RPM(8) Red Hat Linux RPM(8)

NAME rpm - RPM Package Manager

SYNOPSIS QUERYING AND VERIFYING PACKAGES: rpm {-q|--query} [select-options] [query-options]

rpm {-V|--verify} [select-options] [verify-options]

rpm --import PUBKEY ...

rpm {-K|--checksig} [--nosignature] [--nodigest] PACKAGE_FILE ...

INSTALLING, UPGRADING, AND REMOVING PACKAGES: rpm {-i|--install} [install-options] PACKAGE_FILE ...

rpm {-U|--upgrade} [install-options] PACKAGE_FILE ...

rpm {-F|--freshen} [install-options] PACKAGE_FILE ...

rpm {-e|--erase} [--allmatches] [--nodeps] [--noscripts] [--notriggers] [--repackage] [--test] PACKAGE_NAME ...

MISCELLANEOUS: rpm {--initdb|--rebuilddb}

rpm {--addsign|--resign} PACKAGE_FILE ...

rpm {--querytags|--showrc}

rpm {--setperms|--setugids} PACKAGE_NAME ...

select-options [PACKAGE_NAME] [-a,--all] [-f,--file FILE] [-g,--group GROUP] {-p,--package PACKAGE_FILE] [--fileid MD5] [--hdrid SHA1] [--pkgid MD5] [--tid TID] [--querybynumber HDRNUM] [--triggeredby PACKAGE_NAME] [--whatprovides CAPABILITY] [--whatrequires CAPABILITY]

query-options [--changelog] [-c,--configfiles] [-d,--docfiles] [--dump] [--filesbypkg] [-i,--info] [--last] [-l,--list] [--provides] [--qf,--queryformat QUERYFMT] [-R,--requires] [--scripts] [-s,--state] [--triggers,--triggerscripts]

verify-options [--nodeps] [--nofiles] [--noscripts] [--nodigest] [--nosignature] [--nolinkto] [--nomd5] [--nosize] [--nouser] [--nogroup] [--nomtime] [--nomode] [--nordev]

install-options [--aid] [--allfiles] [--badreloc] [--excludepath OLDPATH] [--excludedocs] [--force] [-h,--hash] [--ignoresize] [--ignorearch] [--ignoreos] [--includedocs] [--justdb] [--nodeps] [--nodigest] [--nosignature] [--nosuggest] [--noorder] [--noscripts] [--notriggers] [--oldpackage] [--percent] [--prefix NEWPATH] [--relocate OLDPATH=NEWPATH] [--repackage] [--replacefiles] [--replacepkgs] [--test]

DESCRIPTION rpm is a powerful Package Manager, which can be used to build, install, query, verify, update, and erase individual software packages. A pack- age consists of an archive of files and meta-data used to install and erase the archive files. The meta-data includes helper scripts, file attributes, and descriptive information about the package. Packages come in two varieties: binary packages, used to encapsulate software to be installed, and source packages, containing the source code and recipe necessary to produce binary packages.

One of the following basic modes must be selected: Query, Verify, Sig- nature Check, Install/Upgrade/Freshen, Uninstall, Initialize Database, Rebuild Database, Resign, Add Signature, Set Owners/Groups, Show Query- tags, and Show Configuration.

GENERAL OPTIONS These options can be used in all the different modes.

-?, --help Print a longer usage message then normal.

--version Print a single line containing the version number of rpm being used.

--quiet Print as little as possible - normally only error messages will be displayed.

-v Print verbose information - normally routine progress messages will be displayed.

-vv Print lots of ugly debugging information.

--rcfile FILELIST Each of the files in the colon separated FILELIST is read sequentially by rpm for configuration information. Only the first file in the list must exist, and tildes will be expanded to the value of $HOME. The default FILELIST is /usr/lib/rpm/rpmrc:/usr/lib/rpm/red- hat/rpmrc:/etc/rpmrc:~/.rpmrc.

--pipe CMD Pipes the output of rpm to the command CMD.

--dbpath DIRECTORY Use the database in DIRECTORY rather than the default path /var/lib/rpm

--root DIRECTORY Use the file system tree rooted at DIRECTORY for all operations. Note that this means the database within DIRECTORY will be used for dependency checks and any scriptlet(s) (e.g. %post if installing, or %prep if building, a package) will be run after a chroot(2) to DIRECTORY.

-D, --defineMACRO EXPR Defines MACRO with value EXPR.

