how can I get user string input while the program is running? I want to break the while loop when user input "stop" to terminal. However, scanf or gets just wait for the input.
This is just an example that I want.
#include <stdio.h>
int main() {
int i=0;
while (1) {
//if ( userinput == "stop") break;
printf("printing..%d\n",i++);
}
return 0;
}
You can do it with fork() and kill(), child process handle printf(), parent process handle userinput, when user input stop, parent process kill child process.
The following code could work:
#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <unistd.h>
int main() {
pid_t child_pid = fork();
if (child_pid == 0) { // child
int i = 0;
for (;;) {
printf("printing..%d\n", i++);
}
} else {
char userinput[1024];
for (;;) {
fgets(userinput, sizeof(userinput), stdin);
if (strcmp(userinput, "stop\n") == 0) {
kill(child_pid, SIGSTOP);
break;
}
}
}
return 0;
}
