proc.c

早期freebsd实现

    cmdp = command;
    cmdlen = 0;
    padd(t);
    *cmdp++ = 0;
    if (t->t_dflg & F_PIPEOUT) {
	pp->p_flags |= PPOU;
	if (t->t_dflg & F_STDERR)
	    pp->p_flags |= PERR;
    }
    pp->p_command = Strsave(command);
    if (pcurrjob) {
	struct process *fp;

	/* careful here with interrupt level */
	pp->p_cwd = 0;
	pp->p_index = pcurrjob->p_index;
	pp->p_friends = pcurrjob;
	pp->p_jobid = pcurrjob->p_pid;
	for (fp = pcurrjob; fp->p_friends != pcurrjob; fp = fp->p_friends)
	    continue;
	fp->p_friends = pp;
    }
    else {
	pcurrjob = pp;
	pp->p_jobid = pid;
	pp->p_friends = pp;
	pp->p_cwd = dcwd;
	dcwd->di_count++;
	if (pmaxindex < BIGINDEX)
	    pp->p_index = ++pmaxindex;
	else {
	    struct process *np;

	    for (i = 1;; i++) {
		for (np = proclist.p_next; np; np = np->p_next)
		    if (np->p_index == i)
			goto tryagain;
		pp->p_index = i;
		if (i > pmaxindex)
		    pmaxindex = i;
		break;
	tryagain:;
	    }
	}
	if (pcurrent == NULL)
	    pcurrent = pp;
	else if (pprevious == NULL)
	    pprevious = pp;
    }
    pp->p_next = proclist.p_next;
    proclist.p_next = pp;
    (void) gettimeofday(&pp->p_btime, NULL);
}

static void
padd(t)
    register struct command *t;
{
    Char  **argp;

    if (t == 0)
	return;
    switch (t->t_dtyp) {

    case NODE_PAREN:
	pads(STRLparensp);
	padd(t->t_dspr);
	pads(STRspRparen);
	break;

    case NODE_COMMAND:
	for (argp = t->t_dcom; *argp; argp++) {
	    pads(*argp);
	    if (argp[1])
		pads(STRspace);
	}
	break;

    case NODE_OR:
    case NODE_AND:
    case NODE_PIPE:
    case NODE_LIST:
	padd(t->t_dcar);
	switch (t->t_dtyp) {
	case NODE_OR:
	    pads(STRspor2sp);
	    break;
	case NODE_AND:
	    pads(STRspand2sp);
	    break;
	case NODE_PIPE:
	    pads(STRsporsp);
	    break;
	case NODE_LIST:
	    pads(STRsemisp);
	    break;
	}
	padd(t->t_dcdr);
	return;
    }
    if ((t->t_dflg & F_PIPEIN) == 0 && t->t_dlef) {
	pads((t->t_dflg & F_READ) ? STRspLarrow2sp : STRspLarrowsp);
	pads(t->t_dlef);
    }
    if ((t->t_dflg & F_PIPEOUT) == 0 && t->t_drit) {
	pads((t->t_dflg & F_APPEND) ? STRspRarrow2 : STRspRarrow);
	if (t->t_dflg & F_STDERR)
	    pads(STRand);
	pads(STRspace);
	pads(t->t_drit);
    }
}

static void
pads(cp)
    Char   *cp;
{
    register int i;

    /*
     * Avoid the Quoted Space alias hack! Reported by:
     * [e-mail] (Sam Horrocks)
     */
    if (cp[0] == STRQNULL[0])
	cp++;

    i = Strlen(cp);

    if (cmdlen >= PMAXLEN)
	return;
    if (cmdlen + i >= PMAXLEN) {
	(void) Strcpy(cmdp, STRsp3dots);
	cmdlen = PMAXLEN;
	cmdp += 4;
	return;
    }
    (void) Strcpy(cmdp, cp);
    cmdp += i;
    cmdlen += i;
}