-E, --evalEXPR Prints macro expansion of EXPR.

INSTALL AND UPGRADE OPTIONS The general form of an rpm install command is

rpm {-i|--install} [install-options] PACKAGE_FILE ...

This installs a new package.

The general form of an rpm upgrade command is

rpm {-U|--upgrade} [install-options] PACKAGE_FILE ...

This upgrades or installs the package currently installed to a newer version. This is the same as install, except all other version(s) of the package are removed after the new package is installed.

rpm {-F|--freshen} [install-options] PACKAGE_FILE ...

This will upgrade packages, but only if an earlier version currently exists. The PACKAGE_FILE may be specified as an ftp or http URL, in which case the package will be downloaded before being installed. See FTP/HTTP OPTIONS for information on rpms internal ftp and http client support.

--aid Add suggested packages to the transaction set when needed.

--allfiles Installs or upgrades all the missingok files in the package, regardless if they exist.

--badreloc Used with --relocate, permit relocations on all file paths, not just those OLDPATHs included in the binary package relocation hint(s).

--excludepath OLDPATH Dont install files whose name begins with OLDPATH.

--excludedocs Don t install any files which are marked as documentation (which includes man pages and texinfo documents).

--force Same as using --replacepkgs, --replacefiles, and --oldpackage.

-h, --hash Print 50 hash marks as the package archive is unpacked. Use with -v|--verbose for a nicer display.

--ignoresize Dont check mount file systems for sufficient disk space before installing this package.

--ignorearch Allow installation or upgrading even if the architectures of the binary package and host dont match.

--ignoreos Allow installation or upgrading even if the operating systems of the binary package and host dont match.

--includedocs Install documentation files. This is the default behavior.

--justdb Update only the database, not the filesystem.

--nodigest Dont verify package or header digests when reading.

--nosignature Don t verify package or header signatures when reading.

--nodeps Dont do a dependency check before installing or upgrading a package.

--nosuggest Don t suggest package(s) that provide a missing dependency.

--noorder Dont reorder the packages for an install. The list of packages would normally be reordered to satisfy dependencies.

--noscripts

--nopre

--nopost

--nopreun

--nopostun Dont execute the scriptlet of the same name. The --noscripts option is equivalent to

--nopre --nopost --nopreun --nopostun

and turns off the execution of the corresponding %pre, %post, %preun, and %postun scriptlet(s).

--notriggers

--notriggerin

--notriggerun

--notriggerpostun Dont execute any trigger scriptlet of the named type. The --notriggers option is equivalent to

--notriggerin --notriggerun --notriggerpostun

and turns off execution of the corresponding %triggerin, %trig- gerun, and %triggerpostun scriptlet(s).

--oldpackage Allow an upgrade to replace a newer package with an older one.

--percent Print percentages as files are unpacked from the package archive. This is intended to make rpm easy to run from other tools.

--prefix NEWPATH For relocatable binary packages, translate all file paths that start with the installation prefix in the package relocation hint(s) to NEWPATH.

--relocate OLDPATH=NEWPATH For relocatable binary packages, translate all file paths that start with OLDPATH in the package relocation hint(s) to NEWPATH. This option can be used repeatedly if several OLDPATHs in the package are to be relocated.

--repackage Re-package the files before erasing. The previously installed package will be named according to the macro %_repack- age_name_fmt and will be created in the directory named by the macro %_repackage_dir (default value is /var/spool/repackage).

--replacefiles Install the packages even if they replace files from other, already installed, packages.

--replacepkgs Install the packages even if some of them are already installed on this system.

--test Do not install the package, simply check for and report poten- tial conflicts.

ERASE OPTIONS The general form of an rpm erase command is

rpm {-e|--erase} [--allmatches] [--nodeps] [--noscripts] [--notriggers] [--repackage] [--test] PACKAGE_NAME ...

The following options may also be used:

--allmatches Remove all versions of the package which match PACKAGE_NAME. Normally an error is issued if PACKAGE_NAME matches multiple packages.

--nodeps Dont check dependencies before uninstalling the packages.

--noscripts

--nopreun

--nopostun Don t execute the scriptlet of the same name. The --noscripts option during package erase is equivalent to

--nopreun --nopostun

and turns off the execution of the corresponding %preun, and %postun scriptlet(s).

--notriggers

--notriggerun

--notriggerpostun Don t execute any trigger scriptlet of the named type. The --notriggers option is equivalent to

--notriggerun --notriggerpostun

and turns off execution of the corresponding %triggerun, and %triggerpostun scriptlet(s).

