busybox/procps/pstree.c

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/*
* pstree.c - display process tree
*
* Copyright (C) 1993-2002 Werner Almesberger
* Copyright (C) 2002-2009 Craig Small
* Copyright (C) 2010 Lauri Kasanen
*
* Based on pstree (PSmisc) 22.13.
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
//config:config PSTREE
//config: bool "pstree"
//config: default y
//config: help
//config: Display a tree of processes.
//applet:IF_PSTREE(APPLET(pstree, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_PSTREE) += pstree.o
//usage:#define pstree_trivial_usage
//usage: "[-p] [PID|USER]"
//usage:#define pstree_full_usage "\n\n"
//usage: "Display process tree, optionally start from USER or PID\n"
//usage: "\n -p Show pids"
#include "libbb.h"
#define PROC_BASE "/proc"
#define OPT_PID (1 << 0)
struct child;
typedef struct proc {
char comm[COMM_LEN + 1];
// char flags; - unused, delete?
pid_t pid;
uid_t uid;
struct child *children;
struct proc *parent;
struct proc *next;
} PROC;
/* For flags above */
//#define PFLAG_THREAD 0x01
typedef struct child {
PROC *child;
struct child *next;
} CHILD;
#define empty_2 " "
#define branch_2 "|-"
#define vert_2 "| "
#define last_2 "`-"
#define single_3 "---"
#define first_3 "-+-"
struct globals {
/* 0-based. IOW: the number of chars we printed on current line */
unsigned cur_x;
unsigned output_width;
/* The buffers will be dynamically increased in size as needed */
unsigned capacity;
unsigned *width;
uint8_t *more;
PROC *list;
smallint dumped; /* used by dump_by_user */
};
#define G (*ptr_to_globals)
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)
/*
* Allocates additional buffer space for width and more as needed.
* The first call will allocate the first buffer.
*
* bufindex the index that will be used after the call to this function.
*/
static void ensure_buffer_capacity(int bufindex)
{
if (bufindex >= G.capacity) {
G.capacity += 0x100;
G.width = xrealloc(G.width, G.capacity * sizeof(G.width[0]));
G.more = xrealloc(G.more, G.capacity * sizeof(G.more[0]));
}
}
/* NB: this function is never called with "bad" chars
* (control chars or chars >= 0x7f)
*/
static void out_char(char c)
{
G.cur_x++;
if (G.cur_x > G.output_width)
return;
if (G.cur_x == G.output_width)
c = '+';
putchar(c);
}
/* NB: this function is never called with "bad" chars
* (control chars or chars >= 0x7f)
*/
static void out_string(const char *str)
{
while (*str)
out_char(*str++);
}
static void out_newline(void)
{
putchar('\n');
G.cur_x = 0;
}
static PROC *find_proc(pid_t pid)
{
PROC *walk;
for (walk = G.list; walk; walk = walk->next)
if (walk->pid == pid)
break;
return walk;
}
static PROC *new_proc(const char *comm, pid_t pid, uid_t uid)
{
PROC *new = xzalloc(sizeof(*new));
strcpy(new->comm, comm);
new->pid = pid;
new->uid = uid;
new->next = G.list;
G.list = new;
return G.list;
}
static void add_child(PROC *parent, PROC *child)
{
CHILD *new, **walk;
int cmp;
new = xmalloc(sizeof(*new));
new->child = child;
for (walk = &parent->children; *walk; walk = &(*walk)->next) {
cmp = strcmp((*walk)->child->comm, child->comm);
if (cmp > 0)
break;
if (cmp == 0 && (*walk)->child->uid > child->uid)
break;
}
new->next = *walk;
*walk = new;
}
static void add_proc(const char *comm, pid_t pid, pid_t ppid,
uid_t uid /*, char isthread*/)
{
PROC *this, *parent;
this = find_proc(pid);
if (!this)
this = new_proc(comm, pid, uid);
else {
strcpy(this->comm, comm);
this->uid = uid;
}
if (pid == ppid)
ppid = 0;
// if (isthread)
// this->flags |= PFLAG_THREAD;
parent = find_proc(ppid);
if (!parent)
parent = new_proc("?", ppid, 0);
add_child(parent, this);
this->parent = parent;
}
static int tree_equal(const PROC *a, const PROC *b)
{
const CHILD *walk_a, *walk_b;
if (strcmp(a->comm, b->comm) != 0)
