#include <u.h>#include <libc.h>#include <bio.h> void	ps(char*);void	error(char*);int	cmp(void*, void*); Biobuf	bout;int	pflag;int	aflag; voidmain(int argc, char *argv[]){	int fd, i, tot, none = 1;	Dir *dir, **mem;  	ARGBEGIN {	case 'a':		aflag++;		break;	case 'p':		pflag++;		break;	} ARGEND;	Binit(&bout, 1, OWRITE);	if(chdir("/proc")==-1)		error("/proc");	fd=open(".", OREAD);	if(fd<0)		error("/proc");	tot = dirreadall(fd, &dir);	if(tot <= 0){		fprint(2, "ps: empty directory /proc\n");		exits("empty");	}	mem = malloc(tot*sizeof(Dir*));	for(i=0; i<tot; i++)		mem[i] = dir++; 	qsort(mem, tot, sizeof(Dir*), cmp);	for(i=0; i<tot; i++){		ps(mem[i]->name);		none = 0;	} 	if(none)		error("no processes; bad #p");	exits(0);} voidps(char *s){	int i, n, fd;	char buf[64];	int basepri, pri;	long utime, stime, size;	char pbuf[8];#define NAMELEN 28	char status[2*NAMELEN+12+9*12+1];	char args[256];	char *p; 	sprint(buf, "%s/status", s);	fd = open(buf, OREAD);	if(fd<0)		return;	n = read(fd, status, sizeof status-1);	close(fd);	if(n <= 0)		return;	status[n] = '\0';	p = strchr(status, ' ');	if(!p)		return;	*p = 0;	p = strchr(status+NAMELEN, ' ');	if(!p)		return;	*p = 0;	status[2*NAMELEN+12-1] = 0;	utime = atol(status+2*NAMELEN+12)/1000;	stime = atol(status+2*NAMELEN+12+1*12)/1000;	size  = atol(status+2*NAMELEN+12+6*12);	if(pflag){		basepri = atol(status+2*NAMELEN+12+7*12);		pri = atol(status+2*NAMELEN+12+8*12);		sprint(pbuf, " %2d %2d", basepri, pri);	} else		pbuf[0] = 0;	Bprint(&bout, "%-10s %8s %4ld:%.2ld %3ld:%.2ld%s %7ldK %-.8s ",			status+NAMELEN,			s,			utime/60, utime%60,			stime/60, stime%60,			pbuf,			size,			status+2*NAMELEN); 	if(aflag == 0){    Noargs:		Bprint(&bout, "%s\n", status);		return;	} 	sprint(buf, "%s/args", s);	fd = open(buf, OREAD);	if(fd < 0)		goto Badargs;	n = read(fd, args, sizeof args-1);	close(fd);	if(n < 0)		goto Badargs;	if(n == 0)		goto Noargs;	args[n] = '\0';	for(i=0; i<n; i++)		if(args[i] == '\n')			args[i] = ' ';	Bprint(&bout, "%s\n", args);	return;     Badargs:	Bprint(&bout, "%s ?\n", status);} voiderror(char *s){	fprint(2, "ps: %s: ", s);	perror("error");	exits(s);} intcmp(void *va, void *vb){	Dir **a, **b; 	a = va;	b = vb;	return atoi((*a)->name) - atoi((*b)->name);}