procps/pstree.c

   1 /*
   2  * pstree.c - display process tree
   3  *
   4  * Copyright (C) 1993-2002 Werner Almesberger
   5  * Copyright (C) 2002-2009 Craig Small
   6  * Copyright (C) 2010 Lauri Kasanen
   7  *
   8  * Based on pstree (PSmisc) 22.13.
   9  *
  10  * Licensed under GPLv2, see file LICENSE in this source tree.
  11  */
  12
  13 //config:config PSTREE
  14 //config:       bool "pstree"
  15 //config:       default y
  16 //config:       help
  17 //config:         Display a tree of processes.
  18
  19 //applet:IF_PSTREE(APPLET(pstree, _BB_DIR_USR_BIN, _BB_SUID_DROP))
  20
  21 //kbuild:lib-$(CONFIG_PSTREE) += pstree.o
  22
  23 //usage:#define pstree_trivial_usage
  24 //usage:        "[-p] [PID|USER]"
  25 //usage:#define pstree_full_usage "\n\n"
  26 //usage:       "Display process tree, optionally start from USER or PID\n"
  27 //usage:     "\nOptions:"
  28 //usage:     "\n        -p      Show pids"
  29
  30 #include "libbb.h"
  31
  32 #define PROC_BASE "/proc"
  33
  34 #define OPT_PID  (1 << 0)
  35
  36 struct child;
  37
  38 typedef struct proc {
  39         char comm[COMM_LEN + 1];
  40 //      char flags; - unused, delete?
  41         pid_t pid;
  42         uid_t uid;
  43         struct child *children;
  44         struct proc *parent;
  45         struct proc *next;
  46 } PROC;
  47
  48 /* For flags above */
  49 //#define PFLAG_THREAD  0x01
  50
  51 typedef struct child {
  52         PROC *child;
  53         struct child *next;
  54 } CHILD;
  55
  56 #define empty_2  "  "
  57 #define branch_2 "|-"
  58 #define vert_2   "| "
  59 #define last_2   "`-"
  60 #define single_3 "---"
  61 #define first_3  "-+-"
  62
  63 struct globals {
  64         /* 0-based. IOW: the number of chars we printer on current line */
  65         unsigned cur_x;
  66         unsigned output_width;
  67
  68         /* The buffers will be dynamically increased in size as needed */
  69         unsigned capacity;
  70         unsigned *width;
  71         uint8_t *more;
  72
  73         PROC *list;
  74
  75         smallint dumped; /* used by dump_by_user */
  76 };
  77 #define G (*ptr_to_globals)
  78 #define INIT_G() do { \
  79         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
  80 } while (0)
  81
  82
  83 /*
  84  * Allocates additional buffer space for width and more as needed.
  85  * The first call will allocate the first buffer.
  86  *
  87  * bufindex  the index that will be used after the call to this function.
  88  */
  89 static void ensure_buffer_capacity(int bufindex)
  90 {
  91         if (bufindex >= G.capacity) {
  92                 G.capacity += 0x100;
  93                 G.width = xrealloc(G.width, G.capacity * sizeof(G.width[0]));
  94                 G.more = xrealloc(G.more, G.capacity * sizeof(G.more[0]));
  95         }
  96 }
  97
  98 #if ENABLE_FEATURE_CLEAN_UP
  99 static void maybe_free_buffers(void)
 100 {
 101         free(G.width);
 102         free(G.more);
 103 }
 104 #else
 105 # define maybe_free_buffers() ((void)0)
 106 #endif
 107
 108 /* NB: this function is never called with "bad" chars
 109  * (control chars or chars >= 0x7f)
 110  */
 111 static void out_char(char c)
 112 {
 113         G.cur_x++;
 114         if (G.cur_x == G.output_width)
 115                 c = '+';
 116         if (G.cur_x <= G.output_width)
 117                 putchar(c);
 118 }
 119
 120 /* NB: this function is never called with "bad" chars
 121  * (control chars or chars >= 0x7f)
 122  */
 123 static void out_string(const char *str)
 124 {
 125         while (*str)
 126                 out_char(*str++);
 127 }
 128
 129 static void out_newline(void)
 130 {
 131         putchar('\n');
 132         G.cur_x = 0;
 133 }
 134
 135 static PROC *find_proc(pid_t pid)
 136 {
 137         PROC *walk;
 138
 139         for (walk = G.list; walk; walk = walk->next)
 140                 if (walk->pid == pid)
 141                         break;
 142
 143         return walk;
 144 }
 145
 146 static PROC *new_proc(const char *comm, pid_t pid, uid_t uid)
 147 {
 148         PROC *new = xzalloc(sizeof(*new));
 149
 150         strcpy(new->comm, comm);
 151         new->pid = pid;
 152         new->uid = uid;
 153         new->next = G.list;
 154
 155         G.list = new;
 156         return G.list;
 157 }
 158
