src/unlinkd_daemon.cc

   1 /*
   2  * Copyright (C) 1996-2014 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 #if HAVE_PATHS_H
  16 #include <paths.h>
  17 #endif
  18
  19 /**
  20  \defgroup unlinkd unlinkd
  21  \ingroup ExternalPrograms
  22  \par
  23     The unlink(2) system call can cause a process to block
  24     for a significant amount of time.  Therefore we do not want
  25     to make unlink() calls from Squid.  Instead we pass them
  26     to this external process.
  27  */
  28
  29 /// \ingroup unlinkd
  30 #define UNLINK_BUF_LEN 1024
  31
  32 /**
  33  \ingroup unlinkd
  34  \par This is the unlinkd external process.
  35  *
  36  \par
  37  *    unlinkd receives the full path of any files to be removed
  38  *    from stdin, each on its own line.
  39  *
  40  \par
  41  *    The results for each file are printed to stdout in the order
  42  *    they were received
  43  *
  44  \param argc Ignored.
  45  \param argv Ignored.
  46  \retval ERR An error occured removing the file.
  47  \retval OK  The file has been removed.
  48  */
  49 int
  50 main(int argc, char *argv[])
  51 {
  52     char buf[UNLINK_BUF_LEN];
  53     char *t;
  54     int x;
  55     setbuf(stdin, NULL);
  56     setbuf(stdout, NULL);
  57     close(2);
  58     if (open(_PATH_DEVNULL, O_RDWR) < 0) {
  59         ; // the irony of having to close(2) earlier is that we cannot report this failure.
  60     }
  61
  62     while (fgets(buf, sizeof(buf), stdin)) {
  63         if ((t = strchr(buf, '\n')))
  64             *t = '\0';
  65         x = unlink(buf);
  66         if (x < 0)
  67             printf("ERR\n");
  68         else
  69             printf("OK\n");
  70     }
  71
  72     return 0;
  73 }