthews
Do you honestly believe we can magically solve your compiler errors without seeing the code? – user529758
@H2CO3: For those particular ones, yes. – Ignacio Vazquez-Abrams
If you have the proper man pages installed you can get most info with eg man getpid or another function you use. The manual will tell you which header to include and optional linking info. – hetepeperfan
@IgnacioVazquez-Abrams Wrong attitude. – user529758

3 Answers

54
votes

Add #include <unistd.h>

It works on other platforms because they are compiling with an old version of gcc (<4.7) which accidentally included unistd.h in some system headers.

6
votes

From the fork(2) man page:

SYNOPSIS
       #include <unistd.h>

From the exec(3) man page:

SYNOPSIS
       #include <unistd.h>

From the getpid(2) man page:

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

From the sleep(3) man page:

SYNOPSIS
       #include <unistd.h>
3
votes

You have forgotten #include <unistd.h> in your program.