Badly placed ()'s error is found on my C code running on shell, how to solve the error?

Question

The below codes running on the shell has the error of Badly placed ()'s but I'm not able to figure out what's wrong with them.

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <time.h>

void current_time() {
    struct tm *current;
    time_t now;
    now = time(NULL);
    current = localtime(&now);
    printf("[%02i:%02i:%02i]  ", current->tm_hour, current->tm_min, current->tm_sec);
}

void gChild(int life,int input_data){
    time_t curtime;
    int pid = fork(); //fork() creating process and returning pid 
    if (pid == 0) {
        current_time();
        printf("  Grand-Child process started(process %d). The process will last for %d seconds.\n", getpid(), life);
        sleep(life);
        current_time();
        input_data++;
        printf("  Grand-Child process ended(process %d). iData is %d\n", getpid(), input_data);
        exit(0);
    } else if (pid == -1) {
        perror("Cannot start first-grandchild process.\n");
        exit(0);
    }
}

void Child1(int life,int input_data){
    time_t curtime;
    int pid = fork();
    if (pid == 0) {
        current_time();
        printf(" ~First Child process started(process %d). The process will last for %d seconds.\n", getpid(), life);
        sleep(life);        
        current_time();
        input_data++;
        printf(" ~First Child process ended(process %d). iData is %d\n", getpid(), input_data);
        exit(0);
    }
    else if (pid == -1) {
        perror("Cannot start first-child process.\n");
        exit(0);
    }
}

void Child2(int life, int gchildST, int ltgc, int input_data){
    time_t curtime;
    int pid = fork();
    if (pid == 0) 
    {
        current_time();
        printf(" ~Second Child process started(process %d). The process will last for %d seconds.\n", getpid(), life);      
        gChild(ltgc, input_data);       
        current_time();
        input_data++;
        printf(" Second Child process ended(process %d). iData is %d\n", getpid(), input_data);
        exit(0);
    }
    else if (pid == -1)
    {
        perror("Cannot start second-child process.\n");
        exit(0);
    }
}

void parent_code()
{
    while(1)
    {
        pid_t wait_rv = wait(NULL);
        if (wait_rv == -1)
            return;
    }
}
int main(int argCount, char *arg[])
{
    time_t curtime;
    int input_data;
    int ltc1, ltc2; //life times of the two child processes after which the two child processes will terminate
    int ltgc; //life time of the grandchild process
    int child1ST, child2ST; //starting times of the two child processes
    int gchildST; //starting times of the grandchild process

    if (argCount != 8) {
        printf("Invalid inputs.\n");
        return 0;
    }

    sscanf(arg[1], "%d", &input_data);  //%d for only accepting decimal values
    sscanf(arg[2], "%d", &child1ST);
    sscanf(arg[3], "%d", &child2ST);
    sscanf(arg[4], "%d", &ltc1);
    sscanf(arg[5], "%d", &ltc2);
    sscanf(arg[6], "%d", &gchildST);
    sscanf(arg[7], "%d", &ltgc);

    if (ltc1<=0 || ltc2<=0 || ltgc<=0)
    {
        printf("Invalid life time.\n");
        return 0;
    }

    if (child1ST<=0 || child2ST<=0 || gchildST <=0){
        printf("Invalid start-time.\n");
        return 0;
    }
    else if (ltc2 <= gchildST || ltc2 <= gchildST)
    {
        printf("Cannot start all grandchild processes during second process.\n");
        return 0;
    }

    current_time();
    printf("Parent process started(process %d).\n", getpid());

    if(child1ST<child2ST){
        sleep(child1ST);
        Child1(ltc1,input_data);
        sleep(child2ST-child1ST);
        Child2(ltc2, gchildST, ltgc, input_data);
    }
    else
    {
        sleep(child2ST);
        Child2(ltc2, gchildST, ltgc, input_data);
        sleep(child1ST-child2ST);
        Child1(ltc1,input_data);
    }
    parent_code();
    current_time();
    input_data++;
    printf("Parent process ended(process %d). iData is %d\n", getpid(), input_data);
    return 0;
}

I have been trying to find out the error by using the command of gcc -Wall to see what happen with it shows the following: In function 'gChild':

warning: implicit declaration of function 'fork'

warning: implicit declaration of function 'getpid'

warning: implicit declaration of function 'sleep'

warning: unused variable 'curtime'

In function 'Child1':

warning: unused variable 'curtume'

In function 'parent_code':

warning: implicit declaration of function 'wait'

In function 'main':

warning: unused variable 'curtime'

