X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2FEDITME;h=1bff9dab26d2898f886cd41d2fb2a432a95717b5;hp=7f7f6b3a44e7c033124513f618251731f085779a;hb=e21a4d0042e48109cef06e48b8a73dd79d7a4330;hpb=10385c155b0e1266c02535b76ab73b32fa83d73f diff --git a/src/src/EDITME b/src/src/EDITME index 7f7f6b3a4..1bff9dab2 100644 --- a/src/src/EDITME +++ b/src/src/EDITME @@ -1,5 +1,3 @@ -# $Cambridge: exim/src/src/EDITME,v 1.26 2010/06/06 02:46:13 pdp Exp $ - ################################################## # The Exim mail transport agent # ################################################## @@ -248,6 +246,27 @@ TRANSPORT_SMTP=yes # SUPPORT_MBX=yes +#------------------------------------------------------------------------------ +# See below for dynamic lookup modules. +# +# If not using package management but using this anyway, then think about how +# you perform upgrades and revert them. You should consider the benefit of +# embedding the Exim version number into LOOKUP_MODULE_DIR, so that you can +# maintain two concurrent sets of modules. +# +# *BEWARE*: ability to modify the files in LOOKUP_MODULE_DIR is equivalent to +# the ability to modify the Exim binary, which is often setuid root! The Exim +# developers only intend this functionality be used by OS software packagers +# and we suggest that such packagings' integrity checks should be paranoid +# about the permissions of the directory and the files within. + +# LOOKUP_MODULE_DIR=/usr/lib/exim/lookups/ + +# To build a module dynamically, you'll need to define CFLAGS_DYNAMIC for +# your platform. Eg: +# CFLAGS_DYNAMIC=-shared -rdynamic +# CFLAGS_DYNAMIC=-shared -rdynamic -fPIC + #------------------------------------------------------------------------------ # These settings determine which file and database lookup methods are included # in the binary. See the manual chapter entitled "File and database lookups" @@ -256,6 +275,27 @@ TRANSPORT_SMTP=yes # LOOKUP_DNSDB does *not* refer to general mail routing using the DNS. It is # for the specialist case of using the DNS as a general database facility (not # common). +# If set to "2" instead of "yes" then the corresponding lookup will be +# built as a module and must be installed into LOOKUP_MODULE_DIR. You need to +# add -export-dynamic -rdynamic to EXTRALIBS. You may also need to add -ldl to +# EXTRALIBS so that dlopen() is available to Exim. You need to define +# LOOKUP_MODULE_DIR above so the exim binary actually loads dynamic lookup +# modules. +# Also, instead of adding all the libraries/includes to LOOKUP_INCLUDE and +# LOOKUP_LIBS, add them to the respective LOOKUP_*_INCLUDE and LOOKUP_*_LIBS +# (where * is the name as given here in this list). That ensures that only +# the dynamic library and not the exim binary will be linked against the +# library. +# NOTE: LDAP cannot be built as a module! +# +# For Redis you need to have hiredis installed on your system +# (https://github.com/redis/hiredis). +# Depending on where it is installed you may have to edit the CFLAGS +# (often += -I/usr/local/include) and LDFLAGS (-lhiredis) lines. + +# If your system has pkg-config then the _INCLUDE/_LIBS setting can be +# handled for you automatically by also defining the _PC variable to reference +# the name of the pkg-config package, if such is available. LOOKUP_DBM=yes LOOKUP_LSEARCH=yes @@ -271,7 +311,9 @@ LOOKUP_DNSDB=yes # LOOKUP_ORACLE=yes # LOOKUP_PASSWD=yes # LOOKUP_PGSQL=yes +# LOOKUP_REDIS=yes # LOOKUP_SQLITE=yes +# LOOKUP_SQLITE_PC=sqlite3 # LOOKUP_WHOSON=yes # These two settings are obsolete; all three lookups are compiled when @@ -300,16 +342,19 @@ LOOKUP_DNSDB=yes #------------------------------------------------------------------------------ -# The PCRE library is required for exim. There is no longer an embedded +# The PCRE library is required for Exim. There is no longer an embedded # version of the PCRE library included with the source code, instead you # must use a system library or build your own copy of PCRE. # In either case you must specify the library link info here. If the # PCRE header files are not in the standard search path you must also # modify the INCLUDE path (above) -# The default setting of PCRE_LIBS should work on the vast majority of -# systems +# +# Use PCRE_CONFIG to query the pcre-config command (first found in $PATH) +# to find the include files and libraries, else use PCRE_LIBS