return 0;
if ((option_mask32 /*& OPT_PID*/) && a->pid != b->pid)
return 0;
for (walk_a = a->children, walk_b = b->children;
walk_a && walk_b;
walk_a = walk_a->next, walk_b = walk_b->next
) {
if (!tree_equal(walk_a->child, walk_b->child))
return 0;
}
return !(walk_a || walk_b);
}
static int out_args(const char *mystr)
{
const char *here;
int strcount = 0;
char tmpstr[5];
for (here = mystr; *here; here++) {
if (*here == '\\') {
out_string("\\\\");
strcount += 2;
} else if (*here >= ' ' && *here < 0x7f) {
out_char(*here);
strcount++;
} else {
sprintf(tmpstr, "\\%03o", (unsigned char) *here);
out_string(tmpstr);
strcount += 4;
}
}
return strcount;
}
static void
dump_tree(PROC *current, int level, int rep, int leaf, int last, int closing)
{
CHILD *walk, *next, **scan;
int lvl, i, add, offset, count, comm_len, first;
char tmp[sizeof(int)*3 + 4];
if (!current)
return;
if (!leaf) {
for (lvl = 0; lvl < level; lvl++) {
i = G.width[lvl] + 1;
while (--i >= 0)
out_char(' ');
if (lvl == level - 1) {
if (last) {
out_string(last_2);
} else {
out_string(branch_2);
}
} else {
if (G.more[lvl + 1]) {
out_string(vert_2);
} else {
out_string(empty_2);
}
}
}
}
add = 0;
if (rep > 1) {
add += sprintf(tmp, "%d*[", rep);
out_string(tmp);
}
comm_len = out_args(current->comm);
if (option_mask32 /*& OPT_PID*/) {
comm_len += sprintf(tmp, "(%d)", (int)current->pid);
out_string(tmp);
}
offset = G.cur_x;
if (!current->children) {
while (closing--)
out_char(']');
out_newline();
}
ensure_buffer_capacity(level);
G.more[level] = !last;
G.width[level] = comm_len + G.cur_x - offset + add;
if (G.cur_x >= G.output_width) {
//out_string(first_3); - why? it won't print anything
//out_char('+');
out_newline();
return;
}
first = 1;
for (walk = current->children; walk; walk = next) {
count = 0;
next = walk->next;
scan = &walk->next;
while (*scan) {
if (!tree_equal(walk->child, (*scan)->child))
scan = &(*scan)->next;
else {
if (next == *scan)
next = (*scan)->next;
count++;
*scan = (*scan)->next;
}
}
if (first) {
out_string(next ? first_3 : single_3);
first = 0;
}
dump_tree(walk->child, level + 1, count + 1,
walk == current->children, !next,
closing + (count ? 1 : 0));
}
}
static void dump_by_user(PROC *current, uid_t uid)
{
const CHILD *walk;
if (!current)
return;
if (current->uid == uid) {
if (G.dumped)
putchar('\n');
dump_tree(current, 0, 1, 1, 1, 0);
G.dumped = 1;
return;
}
for (walk = current->children; walk; walk = walk->next)
dump_by_user(walk->child, uid);
}
#if ENABLE_FEATURE_SHOW_THREADS
static void handle_thread(const char *comm, pid_t pid, pid_t ppid, uid_t uid)
{
char threadname[COMM_LEN + 2];
sprintf(threadname, "{%.*s}", COMM_LEN - 2, comm);
add_proc(threadname, pid, ppid, uid/*, 1*/);
}
#endif
static void mread_proc(void)
{
procps_status_t *p = NULL;
pid_t parent = 0;
int flags = PSSCAN_COMM | PSSCAN_PID | PSSCAN_PPID | PSSCAN_UIDGID | PSSCAN_TASKS;
while ((p = procps_scan(p, flags)) != NULL) {
#if ENABLE_FEATURE_SHOW_THREADS
if (p->pid != p->main_thread_pid)
handle_thread(p->comm, p->pid, parent, p->uid);
else
#endif
{
add_proc(p->comm, p->pid, p->ppid, p->uid/*, 0*/);
parent = p->pid;
}
}
}
int pstree_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int pstree_main(int argc UNUSED_PARAM, char **argv)
{
pid_t pid = 1;
long uid = 0;
INIT_G();
get_terminal_width_height(0, &G.output_width, NULL);
opt_complementary = "?1";
getopt32(argv, "p");
argv += optind;
if (argv[0]) {
if (argv[0][0] >= '0' && argv[0][0] <= '9') {
pid = xatoi(argv[0]);
} else {
uid = xuname2uid(argv[0]);
}
}
mread_proc();
if (!uid)
dump_tree(find_proc(pid), 0, 1, 1, 1, 0);
else {
dump_by_user(find_proc(1), uid);
if (!G.dumped) {
bb_error_msg_and_die("no processes found");
}
}
if (ENABLE_FEATURE_CLEAN_UP) {
free(G.width);
free(G.more);
}
return 0;
}