 159 static void add_child(PROC *parent, PROC *child)
 160 {
 161         CHILD *new, **walk;
 162         int cmp;
 163
 164         new = xmalloc(sizeof(*new));
 165
 166         new->child = child;
 167         for (walk = &parent->children; *walk; walk = &(*walk)->next) {
 168                 cmp = strcmp((*walk)->child->comm, child->comm);
 169                 if (cmp > 0)
 170                         break;
 171                 if (cmp == 0 && (*walk)->child->uid > child->uid)
 172                         break;
 173         }
 174         new->next = *walk;
 175         *walk = new;
 176 }
 177
 178 static void add_proc(const char *comm, pid_t pid, pid_t ppid,
 179                         uid_t uid /*, char isthread*/)
 180 {
 181         PROC *this, *parent;
 182
 183         this = find_proc(pid);
 184         if (!this)
 185                 this = new_proc(comm, pid, uid);
 186         else {
 187                 strcpy(this->comm, comm);
 188                 this->uid = uid;
 189         }
 190
 191         if (pid == ppid)
 192                 ppid = 0;
 193 //      if (isthread)
 194 //              this->flags |= PFLAG_THREAD;
 195
 196         parent = find_proc(ppid);
 197         if (!parent)
 198                 parent = new_proc("?", ppid, 0);
 199
 200         add_child(parent, this);
 201         this->parent = parent;
 202 }
 203
 204 static int tree_equal(const PROC *a, const PROC *b)
 205 {
 206         const CHILD *walk_a, *walk_b;
 207
 208         if (strcmp(a->comm, b->comm) != 0)
 209                 return 0;
 210         if ((option_mask32 /*& OPT_PID*/) && a->pid != b->pid)
 211                 return 0;
 212
 213         for (walk_a = a->children, walk_b = b->children;
 214           walk_a && walk_b;
 215           walk_a = walk_a->next, walk_b = walk_b->next
 216         ) {
 217                 if (!tree_equal(walk_a->child, walk_b->child))
 218                         return 0;
 219         }
 220
 221         return !(walk_a || walk_b);
 222 }
 223
 224 static int out_args(const char *mystr)
 225 {
 226         const char *here;
 227         int strcount = 0;
 228         char tmpstr[5];
 229
 230         for (here = mystr; *here; here++) {
 231                 if (*here == '\\') {
 232                         out_string("\\\\");
 233                         strcount += 2;
 234                 } else if (*here >= ' ' && *here < 0x7f) {
 235                         out_char(*here);
 236                         strcount++;
 237                 } else {
 238                         sprintf(tmpstr, "\\%03o", (unsigned char) *here);
 239                         out_string(tmpstr);
 240                         strcount += 4;
 241                 }
 242         }
 243
 244         return strcount;
 245 }
 246
 247 static void
 248 dump_tree(PROC *current, int level, int rep, int leaf, int last, int closing)
 249 {
 250         CHILD *walk, *next, **scan;
 251         int lvl, i, add, offset, count, comm_len, first;
 252         char tmp[sizeof(int)*3 + 4];
 253
 254         if (!current)
 255                 return;
 256
 257         if (!leaf) {
 258                 for (lvl = 0; lvl < level; lvl++) {
 259                         i = G.width[lvl] + 1;
 260                         while (--i >= 0)
 261                                 out_char(' ');
 262
 263                         if (lvl == level - 1) {
 264                                 if (last) {
 265                                         out_string(last_2);
 266                                 } else {
 267                                         out_string(branch_2);
 268                                 }
 269                         } else {
 270                                 if (G.more[lvl + 1]) {
 271                                         out_string(vert_2);
 272                                 } else {
 273                                         out_string(empty_2);
 274                                 }
 275                         }
 276                 }
 277         }
 278
 279         add = 0;
 280         if (rep > 1) {
 281                 add += sprintf(tmp, "%d*[", rep);
 282                 out_string(tmp);
 283         }
 284         comm_len = out_args(current->comm);
 285         if (option_mask32 /*& OPT_PID*/) {
 286                 comm_len += sprintf(tmp, "(%d)", (int)current->pid);