and set INCLUDE +# too if needed. -PCRE_LIBS=-lpcre +PCRE_CONFIG=yes +# PCRE_LIBS=-lpcre #------------------------------------------------------------------------------ @@ -318,7 +363,10 @@ PCRE_LIBS=-lpcre # the command for linking Exim itself, not on any auxiliary programs. You # don't need to set LOOKUP_INCLUDE if the relevant directories are already # specified in INCLUDE. The settings below are just examples; -lpq is for -# PostgreSQL, -lgds is for Interbase, -lsqlite3 is for SQLite. +# PostgreSQL, -lgds is for Interbase, -lsqlite3 is for SQLite, -lhiredis +# is for Redis. +# +# You do not need to use this for any lookup information added via pkg-config. # LOOKUP_INCLUDE=-I /usr/local/ldap/include -I /usr/local/mysql/include -I /usr/local/pgsql/include # LOOKUP_LIBS=-L/usr/local/lib -lldap -llber -lmysqlclient -lpq -lgds -lsqlite3 @@ -344,13 +392,7 @@ EXIM_MONITOR=eximon.bin # WITH_CONTENT_SCAN=yes -# If you want to use the deprecated "demime" condition in the DATA ACL, -# uncomment the line below. Doing so will also explicitly turn on the -# WITH_CONTENT_SCAN option. If possible, use the MIME ACL instead of -# the "demime" condition. - -# WITH_OLD_DEMIME=yes - +#------------------------------------------------------------------------------ # If you're using ClamAV and are backporting fixes to an old version, instead # of staying current (which is the more usual approach) then you may need to # use an older API which uses a STREAM command, now deprecated, instead of @@ -360,8 +402,9 @@ EXIM_MONITOR=eximon.bin # # WITH_OLD_CLAMAV_STREAM=yes + #------------------------------------------------------------------------------ -# By default Exim includes code to support DKIM (DomainKeys Identified +# If built with TLS, Exim includes code to support DKIM (DomainKeys Identified # Mail, RFC4871) signing and verification. Verification of signatures is # turned on by default. See the spec for information on conditionally # disabling it. To disable the inclusion of the entire feature, set @@ -369,12 +412,42 @@ EXIM_MONITOR=eximon.bin # DISABLE_DKIM=yes +#------------------------------------------------------------------------------ +# Uncomment the following line to remove Per-Recipient-Data-Response support. + +# DISABLE_PRDR=yes + +#------------------------------------------------------------------------------ +# Uncomment the following line to remove OCSP stapling support in TLS, +# from Exim. Note it can only be supported when built with +# GnuTLS 3.1.3 or later, or OpenSSL + +# DISABLE_OCSP=yes + +#------------------------------------------------------------------------------ +# By default, Exim has support for checking the AD bit in a DNS response, to +# determine if DNSSEC validation was successful. If your system libraries +# do not support that bit, then set DISABLE_DNSSEC to "yes" +# Note: Enabling EXPERIMENTAL_DANE unconditionally overrides this setting. + +# DISABLE_DNSSEC=yes + +# To disable support for Events set DISABLE_EVENT to "yes" + +# DISABLE_EVENT=yes + #------------------------------------------------------------------------------ # Compiling Exim with experimental features. These are documented in # experimental-spec.txt. "Experimental" means that the way these features are # implemented may still change. Backward compatibility is not guaranteed. +# Uncomment the following line to add support for talking to dccifd. This +# defaults the socket path to /usr/local/dcc/var/dccifd. +# Doing so will also explicitly turn on the WITH_CONTENT_SCAN option. + +# EXPERIMENTAL_DCC=yes + # Uncomment the following lines to add SPF support. You need to have libspf2 # installed on your system (www.libspf2.org). Depending on where it is installed # you may have to edit the CFLAGS and LDFLAGS lines. @@ -392,6 +465,12 @@ EXIM_MONITOR=eximon.bin # CFLAGS += -I/usr/local/include # LDFLAGS += -lsrs_alt +# Uncomment the following line to add DMARC checking capability, implemented +# using libopendmarc libraries. You must have SPF support enabled also. +# EXPERIMENTAL_DMARC=yes +# CFLAGS += -I/usr/local/include +# LDFLAGS += -lopendmarc + # Uncomment the following lines to add Brightmail AntiSpam support. You need # to have the Brightmail client SDK installed. Please check the experimental # documentation for implementation details. You need to edit the CFLAGS and @@ -401,7 +480,23 @@ EXIM_MONITOR=eximon.bin # CFLAGS += -I/opt/brightmail/bsdk-6.0/include # LDFLAGS += -lxml2_single -lbmiclient_single -L/opt/brightmail/bsdk-6.0/lib +# Uncomment the following line to add DANE support +# Note: Enabling this unconditionally overrides DISABLE_DNSSEC +# Note: DANE is only supported when using OpenSSL +# EXPERIMENTAL_DANE=yes + +# Uncomment the following to include extra information in fail DSN message (bounces) +# EXPERIMENTAL_DSN_INFO=yes +# Uncomment the following to add LMDB lookup support +# You need to have LMDB installed on your system (https://github.com/LMDB/lmdb) +# Depending on where it is installed you may have to edit the CFLAGS and LDFLAGS lines. +# EXPERIMENTAL_LMDB=yes +# CFLAGS += -I/usr/local/include +# LDFLAGS += -llmdb + +# Uncomment the following line to add queuefile transport support +# EXPERIMENTAL_QUEUEFILE=yes ############################################################################### # THESE ARE THINGS YOU MIGHT WANT TO SPECIFY # @@ -430,14 +525,13 @@ FIXED_NEVER_USERS=root #------------------------------------------------------------------------------ -# By default, Exim insists that its configuration file be owned either by root -# or by the Exim user. You can specify one additional permitted owner here. +# By default, Exim insists that its configuration file be owned by root. You +# can specify one additional permitted owner here. # CONFIGURE_OWNER= # If the configuration file is group-writeable, Exim insists by default that it -# is owned by root or the Exim user. You can specify one additional permitted -# group owner here. +# is owned by root. You can specify one additional permitted group owner here. # CONFIGURE_GROUP= @@ -459,32 +553,31 @@ FIXED_NEVER_USERS=root #------------------------------------------------------------------------------ # The -C option allows Exim to be run with an alternate runtime configuration -# file. When this is used by root or the Exim user, root privilege is retained -# by the binary (for any other caller, it is dropped). You can restrict the -# location of alternate configurations by defining a prefix below. Any file -# used with -C must then start with this prefix (except that /dev/null is also -# permitted if the caller is root, because that is used in the install script). -# If the prefix specifies a directory that is owned by root, a compromise of -# the Exim account does not permit arbitrary alternate configurations to be -# used. The prefix can be more restrictive than just a directory (the second -# example). +# file. When this is used by root, root privilege is retained by the binary +# (for any other caller including the Exim user, it is dropped). You can +# restrict the location of alternate configurations by defining a prefix below. +# Any file used with -C must then start with this prefix (except that /dev/null +# is also permitted if the caller is root, because that is used in the install +# script). If the prefix specifies a directory that is owned by root, a +# compromise of the Exim account does not permit arbitrary alternate +# configurations to be used. The prefix can be more restrictive than just a +# directory (the second example). # ALT_CONFIG_PREFIX=/some/directory/ # ALT_CONFIG_PREFIX=/some/directory/exim.conf- #------------------------------------------------------------------------------ -# If you uncomment the following line, only root may use the -C or -D options -# without losing root privilege. The -C option specifies an alternate runtime -# configuration file, and the -D option changes macro values in the runtime -# configuration. Uncommenting this line restricts what can be done with these -# options. A call to receive a message (either one-off or via a daemon) cannot -# successfully continue to deliver it, because the re-exec of Exim to regain -# root privilege will fail, owing to the use of -C or -D by the Exim user. -# However, you can still use -C for testing (as root) if you do separate Exim -# calls for receiving a message and subsequently delivering it. +# When a user other than root uses the -C option to override the configuration +# file (including the Exim user when re-executing Exim to regain root +# privileges for local message delivery), this will normally cause Exim to +# drop root privileges. The TRUSTED_CONFIG_LIST option, specifies a file which +# contains a list of trusted configuration filenames, one