/*
 * psavejob - temporarily save the current job on a one level stack
 *	so another job can be created.  Used for { } in exp6
 *	and `` in globbing.
 */
void
psavejob()
{

    pholdjob = pcurrjob;
    pcurrjob = NULL;
}

/*
 * prestjob - opposite of psavejob.  This may be missed if we are interrupted
 *	somewhere, but pendjob cleans up anyway.
 */
void
prestjob()
{

    pcurrjob = pholdjob;
    pholdjob = NULL;
}

/*
 * pendjob - indicate that a job (set of commands) has been completed
 *	or is about to begin.
 */
void
pendjob()
{
    register struct process *pp, *tp;

    if (pcurrjob && (pcurrjob->p_flags & (PFOREGND | PSTOPPED)) == 0) {
	pp = pcurrjob;
	while (pp->p_pid != pp->p_jobid)
	    pp = pp->p_friends;
	(void) fprintf(cshout, "[%d]", pp->p_index);
	tp = pp;
	do {
	    (void) fprintf(cshout, " %d", pp->p_pid);
	    pp = pp->p_friends;
	} while (pp != tp);
	(void) fputc('\n', cshout);
    }
    pholdjob = pcurrjob = 0;
}

/*
 * pprint - print a job
 */
static int
pprint(pp, flag)
    register struct process *pp;
    bool    flag;
{
    register status, reason;
    struct process *tp;
    int     jobflags, pstatus;
    bool hadnl = 1;	/* did we just have a newline */
    char   *format;

    (void) fpurge(cshout);

    while (pp->p_pid != pp->p_jobid)
	pp = pp->p_friends;
    if (pp == pp->p_friends && (pp->p_flags & PPTIME)) {
	pp->p_flags &= ~PPTIME;
	pp->p_flags |= PTIME;
    }
    tp = pp;
    status = reason = -1;
    jobflags = 0;
    do {
	jobflags |= pp->p_flags;
	pstatus = pp->p_flags & PALLSTATES;
	if (tp != pp && !hadnl && !(flag & FANCY) &&
	    ((pstatus == status && pp->p_reason == reason) ||
	     !(flag & REASON))) {
	    (void) fputc(' ', cshout);
	    hadnl = 0;
	}
	else {
	    if (tp != pp && !hadnl) {
		(void) fputc('\n', cshout);
		hadnl = 1;
	    }
	    if (flag & NUMBER) {
		if (pp == tp)
		    (void) fprintf(cshout, "[%d]%s %c ", pp->p_index,
			    pp->p_index < 10 ? " " : "",
			    pp == pcurrent ? '+' :
			    (pp == pprevious ? '-' : ' '));
		else
		    (void) fprintf(cshout, "       ");
		hadnl = 0;
	    }
	    if (flag & FANCY) {
		(void) fprintf(cshout, "%5d ", pp->p_pid);
		hadnl = 0;
	    }
	    if (flag & (REASON | AREASON)) {
		if (flag & NAME)
		    format = "%-23s";
		else
		    format = "%s";
		if (pstatus == status)
		    if (pp->p_reason == reason) {
			(void) fprintf(cshout, format, "");
			hadnl = 0;
			goto prcomd;
		    }
		    else
			reason = pp->p_reason;
		else {
		    status = pstatus;
		    reason = pp->p_reason;
		}
		switch (status) {

		case PRUNNING:
		    (void) fprintf(cshout, format, "Running ");
		    hadnl = 0;
		    break;

		case PINTERRUPTED:
		case PSTOPPED:
		case PSIGNALED:
                    /*
                     * tell what happened to the background job
                     * From: Michael Schroeder
                     * <[e-mail]>
                     */
                    if ((flag & REASON)
                        || ((flag & AREASON)
                            && reason != SIGINT
                            && (reason != SIGPIPE
                                || (pp->p_flags & PPOU) == 0))) {
			(void) fprintf(cshout, format,
				       sys_siglist[(unsigned char)
						   pp->p_reason]);
			hadnl = 0;
		    }
		    break;

		case PNEXITED:
		case PAEXITED:
		    if (flag & REASON) {
			if (pp->p_reason)
			    (void) fprintf(cshout, "Exit %-18d", pp->p_reason);
			else
			    (void) fprintf(cshout, format, "Done");
			hadnl = 0;
		    }
		    break;

