commands/find/find.c

   1 /*      $NetBSD: find.c,v 1.25 2007/09/25 04:10:12 lukem Exp $  */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Cimarron D. Taylor of the University of California, Berkeley.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fts.h>
  43 #include <signal.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <stdlib.h>
  47
  48 #include "find.h"
  49
  50 static int ftscompare(const FTSENT * const *, const FTSENT * const *);
  51
  52 static void sig_lock(sigset_t *);
  53 static void sig_unlock(const sigset_t *);
  54
  55 /*
  56  * find_formplan --
  57  *      process the command line and create a "plan" corresponding to the
  58  *      command arguments.
  59  */
  60 PLAN *
  61 find_formplan(char **argv)
  62 {
  63         PLAN *plan, *tail, *new;
  64
  65         /*
  66          * for each argument in the command line, determine what kind of node
  67          * it is, create the appropriate node type and add the new plan node
  68          * to the end of the existing plan.  The resulting plan is a linked
  69          * list of plan nodes.  For example, the string:
  70          *
  71          *      % find . -name foo -newer bar -print
  72          *
  73          * results in the plan:
  74          *
  75          *      [-name foo]--> [-newer bar]--> [-print]
  76          *
  77          * in this diagram, `[-name foo]' represents the plan node generated
  78          * by c_name() with an argument of foo and `-->' represents the
  79          * plan->next pointer.
  80          */
  81         for (plan = tail = NULL; *argv;) {
  82                 if (!(new = find_create(&argv)))
  83                         continue;
  84                 if (plan == NULL)
  85                         tail = plan = new;
  86                 else {
  87                         tail->next = new;
  88                         tail = new;
  89                 }
  90         }
  91
  92         /*
  93          * if the user didn't specify one of -print, -ok, -fprint, -exec, or
  94          * -exit, then -print is assumed so we bracket the current expression
  95          * with parens, if necessary, and add a -print node on the end.
  96          */
  97         if (!isoutput) {
  98                 if (plan == NULL) {
  99                         new = c_print(NULL, 0);
 100                         tail = plan = new;
 101                 } else {
 102                         new = c_openparen(NULL, 0);
 103                         new->next = plan;
 104                         plan = new;
 105                         new = c_closeparen(NULL, 0);
 106                         tail->next = new;
 107                         tail = new;
 108                         new = c_print(NULL, 0);
 109                         tail->next = new;
 110                         tail = new;
 111                 }
 112         }
 113
 114         /*
 115          * the command line has been completely processed into a search plan
 116          * except for the (, ), !, and -o operators.  Rearrange the plan so
 117          * that the portions of the plan which are affected by the operators
 118          * are moved into operator nodes themselves.  For example:
 119          *
 120          *      [!]--> [-name foo]--> [-print]
 121          *
 122          * becomes
 123          *
 124          *      [! [-name foo] ]--> [-print]
 125          *
 126          * and
 127          *
 128          *      [(]--> [-depth]--> [-name foo]--> [)]--> [-print]
 129          *
 130          * becomes
 131          *
 132          *      [expr [-depth]-->[-name foo] ]--> [-print]
 133          *
 134          * operators are handled in order of precedence.
 135          */
 136
 137         plan = paren_squish(plan);              /* ()'s */
 138         plan = not_squish(plan);                /* !'s */
 139         plan = or_squish(plan);                 /* -o's */
 140         return (plan);
 141 }
 142
 143 static int
 144 ftscompare(const FTSENT * const *e1, const FTSENT * const *e2)
 145 {
 146
 147         return (strcoll((*e1)->fts_name, (*e2)->fts_name));
 148 }
 149
 150 static void
 151 sig_lock(sigset_t *s)
 152 {
 153         sigset_t new;
 154
 155         sigemptyset(&new);
 156 #ifdef SIGINFO
 157         sigaddset(&new, SIGINFO); /* block SIGINFO */
 158 #endif
 159         sigprocmask(SIG_BLOCK, &new, s);
 160 }
 161
 162 static void
 163 sig_unlock(const sigset_t *s)
 164 {
 165
 166         sigprocmask(SIG_SETMASK, s, NULL);
 167 }
 168
 169 FTS *tree;                      /* pointer to top of FTS hierarchy */
 170 FTSENT *g_entry;                /* shared with SIGINFO handler */
 171
 172 /*
 173  * find_execute --
 174  *      take a search plan and an array of search paths and executes the plan
 175  *      over all FTSENT's returned for the given search paths.