per line. If the -C +# option is used by the Exim user or by the user specified in the +# CONFIGURE_OWNER setting, to specify a configuration file which is listed in +# the TRUSTED_CONFIG_LIST file, then root privileges are not dropped by Exim. -# ALT_CONFIG_ROOT_ONLY=yes +# TRUSTED_CONFIG_LIST=/usr/exim/trusted_configs #------------------------------------------------------------------------------ @@ -495,6 +588,31 @@ FIXED_NEVER_USERS=root # DISABLE_D_OPTION=yes +#------------------------------------------------------------------------------ +# By contrast, you might be maintaining a system which relies upon the ability +# to override values with -D and assumes that these will be passed through to +# the delivery processes. As of Exim 4.73, this is no longer the case by +# default. Going forward, we strongly recommend that you use a shim Exim +# configuration file owned by root stored under TRUSTED_CONFIG_LIST. +# That shim can set macros before .include'ing your main configuration file. +# +# As a strictly transient measure to ease migration to 4.73, the +# WHITELIST_D_MACROS value definies a colon-separated list of macro-names +# which are permitted to be overridden from the command-line which will be +# honoured by the Exim user. So these are macros that can persist to delivery +# time. +# Examples might be -DTLS or -DSPOOL=/some/dir. The values on the +# command-line are filtered to only permit: [A-Za-z0-9_/.-]* +# +# This option is highly likely to be removed in a future release. It exists +# only to make 4.73 as easy as possible to migrate to. If you use it, we +# encourage you to schedule time to rework your configuration to not depend +# upon it. Most people should not need to use this. +# +# By default, no macros are whitelisted for -D usage. + +# WHITELIST_D_MACROS=TLS:SPOOL + #------------------------------------------------------------------------------ # Exim has support for the AUTH (authentication) extension of the SMTP # protocol, as defined by RFC 2554. If you don't know what SMTP authentication @@ -507,16 +625,25 @@ FIXED_NEVER_USERS=root # AUTH_CRAM_MD5=yes # AUTH_CYRUS_SASL=yes # AUTH_DOVECOT=yes +# AUTH_GSASL=yes +# AUTH_GSASL_PC=libgsasl +# AUTH_HEIMDAL_GSSAPI=yes +# AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi # AUTH_PLAINTEXT=yes # AUTH_SPA=yes +# AUTH_TLS=yes #------------------------------------------------------------------------------ # If you specified AUTH_CYRUS_SASL above, you should ensure that you have the # Cyrus SASL library installed before trying to build Exim, and you probably -# want to uncomment the following line: +# want to uncomment the first line below. +# Similarly for GNU SASL, unless pkg-config is used via AUTH_GSASL_PC. +# Ditto for AUTH_HEIMDAL_GSSAPI(_PC). # AUTH_LIBS=-lsasl2 +# AUTH_LIBS=-lgsasl +# AUTH_LIBS=-lgssapi -lheimntlm -lkrb5 -lhx509 -lcom_err -lhcrypto -lasn1 -lwind -lroken -lcrypt #------------------------------------------------------------------------------ @@ -609,13 +736,27 @@ HEADERS_CHARSET="ISO-8859-1" # This setting is required for any TLS support (either OpenSSL or GnuTLS) # SUPPORT_TLS=yes -# Uncomment this setting if you are using OpenSSL +# Uncomment one of these settings if you are using OpenSSL; pkg-config vs not +# USE_OPENSSL_PC=openssl # TLS_LIBS=-lssl -lcrypto -# Uncomment these settings if you are using GnuTLS +# Uncomment the first and either the second or the third of these if you +# are using GnuTLS. If you have pkg-config, then the second, else the third. # USE_GNUTLS=yes +# USE_GNUTLS_PC=gnutls # TLS_LIBS=-lgnutls -ltasn1 -lgcrypt +# If using GnuTLS older than 2.10 and using pkg-config then note that Exim's +# build process will require libgcrypt-config to exist in your $PATH. A +# version that old is likely to become unsupported by Exim in 2017. + +# The security fix we provide with the gnutls_allow_auto_pkcs11 option +# (4.82 PP/09) introduces a compatibility regression. The symbol is +# not available if GnuTLS is build without p11-kit (--without-p11-kit +# configure option). In this case use AVOID_GNUTLS_PKCS11=yes when +# building Exim. +# AVOID_GNUTLS_PKCS11=yes + # If you are running Exim as a server, note that just building it with TLS # support is not all you need to do. You also need to set up a suitable # certificate, and tell Exim about it by means of the tls_certificate @@ -624,6 +765,11 @@ HEADERS_CHARSET="ISO-8859-1" # if you are running Exim only as a client, building it with TLS support # is all you need to do. +# If you are using pkg-config then you should not need to worry where the +# libraries and headers are installed, as the pkg-config .pc specification +# should include all -L/-I information necessary. If not using pkg-config +# then you might need to specify the locations too. + # Additional libraries and include files are required for both OpenSSL and # GnuTLS. The TLS_LIBS settings above assume that the libraries are installed # with all your other libraries. If they are in a special directory, you may @@ -653,7 +799,7 @@ HEADERS_CHARSET="ISO-8859-1" # with the extension "texinfo" in the doc directory. You may find that the # version number of the texinfo files is different to your Exim version number, # because the main documentation isn't updated as often as the code. For -# example, if you have Exim version 4.43, the source tarball upacks into a +# example, if you have Exim version 4.43, the source tarball unpacks into a # directory called exim-4.43, but the texinfo tarball unpacks into exim-4.40. # In this case, move the contents of exim-4.40/doc into exim-4.43/doc after you # have unpacked them. Then set INFO_DIRECTORY to the location of your info @@ -731,9 +877,15 @@ COMPRESS_SUFFIX=gz # If the exigrep utility is fed compressed log files, it tries to uncompress # them using this command. +# Leave it empty to enforce autodetection at runtime: +# ZCAT_COMMAND= +# +# Omit the path if you want to use your system's PATH: +# ZCAT_COMMAND=zcat +# +# Or specify the full pathname: ZCAT_COMMAND=/usr/bin/zcat - #------------------------------------------------------------------------------ # Compiling in support for embedded Perl: If you want to be able to # use Perl code in Exim's string manipulation language and you have Perl @@ -766,6 +918,36 @@ ZCAT_COMMAND=/usr/bin/zcat # GNU/Linux -ldl is also needed. +#------------------------------------------------------------------------------ +# Proxying. +# +# If you may want to use outbound (client-side) proxying, using Socks5, +# uncomment the line below. + +# SUPPORT_SOCKS=yes + +# If you may want to use inbound (server-side) proxying, using Proxy Protocol, +# uncomment the line below. + +# SUPPORT_PROXY=yes + + +#------------------------------------------------------------------------------ +# Internationalisation. +# +# Uncomment the following to include Internationalisation features. This is the +# SMTPUTF8 ESMTP extension, and associated facilities for handling UTF8 domain +# and localparts, per RFC 3490 (IDNA2003). +# You need to have the IDN library installed. +# If you want IDNA2008 mappings per RFCs 5890, 6530 and 6533, you additionally +# need libidn2 and SUPPORT_I18N_2008. + +# SUPPORT_I18N=yes +# LDFLAGS += -lidn +# SUPPORT_I18N_2008=yes +# LDFLAGS += -lidn -lidn2 + + #------------------------------------------------------------------------------ # Support for authentication via Radius is also available. The Exim support, # which is intended for use in conjunction with the SMTP AUTH facilities, @@ -808,7 +990,7 @@ ZCAT_COMMAND=/usr/bin/zcat # There is no need to install all of SASL on your system. You just need to run # ./configure --with-pwcheck, cd to the pwcheck directory within the sources, # make and make install. You must create the socket directory (default -# /var/pwcheck) and chown it to exim's user and group. Once you have installed +# /var/pwcheck) and chown it to Exim's user and group. Once you have installed # pwcheck, you should arrange for it to be started by root at boot time. # CYRUS_PWCHECK_SOCKET=/var/pwcheck/pwcheck @@ -816,7 +998,7 @@ ZCAT_COMMAND=/usr/bin/zcat #------------------------------------------------------------------------------ # Support for authentication via the Cyrus SASL saslauthd daemon is available. -# The Exim support, which is intented for use in conjunction with the SMTP AUTH +# The Exim support, which is intended for use in conjunction with the SMTP AUTH # facilities, is included only when requested by setting the following # parameter to the location of the saslauthd daemon's socket. # @@ -824,7 +1006,7 @@ ZCAT_COMMAND=/usr/bin/zcat # ./configure --with-saslauthd (and any other options you need, for example, to # select or deselect authentication mechanisms), cd to the saslauthd