--repackage Re-package the files before erasing. The previously installed package will be named according to the macro %_repack- age_name_fmt and will be created in the directory named by the macro %_repackage_dir (default value is /var/spool/repackage).

--test Dont really uninstall anything, just go through the motions. Useful in conjunction with the -vv option for debugging.

QUERY OPTIONS The general form of an rpm query command is

rpm {-q|--query} [select-options] [query-options]

You may specify the format that package information should be printed in. To do this, you use the

--qf|--queryformat QUERYFMT

option, followed by the QUERYFMT format string. Query formats are mod- ified versions of the standard printf(3) formatting. The format is made up of static strings (which may include standard C character escapes for newlines, tabs, and other special characters) and printf(3) type formatters. As rpm already knows the type to print, the type specifier must be omitted however, and replaced by the name of the header tag to be printed, enclosed by {} characters. Tag names are case insensitive, and the leading RPMTAG_ portion of the tag name may be omitted as well.

Alternate output formats may be requested by following the tag with :typetag. Currently, the following types are supported:

:armor Wrap a public key in ASCII armor.

:base64 Encode binary data using base64.

:date Use strftime(3) "%c" format.

:day Use strftime(3) "%a %b %d %Y" format.

:depflags Format dependency flags.

:fflags Format file flags.

:hex Format in hexadecimal.

:octal Format in octal.

:perms Format file permissions.

:shescape Escape single quotes for use in a script.

:triggertype Display trigger suffix.

For example, to print only the names of the packages queried, you could use %{NAME} as the format string. To print the packages name and dis- tribution information in two columns, you could use %-30{NAME}%{DISTRI- BUTION}. rpm will print a list of all of the tags it knows about when it is invoked with the --querytags argument.

There are two subsets of options for querying: package selection, and information selection.

PACKAGE SELECTION OPTIONS: PACKAGE_NAME Query installed package named PACKAGE_NAME.

-a, --all Query all installed packages.

-f, --file FILE Query package owning FILE.

--fileid MD5 Query package that contains a given file identifier, i.e. the MD5 digest of the file contents.

-g, --group GROUP Query packages with the group of GROUP.

--hdrid SHA1 Query package that contains a given header identifier, i.e. the SHA1 digest of the immutable header region.

-p, --package PACKAGE_FILE Query an (uninstalled) package PACKAGE_FILE. The PACKAGE_FILE may be specified as an ftp or http style URL, in which case the package header will be downloaded and queried. See FTP/HTTP OPTIONS for information on rpms internal ftp and http client support. The PACKAGE_FILE argument(s), if not a binary package, will be interpreted as an ASCII package manifest. Comments are permitted, starting with a #, and each line of a package mani- fest file may include white space separated glob expressions, including URLs with remote glob expressions, that will be expanded to paths that are substituted in place of the package manifest as additional PACKAGE_FILE arguments to the query.

--pkgid MD5 Query package that contains a given package identifier, i.e. the MD5 digest of the combined header and payload contents.

--querybynumber HDRNUM Query the HDRNUMth database entry directly; this is useful only for debugging.

--specfile SPECFILE Parse and query SPECFILE as if it were a package. Although not all the information (e.g. file lists) is available, this type of query permits rpm to be used to extract information from spec files without having to write a specfile parser.

--tid TID Query package(s) that have a given TID transaction identifier. A unix time stamp is currently used as a transaction identifier. All package(s) installed or erased within a single transaction have a common identifier.

--triggeredby PACKAGE_NAME Query packages that are triggered by package(s) PACKAGE_NAME.

--whatprovides CAPABILITY Query all packages that provide the CAPABILITY capability.

--whatrequires CAPABILITY Query all packages that requires CAPABILITY for proper function- ing.

PACKAGE QUERY OPTIONS: --changelog Display change information for the package.

-c, --configfiles List only configuration files (implies -l).

-d, --docfiles List only documentation files (implies -l).

--dump Dump file information as follows (implies -l):

path size mtime md5sum mode owner group isconfig isdoc rdev symlink

--filesbypkg List all the files in each selected package.

-i, --info Display package information, including name, version, and description. This uses the --queryformat if one was specified.

--last Orders the package listing by install time such that the latest packages are at the top.

-l, --list List files in package.

--provides List capabilities this package provides.

-R, --requires List packages on which this package depends.

--scripts List the package specific scriptlet(s) that are used as part of the installation and uninstallation processes.

