release/src/router/busybox/procps/pwdx.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * pwdx implementation for busybox
   4  *
   5  * Copyright (c) 2004 Nicholas Miell
   6  * ported from procps by Pere Orga <gotrunks@gmail.com> 2011
   7  *
   8  * Licensed under GPLv2, see file LICENSE in this source tree.
   9  */
  10
  11 //config:config PWDX
  12 //config:       bool "pwdx"
  13 //config:       default y
  14 //config:       help
  15 //config:         Report current working directory of a process
  16
  17 //applet:IF_PWDX(APPLET(pwdx, BB_DIR_USR_BIN, BB_SUID_DROP))
  18
  19 //kbuild:lib-$(CONFIG_PWDX) += pwdx.o
  20
  21 //usage:#define pwdx_trivial_usage
  22 //usage:       "PID..."
  23 //usage:#define pwdx_full_usage "\n\n"
  24 //usage:       "Show current directory for PIDs\n"
  25
  26 #include "libbb.h"
  27
  28 int pwdx_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  29 int pwdx_main(int argc UNUSED_PARAM, char **argv)
  30 {
  31         opt_complementary = "-1";
  32         getopt32(argv, "");
  33         argv += optind;
  34
  35         do {
  36                 char buf[sizeof("/proc/%u/cwd") + sizeof(int)*3];
  37                 unsigned pid;
  38                 char *s;
  39                 char *arg = *argv;
  40
  41                 // Allowed on the command line:
  42                 // /proc/NUM
  43                 // NUM
  44                 if (strncmp(arg, "/proc/", 6) == 0)
  45                         arg += 6;
  46
  47                 pid = bb_strtou(arg, NULL, 10);
  48                 if (errno)
  49                         bb_error_msg_and_die("invalid process id: '%s'", arg);
  50
  51                 sprintf(buf, "/proc/%u/cwd", pid);
  52
  53                 s = xmalloc_readlink(buf);
  54                 // "pwdx /proc/1" says "/proc/1: DIR", not "1: DIR"
  55                 printf("%s: %s\n", *argv, s ? s : strerror(errno == ENOENT ? ESRCH : errno));
  56                 free(s);
  57         } while (*++argv);
  58
  59         return EXIT_SUCCESS;
  60 }