 287                 out_string(tmp);
 288         }
 289         offset = G.cur_x;
 290
 291         if (!current->children) {
 292                 while (closing--)
 293                         out_char(']');
 294                 out_newline();
 295         }
 296         ensure_buffer_capacity(level);
 297         G.more[level] = !last;
 298
 299         G.width[level] = comm_len + G.cur_x - offset + add;
 300         if (G.cur_x >= G.output_width) {
 301                 //out_string(first_3); - why? it won't print anything
 302                 //out_char('+');
 303                 out_newline();
 304                 return;
 305         }
 306
 307         first = 1;
 308         for (walk = current->children; walk; walk = next) {
 309                 count = 0;
 310                 next = walk->next;
 311                 scan = &walk->next;
 312                 while (*scan) {
 313                         if (!tree_equal(walk->child, (*scan)->child))
 314                                 scan = &(*scan)->next;
 315                         else {
 316                                 if (next == *scan)
 317                                         next = (*scan)->next;
 318                                 count++;
 319                                 *scan = (*scan)->next;
 320                         }
 321                 }
 322                 if (first) {
 323                         out_string(next ? first_3 : single_3);
 324                         first = 0;
 325                 }
 326
 327                 dump_tree(walk->child, level + 1, count + 1,
 328                                 walk == current->children, !next,
 329                                 closing + (count ? 1 : 0));
 330         }
 331 }
 332
 333 static void dump_by_user(PROC *current, uid_t uid)
 334 {
 335         const CHILD *walk;
 336
 337         if (!current)
 338                 return;
 339
 340         if (current->uid == uid) {
 341                 if (G.dumped)
 342                         putchar('\n');
 343                 dump_tree(current, 0, 1, 1, 1, 0);
 344                 G.dumped = 1;
 345                 return;
 346         }
 347         for (walk = current->children; walk; walk = walk->next)
 348                 dump_by_user(walk->child, uid);
 349 }
 350
 351 static void handle_thread(const char *comm, pid_t pid, pid_t ppid, uid_t uid)
 352 {
 353         char threadname[COMM_LEN + 2];
 354         sprintf(threadname, "{%.*s}", COMM_LEN - 2, comm);
 355         add_proc(threadname, pid, ppid, uid/*, 1*/);
 356 }
 357
 358 static void mread_proc(void)
 359 {
 360         procps_status_t *p = NULL;
 361         pid_t parent = 0;
 362         int flags = PSSCAN_COMM | PSSCAN_PID | PSSCAN_PPID | PSSCAN_UIDGID | PSSCAN_TASKS;
 363
 364         while ((p = procps_scan(p, flags)) != NULL) {
 365 #if ENABLE_FEATURE_SHOW_THREADS
 366                 if (p->pid != p->main_thread_pid)
 367                         handle_thread(p->comm, p->pid, parent, p->uid);
 368                 else
 369 #endif
 370                 {
 371                         add_proc(p->comm, p->pid, p->ppid, p->uid/*, 0*/);
 372                         parent = p->pid;
 373                 }
 374         }
 375 }
 376
 377 int pstree_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 378 int pstree_main(int argc UNUSED_PARAM, char **argv)
 379 {
 380         pid_t pid = 1;
 381         long uid = 0;
 382
 383         INIT_G();
 384
 385         get_terminal_width_height(1, &G.output_width, NULL);
 386
 387         getopt32(argv, "p");
 388         argv += optind;
 389
 390         if (argv[0]) {
 391                 if (argv[1])
 392                         bb_show_usage();
 393                 if (argv[0][0] >= '0' && argv[0][0] <= '9') {
 394                         pid = xatoi(argv[0]);
 395                 } else {
 396                         uid = xuname2uid(argv[0]);
 397                 }
 398         }
 399
 400         mread_proc();
 401
 402         if (!uid)
 403                 dump_tree(find_proc(pid), 0, 1, 1, 1, 0);
 404         else {
 405                 dump_by_user(find_proc(1), uid);
 406                 if (!G.dumped) {
 407                         bb_error_msg_and_die("no processes found");
 408                 }
 409         }
 410
 411         maybe_free_buffers();
 412         return 0;
 413 }