plan9fox/sys/src/cmd/pstree.c

191 lines
2.5 KiB
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#include <u.h>
#include <libc.h>
enum { NBUCKETS = 1024 };
typedef struct Proc Proc;
typedef struct Bucket Bucket;
struct Proc {
int pid;
Proc *first, *last, *parent, *next;
Proc *bnext;
};
struct Bucket {
Proc *first, *last;
} buck[NBUCKETS];
Proc *
getproc(int pid)
{
Proc *p;
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for(p = buck[pid % NBUCKETS].first; p; p = p->bnext)
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if(p->pid == pid)
return p;
return nil;
}
void
addproc(int pid)
{
Proc *p;
Bucket *b;
p = mallocz(sizeof(*p), 1);
if(p == nil)
sysfatal("malloc: %r");
p->pid = pid;
b = buck + pid % NBUCKETS;
if(b->first != nil)
b->last->bnext = p;
else
b->first = p;
b->last = p;
}
int
theppid(int pid)
{
char *file;
int fd;
char buf[12];
int ppid;
file = smprint("/proc/%d/ppid", pid);
fd = open(file, OREAD);
free(file);
if(fd < 0)
return 0;
ppid = 0;
if(read(fd, buf, sizeof buf) >= 0)
ppid = atoi(buf);
close(fd);
return ppid;
}
void
addppid(int pid)
{
int ppid;
Proc *p, *par;
p = getproc(pid);
ppid = theppid(pid);
par = getproc(ppid);
if(par == nil)
par = getproc(0);
p->parent = par;
if(par->first != nil)
par->last->next = p;
else
par->first = p;
par->last = p;
}
void
addprocs(void)
{
int fd, rc, i;
Dir *d;
fd = open("/proc", OREAD);
if(fd < 0)
sysfatal("open: %r");
rc = dirreadall(fd, &d);
if(rc < 0)
sysfatal("dirreadall: %r");
close(fd);
for(i = 0; i < rc; i++)
if(d[i].mode & DMDIR)
addproc(atoi(d[i].name));
for(i = 0; i < rc; i++)
if(d[i].mode & DMDIR)
addppid(atoi(d[i].name));
free(d);
}
Rune buf[512];
int
readout(char *file)
{
int fd, rc, n;
char b[512];
fd = open(file, OREAD);
free(file);
if(fd < 0)
return -1;
n = 0;
while(rc = read(fd, b, 512), rc > 0) {
write(1, b, rc);
n += rc;
}
close(fd);
return n;
}
void
printargs(int pid)
{
char *file;
char b[28], *p;
int fd;
if(pid == 0)
return;
if(readout(smprint("/proc/%d/args", pid)) > 0)
return;
file = smprint("/proc/%d/status", pid);
fd = open(file, OREAD);
free(file);
if(fd < 0)
return;
memset(b, 0, sizeof b);
if(read(fd, b, 27) <= 0)
return;
p = b + strlen(b) - 1;
while(*p == ' ')
*p-- = 0;
print("%s", b);
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close(fd);
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}
void
descend(Proc *p, Rune *r)
{
Rune last;
Proc *q;
last = *--r;
*r = last == L' ' ? L'' : L'';
print("%S", buf);
printargs(p->pid);
print(" [%d]\n", p->pid);
*r = last;
*++r = L'';
for(q = p->first; q; q = q->next) {
if(q->next == nil)
*r = L' ';
descend(q, r + 1);
}
*r = 0;
}
void
printprocs(void)
{
descend(getproc(0), buf);
}
void
main()
{
addproc(0);
addprocs();
printprocs();
}