New error messages after adding libraries:

test.c: In function 'gChild':
test.c:23: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:27: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:19: warning: unused variable 'curtime'

test.c: In function 'Child1':
test.c:40: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:44: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:36: warning: unused variable 'curtime'
test.c: In function 'Child2':

test.c:59: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:63: warning: format '%d' expects type 'int', but argument 2 has 
type 'pid
_t'

test.c:54: warning: unused variable 'curtime'
test.c: In function 'parent_code':

test.c:77: warning: implicit declaration of function 'wait'
test.c: In function 'main':

test.c:121: warning: format '%d' expects type 'int', but argument 2 has 
type 'pi
d_t'

test.c:139: warning: format '%d' expects type 'int', but argument 2 has 
type 'pi
d_t'

test.c:84: warning: unused variable 'curtime'

You need to add std libraries working with processes.. for fork function is it #include and #include — Jakub Baski Gabčo, Mar 13 '14 at 06:55
Yes, this is one of the problem in my code. However, after adding those libraries, it shows another set of error messages in shell such as: warning format '%d' expects type 'int', but argument 2 has type 'pid_t' — Network study, Mar 13 '14 at 07:03
It means what it says. The `%d` in the format string indicates that the corresponding argument should be of type `int`, but you passed something of type `pid_t`. — pat, Mar 13 '14 at 07:10
or include `fcntl.h`, this way compiler will see that pid_t is an `int` — Dabo, Mar 13 '14 at 07:10
What do you mean "The below codes running on the shell"? Did you try to run this source code instead of to compile it? — Lee Duhem, Mar 13 '14 at 07:20
RE: leeduhem No, what I mean is I compile the source code on a Unix system using the shell script — Network study, Mar 13 '14 at 07:26
remember kids, if you cannot google for a simple compiler warning/error message, you're going to have a hard time.... — Karoly Horvath, Mar 13 '14 at 07:30
[This link](http://stackoverflow.com/questions/20533606/what-is-the-correct-printf-specifier-for-printing-pid-t) may be helpful. — Lee Duhem, Mar 13 '14 at 07:32
Finally I have removed all the error messages but the Unix system still tell me that there is Badly placed ()'s error. Can someone help me with this? — Network study, Mar 13 '14 at 07:58
This `void parent_code()` shall be `void parent_code(void)`, the same for `current_time()`. — alk, Mar 13 '14 at 08:01
RE alk: should I add void to all place with parent_code() and current_time() including calling of them? Or just add to the definition — Network study, Mar 13 '14 at 08:07
Still displaying the Badly placed ()'s error, I don't know why — Network study, Mar 13 '14 at 08:20
Networkstudy, if you say @alk instead of RE alk, he will be notified about that. — glglgl, Mar 13 '14 at 08:31
@Networkstudy How do you compile your source file in script? What is the **exactly** command? — Lee Duhem, Mar 13 '14 at 08:31
I simply type gcc test.c –o test and then type in the path of the code to compile it — Network study, Mar 13 '14 at 08:38

score 2 · Accepted Answer · edited May 23 '17 at 12:33

This program works just fine when I compile and run it.

The "badly placed ()" error is one of the shell, so I think you're not running the program correctly, but feeding the source code directly into the shell.

Also look at: C - Badly Placed ()'s?

I've done this:
- Put your code in stacko.c
- Execute gcc -g -Wall stacko.c
- Run program with ./a.out 10 1 2 10 10 3 7

Output:

[09:24:34]  Parent process started(process 11277).
[09:24:35]   ~First Child process started(process 11278). The process will last for 10 seconds.
[09:24:36]   ~Second Child process started(process 11279). The process will last for 10 seconds.
[09:24:36]   Second Child process ended(process 11279). iData is 11
[09:24:36]    Grand-Child process started(process 11280). The process will last for 7 seconds.
[09:24:43]    Grand-Child process ended(process 11280). iData is 11
[09:24:45]   ~First Child process ended(process 11278). iData is 11
[09:24:45]  Parent process ended(process 11277). iData is 11

Yes, I can compile it now. Thanks for your answer. But, can I ask do I need to type in ./a.out for all my projects on this kind of system? I just want to find out the real problem causing this. — Network study, Mar 13 '14 at 08:35
Well, of course, if every project is a separate application, you will need to do that. It all depends on what you're exactly trying to accomplish. You could however start by adding a "-o" flag with the name of the program, but "gcc --help" will tell you that. A good place to start is here: http://pages.cs.wisc.edu/~beechung/ref/gcc-intro.html Also the -g flag is for debugging symbols. If you don't need those, remove the flag — neeohw, Mar 14 '14 at 18:30

Badly placed ()'s error is found on my C code running on shell, how to solve the error?

1 Answers1