pstree: new applet. +1664 bytes

   text    data     bss     dec     hex filename
 883379     936   17192  901507   dc183 busybox_old
 885043     936   17192  903171   dc803 busybox_unstripped

Signed-off-by: Lauri Kasanen <curaga@operamail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 415 insertions, 0 deletions

diff --git a/procps/pstree.c b/procps/pstree.c
new file mode 100644
index 0000000..f09e8da
--- /dev/null
+++ b/procps/pstree.c
@@ -0,0 +1,415 @@
+/*
+ * 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:     "\nOptions:"
+//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 {
+	PROC *list;
+
+	/* The buffers will be dynamically increased in size as needed */
+	unsigned capacity;
+	int *width;
+	int *more;
+
+// Disabled, since code is broken anyway and needs fixing
+//	unsigned output_width;
+	unsigned cur_x;
+	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]));
+	}
+}
+
+#if ENABLE_FEATURE_CLEAN_UP
+static void maybe_free_buffers(void)
+{
+	free(G.width);
+	free(G.more);
+}
+#else
+# define maybe_free_buffers() ((void)0)
+#endif
+
+/* 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)
+		putchar(c);
+//	else if (G.cur_x == G.output_width - 1)
+//		putchar('+');
+}
+
+/* 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 = 1;
+}
+
+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;
+
+	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);
+				}
+			}
+		}
+	}
+
+	if (rep < 2)
+		add = 0;
+	else {
+		add = printf("%d", rep) + 2;
+		out_string("*[");
+	}
+	comm_len = out_args(current->comm);
+	if (option_mask32 /*& OPT_PID*/) {
+		out_char('(');
+		comm_len += printf("%d", (int)current->pid) + 2;
+		out_char(')');
+	}
+	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);
+//		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);
+}
+
+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*/);
+}
+
+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();
+	G.cur_x = 1;
+
+//	get_terminal_width_height(1, &G.output_width, NULL);
+
+	getopt32(argv, "p");
+	argv += optind;
+
+	if (argv[0]) {
+		if (argv[1])
+			bb_show_usage();
+		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");
+		}
+	}
+
+	maybe_free_buffers();
+	return 0;
+}