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 printed 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 /* NB: this function is never called with "bad" chars
  99  * (control chars or chars >= 0x7f)
 100  */
 101 static void out_char(char c)
 102 {
 103         G.cur_x++;
 104         if (G.cur_x > G.output_width)
 105                 return;
 106         if (G.cur_x == G.output_width)
 107                 c = '+';
 108         putchar(c);
 109 }
 110
 111 /* NB: this function is never called with "bad" chars
 112  * (control chars or chars >= 0x7f)
 113  */
 114 static void out_string(const char *str)
 115 {
 116         while (*str)
 117                 out_char(*str++);
 118 }
 119
 120 static void out_newline(void)
 121 {
 122         putchar('\n');
 123         G.cur_x = 0;
 124 }
 125
 126 static PROC *find_proc(pid_t pid)
 127 {
 128         PROC *walk;
 129
 130         for (walk = G.list; walk; walk = walk->next)
 131                 if (walk->pid == pid)
 132                         break;
 133
 134         return walk;
 135 }
 136
 137 static PROC *new_proc(const char *comm, pid_t pid, uid_t uid)
 138 {
 139         PROC *new = xzalloc(sizeof(*new));
 140
 141         strcpy(new->comm, comm);
 142         new->pid = pid;
 143         new->uid = uid;
 144         new->next = G.list;
 145
 146         G.list = new;
 147         return G.list;
 148 }
 149
 150 static void add_child(PROC *parent, PROC *child)
 151 {
 152         CHILD *new, **walk;
 153         int cmp;
 154
 155         new = xmalloc(sizeof(*new));
 156
 157         new->child = child;
 158         for (walk = &parent->children; *walk; walk = &(*walk)->next) {
 159                 cmp = strcmp((*walk)->child->comm, child->comm);
 160                 if (cmp > 0)
 161                         break;
 162                 if (cmp == 0 && (*walk)->child->uid > child->uid)
 163                         break;
 164         }
 165         new->next = *walk;
 166         *walk = new;
 167 }
 168
 169 static void add_proc(const char *comm, pid_t pid, pid_t ppid,
 170                         uid_t uid /*, char isthread*/)
 171 {
 172         PROC *this, *parent;
 173
 174         this = find_proc(pid);
 175         if (!this)
 176                 this = new_proc(comm, pid, uid);
 177         else {
 178                 strcpy(this->comm, comm);
 179                 this->uid = uid;
 180         }
 181
 182         if (pid == ppid)
 183                 ppid = 0;
 184 //      if (isthread)
 185 //              this->flags |= PFLAG_THREAD;
 186
 187         parent = find_proc(ppid);
 188         if (!parent)
 189                 parent = new_proc("?", ppid, 0);
 190
 191         add_child(parent, this);
 192         this->parent = parent;
 193 }
 194
 195 static int tree_equal(const PROC *a, const PROC *b)
 196 {
 197         const CHILD *walk_a, *walk_b;
 198
 199         if (strcmp(a->comm, b->comm) != 0)
 200                 return 0;
 201         if ((option_mask32 /*& OPT_PID*/) && a->pid != b->pid)
 202                 return 0;
 203
 204         for (walk_a = a->children, walk_b = b->children;
 205           walk_a && walk_b;
 206           walk_a = walk_a->next, walk_b = walk_b->next
 207         ) {
 208                 if (!tree_equal(walk_a->child, walk_b->child))
 209                         return 0;
 210         }
 211
 212         return !(walk_a || walk_b);
 213 }
 214
 215 static int out_args(const char *mystr)
 216 {
 217         const char *here;
 218         int strcount = 0;
 219         char tmpstr[5];
 220
 221         for (here = mystr; *here; here++) {
 222                 if (*here == '\\') {
 223                         out_string("\\\\");
 224                         strcount += 2;
 225                 } else if (*here >= ' ' && *here < 0x7f) {
 226                         out_char(*here);
 227                         strcount++;
 228                 } else {
 229                         sprintf(tmpstr, "\\%03o", (unsigned char) *here);
 230                         out_string(tmpstr);
 231                         strcount += 4;
 232                 }
 233         }
 234
 235         return strcount;
 236 }
 237
 238 static void
 239 dump_tree(PROC *current, int level, int rep, int leaf, int last, int closing)
 240 {
 241         CHILD *walk, *next, **scan;
 242         int lvl, i, add, offset, count, comm_len, first;
 243         char tmp[sizeof(int)*3 + 4];
 244
 245         if (!current)
 246                 return;
 247
 248         if (!leaf) {
 249                 for (lvl = 0; lvl < level; lvl++) {
 250                         i = G.width[lvl] + 1;
 251                         while (--i >= 0)
 252                                 out_char(' ');
 253
 254                         if (lvl == level - 1) {
 255                                 if (last) {
 256                                         out_string(last_2);
 257                                 } else {
 258                                         out_string(branch_2);
 259                                 }
 260                         } else {