 176  */
 177 int
 178 find_execute(PLAN *plan, char **paths)
 179 {
 180         PLAN *p;
 181         int r, rval, cval;
 182         sigset_t s;
 183
 184         cval = 1;
 185
 186         if (!(tree = fts_open(paths, ftsoptions, issort ? ftscompare : NULL)))
 187                 err(1, "ftsopen");
 188
 189         sig_lock(&s);
 190         for (rval = 0; cval && (g_entry = fts_read(tree)) != NULL; sig_lock(&s)) {
 191                 sig_unlock(&s);
 192                 switch (g_entry->fts_info) {
 193                 case FTS_D:
 194                         if (isdepth)
 195                                 continue;
 196                         break;
 197                 case FTS_DP:
 198                         if (!isdepth)
 199                                 continue;
 200                         break;
 201                 case FTS_DNR:
 202                 case FTS_ERR:
 203                 case FTS_NS:
 204                         (void)fflush(stdout);
 205                         warnx("%s: %s",
 206                             g_entry->fts_path, strerror(g_entry->fts_errno));
 207                         rval = 1;
 208                         continue;
 209                 }
 210 #define BADCH   " \t\n\\'\""
 211                 if (isxargs && strpbrk(g_entry->fts_path, BADCH)) {
 212                         (void)fflush(stdout);
 213                         warnx("%s: illegal path", g_entry->fts_path);
 214                         rval = 1;
 215                         continue;
 216                 }
 217
 218                 /*
 219                  * Call all the functions in the execution plan until one is
 220                  * false or all have been executed.  This is where we do all
 221                  * the work specified by the user on the command line.
 222                  */
 223                 for (p = plan; p && (p->eval)(p, g_entry); p = p->next)
 224                         if (p->type == N_EXIT) {
 225                                 rval = p->exit_val;
 226                                 cval = 0;
 227                         }
 228         }
 229
 230         sig_unlock(&s);
 231         if (errno)
 232                 err(1, "fts_read");
 233         (void)fts_close(tree);
 234
 235         /*
 236          * Cleanup any plans with leftover state.
 237          * Keep the last non-zero return value.
 238          */
 239         if ((r = find_traverse(plan, plan_cleanup, NULL)) != 0)
 240                 rval = r;
 241
 242         return (rval);
 243 }
 244
 245 /*
 246  * find_traverse --
 247  *      traverse the plan tree and execute func() on all plans.  This
 248  *      does not evaluate each plan's eval() function; it is intended
 249  *      for operations that must run on all plans, such as state
 250  *      cleanup.
 251  *
 252  *      If any func() returns non-zero, then so will find_traverse().
 253  */
 254 int
 255 find_traverse(plan, func, arg)
 256         PLAN *plan;
 257         int (*func)(PLAN *, void *);
 258         void *arg;
 259 {
 260         PLAN *p;
 261         int r, rval;
 262
 263         rval = 0;
 264         for (p = plan; p; p = p->next) {
 265                 if ((r = func(p, arg)) != 0)
 266                         rval = r;
 267                 if (p->type == N_EXPR || p->type == N_OR) {
 268                         if (p->p_data[0])
 269                                 if ((r = find_traverse(p->p_data[0],
 270                                             func, arg)) != 0)
 271                                         rval = r;
 272                         if (p->p_data[1])
 273                                 if ((r = find_traverse(p->p_data[1],
 274                                             func, arg)) != 0)
 275                                         rval = r;
 276                 }
 277         }
 278         return rval;
 279 }