Hi, Halesh, Same result as above, I am wondering if system() should be used if we want to pass some arguments as well. Thanks & Best Regards, Johnny Xing ________________________________________ From: Halesh S [mailto:halesh.tux@xxxxxxxxx] Sent: 2008年10月15日 16:52 To: johnny_xing Cc: korfuri@xxxxxxxxx; linux-c-programming@xxxxxxxxxxxxxxx Subject: Re: How to call another separate program and passing some variables in C? Try program 2 as below, no need to use sprintf In program 2: int main(int argc, char *argv[]) { int input1; printf("buffer is %s\n", argv[0]); input1 =atoi(argv[0]); printf("input1 value is %d\n",input1); } Halesh Try program 2 as below, no need to use sprintf In program 2: int main(int argc, char *argv[]) { int input1; char buffer[10]; printf("buffer is %s\n", buffer); input1 =atoi(buffer); printf("input1 value is %d\n",input1); } - Halesh 2008/10/15 johnny_xing <johnny_xing@xxxxxxxxxxxx> 2008/10/15 johnny_xing <johnny_xing@xxxxxxxxxxxx> Hi, I tried as what Hlalesh said and it doesn't work. Here is what I have: In program 1: system("/usr/local/src/program2 1"); In program 2: int main(int argc, char *argv[]) { int input1; char buffer[10]; sprintf(buffer, argv[0]); printf("buffer is %s\n", buffer); input1 =atoi(buffer); printf("input1 value is %d\n",input1); } The output is: buffer is /usr/local/src/parallel/asterisk input1 value is 0 Anything wrong with it? Thanks & Best Regards, Johnny Xing ________________________________________ From: Halesh S [mailto:halesh.tux@xxxxxxxxx] Sent: 2008年10月15日 14:34 To: johnny_xing Cc: korfuri@xxxxxxxxx; linux-c-programming@xxxxxxxxxxxxxxx Subject: Re: How to call another separate program and passing some variables in C? 2008/10/15 johnny_xing <johnny_xing@xxxxxxxxxxxx> Hi, Uriel Yes I need to execute two separate programs although I know it would be much easier if I could put into one program. The reason is the first program invokes lots of other modules and program and it has been fixed and running that I don't know how to add in the second program. However, if I could invoke the second program using system() and pass some integers to the second program to generate the output I want, it will be good enough. Eg: system("/usr/local/src/program2"); The problem is I don't know how to pass some integers upon invoking it. Is it something like this if I want to pass an integer 1? system("/usr/local/src/program2" 1); Use system("/usr/local/src/program2 1"); the argument will stored as string in *argv[] in 2nd prog. Convert back to integer using sprintf / any of ur own method. Halesh Thanks & Best Regards, Johnny Xing -----Original Message----- From: linux-c-programming-owner@xxxxxxxxxxxxxxx [mailto:linux-c-programming-owner@xxxxxxxxxxxxxxx] On Behalf Of korfuri@xxxxxxxxx Sent: 2008年10月14日 19:12 To: johnny_xing Cc: linux-c-programming@xxxxxxxxxxxxxxx Subject: Re : How to call another separate program and passing some variables in C? 2008/10/14, johnny_xing <johnny_xing@xxxxxxxxxxxx>: > Hi, > > Forgive me if my question is so simple as I am a newbie to programming.. > > I have two C programming and I want to call second C file within my first C > program, upon calling, I need to pass some variables (like 1 or 0) to the > second program. > > Can anyone tell me how to do? I searched system() but it seems not be able > to do this. > > Thanks & Best Regards, > > Johnny > > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-c-programming" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Hi, You can use system() if you build the command-line (e.g. with sprintf()) to pass the arguments you want. Then you can access it in your 2nd program with argc/argv. An alternative is to use fork() and execve(). Please note that you have to convert each argument to a string so execve() can use it. Here again you can use sprintf() for this purpose. But are you sure you need two separate programs ? You can build 2 C files together into one binary. That makes passing variables much easier as it results to a normal function call. Hope this will help Regards, Uriel -- Uriel "Korfuri" Corfa Epitech student -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