 261                                 if (G.more[lvl + 1]) {
 262                                         out_string(vert_2);
 263                                 } else {
 264                                         out_string(empty_2);
 265                                 }
 266                         }
 267                 }
 268         }
 269
 270         add = 0;
 271         if (rep > 1) {
 272                 add += sprintf(tmp, "%d*[", rep);
 273                 out_string(tmp);
 274         }
 275         comm_len = out_args(current->comm);
 276         if (option_mask32 /*& OPT_PID*/) {
 277                 comm_len += sprintf(tmp, "(%d)", (int)current->pid);
 278                 out_string(tmp);
 279         }
 280         offset = G.cur_x;
 281
 282         if (!current->children) {
 283                 while (closing--)
 284                         out_char(']');
 285                 out_newline();
 286         }
 287         ensure_buffer_capacity(level);
 288         G.more[level] = !last;
 289
 290         G.width[level] = comm_len + G.cur_x - offset + add;
 291         if (G.cur_x >= G.output_width) {
 292                 //out_string(first_3); - why? it won't print anything
 293                 //out_char('+');
 294                 out_newline();
 295                 return;
 296         }
 297
 298         first = 1;
 299         for (walk = current->children; walk; walk = next) {
 300                 count = 0;
 301                 next = walk->next;
 302                 scan = &walk->next;
 303                 while (*scan) {
 304                         if (!tree_equal(walk->child, (*scan)->child))
 305                                 scan = &(*scan)->next;
 306                         else {
 307                                 if (next == *scan)
 308                                         next = (*scan)->next;
 309                                 count++;
 310                                 *scan = (*scan)->next;
 311                         }
 312                 }
 313                 if (first) {
 314                         out_string(next ? first_3 : single_3);
 315                         first = 0;
 316                 }
 317
 318                 dump_tree(walk->child, level + 1, count + 1,
 319                                 walk == current->children, !next,
 320                                 closing + (count ? 1 : 0));
 321         }
 322 }
 323
 324 static void dump_by_user(PROC *current, uid_t uid)
 325 {
 326         const CHILD *walk;
 327
 328         if (!current)
 329                 return;
 330
 331         if (current->uid == uid) {
 332                 if (G.dumped)
 333                         putchar('\n');
 334                 dump_tree(current, 0, 1, 1, 1, 0);
 335                 G.dumped = 1;
 336                 return;
 337         }
 338         for (walk = current->children; walk; walk = walk->next)
 339                 dump_by_user(walk->child, uid);
 340 }
 341
 342 static void handle_thread(const char *comm, pid_t pid, pid_t ppid, uid_t uid)
 343 {
 344         char threadname[COMM_LEN + 2];
 345         sprintf(threadname, "{%.*s}", COMM_LEN - 2, comm);
 346         add_proc(threadname, pid, ppid, uid/*, 1*/);
 347 }
 348
 349 static void mread_proc(void)
 350 {
 351         procps_status_t *p = NULL;
 352         pid_t parent = 0;
 353         int flags = PSSCAN_COMM | PSSCAN_PID | PSSCAN_PPID | PSSCAN_UIDGID | PSSCAN_TASKS;
 354
 355         while ((p = procps_scan(p, flags)) != NULL) {
 356 #if ENABLE_FEATURE_SHOW_THREADS
 357                 if (p->pid != p->main_thread_pid)
 358                         handle_thread(p->comm, p->pid, parent, p->uid);
 359                 else
 360 #endif
 361                 {
 362                         add_proc(p->comm, p->pid, p->ppid, p->uid/*, 0*/);
 363                         parent = p->pid;
 364                 }
 365         }
 366 }
 367
 368 int pstree_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 369 int pstree_main(int argc UNUSED_PARAM, char **argv)
 370 {
 371         pid_t pid = 1;
 372         long uid = 0;
 373
 374         INIT_G();
 375
 376         get_terminal_width_height(0, &G.output_width, NULL);
 377
 378         opt_complementary = "?1";
 379         getopt32(argv, "p");
 380         argv += optind;
 381
 382         if (argv[0]) {
 383                 if (argv[0][0] >= '0' && argv[0][0] <= '9') {
 384                         pid = xatoi(argv[0]);
 385                 } else {
 386                         uid = xuname2uid(argv[0]);
 387                 }
 388         }
 389
 390         mread_proc();
 391
 392         if (!uid)
 393                 dump_tree(find_proc(pid), 0, 1, 1, 1, 0);
 394         else {
 395                 dump_by_user(find_proc(1), uid);
 396                 if (!G.dumped) {
 397                         bb_error_msg_and_die("no processes found");
 398                 }
 399         }
 400
 401         if (ENABLE_FEATURE_CLEAN_UP) {
 402                 free(G.width);
 403                 free(G.more);
 404         }
 405         return 0;
 406 }