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#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
int main( int argc, char *argv[] )
{
int numchildren=1;
if( argc==2 ) {
numchildren=strtoul( argv[1], 0, NULL );
}
for( int i=0; i<numchildren; ++i ) {
pid_t child=fork();
if( child==0 ) {
// We are the child
int exitcode=getpid()%253;
printf("Child %d(%d) exit with code 0x%x\n", i+1, getpid(), exitcode );
exit(exitcode);
} else if( child==-1 ) {
perror("Failed to fork");
}
}
sleep(1);
for( int i=0; i<numchildren; ++i ) {
int status;
pid_t process=wait(&status);
if( process<0 ) {
perror("wait failed");
} else {
printf("PID %d returned 0x%x\n", process, status);
}
}
int status;
pid_t process=wait(&status);
if( process<0 ) {
perror("Second wait failed");
} else {
printf("PID %d returned 0x%x\n", process, status);
}
return 0;
}
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