1 files changed, 406 insertions, 0 deletions

diff --git a/procps/pstree.c b/procps/pstree.c
new file mode 100644
index 000000000..180d0939a
--- /dev/null
+++ b/procps/pstree.c
@@ -0,0 +1,406 @@
+/*
+ * 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 {
+        /* 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);
+}
+
+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();
+
+        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;
+}