		default:
		    (void) fprintf(csherr, "BUG: status=%-9o", status);
		}
	    }
	}
prcomd:
	if (flag & NAME) {
	    (void) fprintf(cshout, "%s", vis_str(pp->p_command));
	    if (pp->p_flags & PPOU)
		(void) fprintf(cshout, " |");
	    if (pp->p_flags & PERR)
		(void) fputc('&', cshout);
	    hadnl = 0;
	}
	if (flag & (REASON | AREASON) && pp->p_flags & PDUMPED) {
	    (void) fprintf(cshout, " (core dumped)");
	    hadnl = 0;
	}
	if (tp == pp->p_friends) {
	    if (flag & AMPERSAND) {
		(void) fprintf(cshout, " &");
		hadnl = 0;
	    }
	    if (flag & JOBDIR &&
		!eq(tp->p_cwd->di_name, dcwd->di_name)) {
		(void) fprintf(cshout, " (wd: ");
		dtildepr(value(STRhome), tp->p_cwd->di_name);
		(void) fputc(')', cshout);
		hadnl = 0;
	    }
	}
	if (pp->p_flags & PPTIME && !(status & (PSTOPPED | PRUNNING))) {
	    if (!hadnl)
		(void) fprintf(cshout, "\n\t");
	    prusage(&zru, &pp->p_rusage, &pp->p_etime,
		    &pp->p_btime);
	    hadnl = 1;
	}
	if (tp == pp->p_friends) {
	    if (!hadnl) {
		(void) fputc('\n', cshout);
		hadnl = 1;
	    }
	    if (flag & SHELLDIR && !eq(tp->p_cwd->di_name, dcwd->di_name)) {
		(void) fprintf(cshout, "(wd now: ");
		dtildepr(value(STRhome), dcwd->di_name);
		(void) fprintf(cshout, ")\n");
		hadnl = 1;
	    }
	}
    } while ((pp = pp->p_friends) != tp);
    if (jobflags & PTIME && (jobflags & (PSTOPPED | PRUNNING)) == 0) {
	if (jobflags & NUMBER)
	    (void) fprintf(cshout, "       ");
	ptprint(tp);
	hadnl = 1;
    }
    (void) fflush(cshout);
    return (jobflags);
}

static void
ptprint(tp)
    register struct process *tp;
{
    struct timeval tetime, diff;
    static struct timeval ztime;
    struct rusage ru;
    static struct rusage zru;
    register struct process *pp = tp;

    ru = zru;
    tetime = ztime;
    do {
	ruadd(&ru, &pp->p_rusage);
	tvsub(&diff, &pp->p_etime, &pp->p_btime);
	if (timercmp(&diff, &tetime, >))
	    tetime = diff;
    } while ((pp = pp->p_friends) != tp);
    prusage(&zru, &ru, &tetime, &ztime);
}

/*
 * dojobs - print all jobs
 */
void
/*ARGSUSED*/
dojobs(v, t)
    Char **v;
    struct command *t;
{
    register struct process *pp;
    register int flag = NUMBER | NAME | REASON;
    int     i;

    if (chkstop)
	chkstop = 2;
    if (*++v) {
	if (v[1] || !eq(*v, STRml))
	    stderror(ERR_JOBS);
	flag |= FANCY | JOBDIR;
    }
    for (i = 1; i <= pmaxindex; i++)
	for (pp = proclist.p_next; pp; pp = pp->p_next)
	    if (pp->p_index == i && pp->p_pid == pp->p_jobid) {
		pp->p_flags &= ~PNEEDNOTE;
		if (!(pprint(pp, flag) & (PRUNNING | PSTOPPED)))
		    pflush(pp);
		break;
	    }
}

/*
 * dofg - builtin - put the job into the foreground
 */
void
/*ARGSUSED*/
dofg(v, t)
    Char **v;
    struct command *t;
{
    register struct process *pp;

    okpcntl();
    ++v;
    do {
	pp = pfind(*v);
	pstart(pp, 1);
	pjwait(pp);
    } while (*v && *++v);
}

/*
 * %... - builtin - put the job into the foreground
 */
void
/*ARGSUSED*/
dofg1(v, t)
    Char **v;
    struct command *t;
{
    register struct process *pp;

    okpcntl();
    pp = pfind(v[0]);
    pstart(pp, 1);
    pjwait(pp);
}

/*
 * dobg - builtin - put the job into the background
 */
void
/*ARGSUSED*/
dobg(v, t)