directory # within the sources, make and make install. You must create the socket -# directory (default /var/state/saslauthd) and chown it to exim's user and +# directory (default /var/state/saslauthd) and chown it to Exim's user and # group. Once you have installed saslauthd, you should arrange for it to be # started by root at boot time. @@ -847,6 +1029,13 @@ ZCAT_COMMAND=/usr/bin/zcat # # but of course there may need to be other things in CFLAGS and EXTRALIBS_EXIM # as well. +# +# To use a name other than exim in the tcpwrappers config file, +# e.g. if you're running multiple daemons with different access lists, +# or multiple MTAs with the same access list, define +# TCP_WRAPPERS_DAEMON_NAME accordingly +# +# TCP_WRAPPERS_DAEMON_NAME="exim" #------------------------------------------------------------------------------ @@ -895,6 +1084,10 @@ SYSTEM_ALIASES_FILE=/etc/aliases # dynamic loading library is not otherwise included. +#------------------------------------------------------------------------------ +# Uncomment this setting to include IPv6 support. + +# HAVE_IPV6=yes ############################################################################### # THINGS YOU ALMOST NEVER NEED TO MENTION # @@ -940,9 +1133,11 @@ SYSTEM_ALIASES_FILE=/etc/aliases # files, and thus be influenced by the value of TMPDIR. For this reason, when # Exim starts, it checks the environment for TMPDIR, and if it finds it is set, # it replaces the value with what is defined here. Commenting this setting -# suppresses the check altogether. +# suppresses the check altogether. Older installations call this macro +# just TMPDIR, but this has side effects at build time. At runtime +# TMPDIR is checked as before. -TMPDIR="/tmp" +EXIM_TMPDIR="/tmp" #------------------------------------------------------------------------------ @@ -974,7 +1169,7 @@ TMPDIR="/tmp" # to handle the different cases. If CONFIGURE_FILE_USE_EUID is defined, then # Exim will first look for a configuration file whose name is that defined # by CONFIGURE_FILE, with the effective uid tacked on the end, separated by -# a period (for eximple, /usr/exim/configure.0). If this file does not exist, +# a period (for example, /usr/exim/configure.0). If this file does not exist, # then the bare configuration file name is tried. In the case when both # CONFIGURE_FILE_USE_EUID and CONFIGURE_FILE_USE_NODE are set, four files # are tried: .., ., ., and . @@ -1110,6 +1305,12 @@ TMPDIR="/tmp" # PERL_LIBS= +#------------------------------------------------------------------------------ +# If you wish to disable valgrind in the binary, define NVALGRIND=1. +# This should not be needed. + +# NVALGRIND=1 + #------------------------------------------------------------------------------ # Identifying the daemon: When an Exim daemon starts up, it writes its pid # (process id) to a file so that it can easily be identified. The path of the @@ -1151,6 +1352,26 @@ TMPDIR="/tmp" # SUPPORT_MOVE_FROZEN_MESSAGES=yes +#------------------------------------------------------------------------------ +# Expanding match_* second parameters: BE CAREFUL IF ENABLING THIS! +# It has proven too easy in practice for administrators to configure security +# problems into their Exim install, by treating match_domain{}{} and friends +# as a form of string comparison, where the second string comes from untrusted +# data. Because these options take lists, which can include lookup;LOOKUPDATA +# style elements, a foe can then cause Exim to, eg, execute an arbitrary MySQL +# query, dropping tables. +# From Exim 4.77 onwards, the second parameter is not expanded; it can still +# be a list literal, or a macro, or a named list reference. There is also +# the new expansion condition "inlisti" which does expand the second parameter, +# but treats it as a list of strings; also, there's "eqi" which is probably +# what is normally wanted. +# +# If you really need to have the old behaviour, know what you are doing and +# will not complain if your system is compromised as a result of doing so, then +# uncomment this option to get the old behaviour back. + +# EXPAND_LISTMATCH_RHS=yes + #------------------------------------------------------------------------------ # Disabling the use of fsync(): DO NOT UNCOMMENT THE FOLLOWING LINE unless you # really, really, really know what you are doing. And even then, think again.