src/unlinkd_daemon.cc

   1 /*
   2  * DEBUG: section --    Unlink Daemon
   3  * AUTHOR: Duane Wessels
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #define SQUID_HELPER 1
  34
  35 #include "squid.h"
  36
  37 #if HAVE_PATHS_H
  38 #include <paths.h>
  39 #endif
  40
  41 /**
  42  \defgroup unlinkd unlinkd
  43  \ingroup ExternalPrograms
  44  \par
  45     The unlink(2) system call can cause a process to block
  46     for a significant amount of time.  Therefore we do not want
  47     to make unlink() calls from Squid.  Instead we pass them
  48     to this external process.
  49  */
  50
  51 /// \ingroup unlinkd
  52 #define UNLINK_BUF_LEN 1024
  53
  54 /**
  55  \ingroup unlinkd
  56  \par This is the unlinkd external process.
  57  *
  58  \par
  59  *    unlinkd receives the full path of any files to be removed
  60  *    from stdin, each on its own line.
  61  *
  62  \par
  63  *    The results for each file are printed to stdout in the order
  64  *    they were received
  65  *
  66  \param argc Ignored.
  67  \param argv Ignored.
  68  \retval ERR An error occured removing the file.
  69  \retval OK  The file has been removed.
  70  */
  71 int
  72 main(int argc, char *argv[])
  73 {
  74     char buf[UNLINK_BUF_LEN];
  75     char *t;
  76     int x;
  77     setbuf(stdin, NULL);
  78     setbuf(stdout, NULL);
  79     close(2);
  80     if (open(_PATH_DEVNULL, O_RDWR) < 0) {
  81         ; // the irony of having to close(2) earlier is that we cannot report this failure.
  82     }
  83
  84     while (fgets(buf, sizeof(buf), stdin)) {
  85         if ((t = strchr(buf, '\n')))
  86             *t = '\0';
  87         x = unlink(buf);
  88         if (x < 0)
  89             printf("ERR\n");
  90         else
  91             printf("OK\n");
  92     }
  93
  94     return 0;
  95 }