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| void do_bgfg(char **argv)
{
int pid,jid;
//int isjob = 0;
int bg = 0;
sigset_t mask_one,prev_one;
sigaddset(&mask_one,SIGCHLD);
if(argv[1] == NULL ){
printf("bg command requires PID or %%jobid argument\n");
return;
}
if((argv[1][0] != '%' && (argv[1][0] < '0' || argv[1][0] > '9' ))){
printf("%s: argument must be a PID or %%jobid\n",argv[0]);
return;
}
if(!strcmp(argv[0],"bg"))
bg = 1;
if(argv[1][0] != '%'){
pid = atoi(&argv[1][0]);
/*
if(pid == 0){
printf("%s: No such job\n",argv[1]);
return;
}
*/
struct job_t *j = getjobpid(jobs,pid);
if(!j)
{
printf("%s: No such job\n",argv[1]);
return;
}
//isjob = 1;
if(bg){
//printf("first\n");
j->state = BG;
printf("[%d] (%d) %s", j->jid, j->pid, j->cmdline);
killpg(pid,SIGCONT);
}else{
// 进入前要对sigchld信号进行屏蔽，否则可能死循环。
sigprocmask(SIG_BLOCK,&mask_one,&prev_one);
if(j->state == ST)
killpg(pid,SIGCONT);
j->state = FG;
waitfg(j->pid);
sigprocmask(SIG_SETMASK,&prev_one,NULL);
}
}else {
jid = atoi(&argv[1][1]);
/*
if(jid == 0){
printf("(%s): No such process\n",argv[1]);
return;
}
*/
struct job_t *j = getjobjid(jobs,jid);
if(!j){
printf("(%s): No such process\n",argv[1]);
return;
}
if(bg){
j->state = BG;
printf("[%d] (%d) %s", j->jid, j->pid, j->cmdline);
killpg(j->pid,SIGCONT);
}else{
// 进入前要对sigchld信号进行屏蔽，否则可能死循环。
//sigprocmask(SIG_BLOCK,&mask_one,&prev_one);
//printf("fg\n");
if(j->state== ST)
killpg(j->pid,SIGCONT);
j->state = FG;
waitfg(j->pid);
//sigprocmask(SIG_SETMASK,&prev_one,NULL);
}
}
return;
}
|
