src/unlinkd_daemon.cc

   1 /*
   2  * Copyright (C) 1996-2018 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section --    Unlink Daemon */
  10
  11 #define SQUID_HELPER 1
  12
  13 #include "squid.h"
  14
  15 #include <iostream>
  16 #include <cstdio>
  17 #if HAVE_PATHS_H
  18 #include <paths.h>
  19 #endif
  20
  21 /**
  22  \defgroup unlinkd unlinkd
  23  \ingroup ExternalPrograms
  24  \par
  25     The unlink(2) system call can cause a process to block
  26     for a significant amount of time.  Therefore we do not want
  27     to make unlink() calls from Squid.  Instead we pass them
  28     to this external process.
  29  */
  30
  31 /// \ingroup unlinkd
  32 #define UNLINK_BUF_LEN 1024
  33
  34 /**
  35  \ingroup unlinkd
  36  \par This is the unlinkd external process.
  37  *
  38  \par
  39  *    unlinkd receives the full path of any files to be removed
  40  *    from stdin, each on its own line.
  41  *
  42  \par
  43  *    The results for each file are printed to stdout in the order
  44  *    they were received
  45  *
  46  \param argc Ignored.
  47  \param argv Ignored.
  48  \retval ERR An error occured removing the file.
  49  \retval OK  The file has been removed.
  50  */
  51 int
  52 main(int, char *[])
  53 {
  54     std::string sbuf;
  55     close(2);
  56     if (open(_PATH_DEVNULL, O_RDWR) < 0) {
  57         ; // the irony of having to close(2) earlier is that we cannot report this failure.
  58     }
  59     while (getline(std::cin, sbuf)) {
  60         // tailing newline is removed by getline
  61         const int rv = remove(sbuf.c_str());
  62         if (rv < 0)
  63             std::cout << "ERR" << std::endl; // endl flushes
  64         else
  65             std::cout << "OK" << std::endl;
  66     }
  67
  68     return EXIT_SUCCESS;
  69 }
  70