a problem in using system()

[13sio]

hello,

i'm writing a interface by gtk+2.0 (a c based language) in linux. it's a window and have some buttons inside. when click a button, the program will call another software by system() command. if i do so, the interface window will halt. i wanna call another software and the window works normally.

thank you for your helping.

 

[dlkfjdlkfjdlfkd]

You'll need to create a spawn a separate process (see fork) or create another thread of execution (pthreads) within your program to handle the system call without freezing the interface.

 

[13sio]

hi,

thx dlkfjdlkfjdlfkd.

running the following code under RedHat 8.0,

----------------
#include <pthread.h>
#include <stdio.h>

void cb(void)
{
printf(&quot;%s&quot;, &quot;hi&quot;
}

int main (int argc, char *argv[])
{
pthread_t threads;
int rc;
rc = pthread_create(&threads, NULL, (void *)cb, NULL);
if (rc) {
printf(&quot;ERROR; return code from pthread_create() is %d\n&quot;, rc);
}
return 0;
}
----------------

there are statements as follows

/thread.o In function `main':
/thread.o(.text+0x3c): undefined reference to `pthread_create'
collect2: ld returned 1 exit status

 

[Salem]

> /thread.o(.text+0x3c): undefined reference to `pthread_create'
You need to add the name of the library to the compilation command line
Say

gcc -o prog thread.c -lpthread

The #include in the source code is for the compiler, so it knows how to call the function correctly
The -lpthread on the command line is for the linker, so it can find the actual implementation of the function.

> rc = pthread_create(&threads, NULL, (void *)cb, NULL);
If you declare your cb function like this, then there is no need for the cast when you call pthread_create()

void *cb(void *p)
{
   printf("%s", "hi");
   return NULL;
}