-s, --state Display the states of files in the package (implies -l). The state of each file is one of normal, not installed, or replaced.

--triggers, --triggerscripts Display the trigger scripts, if any, which are contained in the package.

VERIFY OPTIONS The general form of an rpm verify command is

rpm {-V|--verify} [select-options] [verify-options]

Verifying a package compares information about the installed files in the package with information about the files taken from the package metadata stored in the rpm database. Among other things, verifying compares the size, MD5 sum, permissions, type, owner and group of each file. Any discrepancies are displayed. Files that were not installed from the package, for example, documentation files excluded on instal- lation using the "--excludedocs" option, will be silently ignored.

The package selection options are the same as for package querying (including package manifest files as arguments). Other options unique to verify mode are:

--nodeps Dont verify dependencies of packages.

--nodigest Dont verify package or header digests when reading.

--nofiles Dont verify any attributes of package files.

--noscripts Don t execute the %verifyscript scriptlet (if any).

--nosignature Dont verify package or header signatures when reading.

--nolinkto

--nomd5

--nosize

--nouser

--nogroup

--nomtime

--nomode

--nordev Dont verify the corresponding file attribute.

The format of the output is a string of 8 characters, a possible attribute marker:

c %config configuration file. d %doc documentation file. g %ghost file (i.e. the file contents are not included in the package payload). l %license license file. r %readme readme file.

from the package header, followed by the file name. Each of the 8 characters denotes the result of a comparison of attribute(s) of the file to the value of those attribute(s) recorded in the database. A single "." (period) means the test passed, while a single "?" (question mark) indicates the test could not be performed (e.g. file permissions prevent reading). Otherwise, the (mnemonically emBoldened) character denotes failure of the corresponding --verify test:

S file Size differs M Mode differs (includes permissions and file type) 5 MD5 sum differs D Device major/minor number mismatch L readLink(2) path mismatch U User ownership differs G Group ownership differs T mTime differs

DIGITAL SIGNATURE AND DIGEST VERIFICATION The general forms of rpm digital signature commands are

rpm --import PUBKEY ...

rpm {--checksig} [--nosignature] [--nodigest] PACKAGE_FILE ...

The --checksig option checks all the digests and signatures contained in PACKAGE_FILE to ensure the integrity and origin of the package. Note that signatures are now verified whenever a package is read, and --checksig is useful to verify all of the digests and signatures asso- ciated with a package.

Digital signatures cannot be verified without a public key. An ASCII armored public key can be added to the rpm database using --import. An imported public key is carried in a header, and key ring management is performed exactly like package management. For example, all currently imported public keys can be displayed by:

rpm -qa gpg-pubkey*

Details about a specific public key, when imported, can be displayed by querying. Heres information about the Red Hat GPG/DSA key:

rpm -qi gpg-pubkey-db42a60e

Finally, public keys can be erased after importing just like packages. Heres how to remove the Red Hat GPG/DSA key

rpm -e gpg-pubkey-db42a60e

SIGNING A PACKAGE rpm --addsign|--resign PACKAGE_FILE ...

Both of the --addsign and --resign options generate and insert new sig- natures for each package PACKAGE_FILE given, replacing any existing signatures. There are two options for historical reasons, there is no difference in behavior currently.

USING GPG TO SIGN PACKAGES In order to sign packages using GPG, rpm must be configured to run GPG and be able to find a key ring with the appropriate keys. By default, rpm uses the same conventions as GPG to find key rings, namely the $GNUPGHOME environment variable. If your key rings are not located where GPG expects them to be, you will need to configure the macro %_gpg_path to be the location of the GPG key rings to use.

For compatibility with older versions of GPG, PGP, and rpm, only V3 OpenPGP signature packets should be configured. Either DSA or RSA ver- ification algorithms can be used, but DSA is preferred.

If you want to be able to sign packages you create yourself, you also need to create your own public and secret key pair (see the GPG man- ual). You will also need to configure the rpm macros

%_signature The signature type. Right now only gpg and pgp are supported.

%_gpg_name The name of the "user" whose key you wish to use to sign your packages.

For example, to be able to use GPG to sign packages as the user "John Doe <jdoe@foo.com>" from the key rings located in /etc/rpm/.gpg using the executable /usr/bin/gpg you would include

%_signature gpg %_gpg_path /etc/rpm/.gpg %_gpg_name John Doe <jdoe@foo.com> %_gpgbin /usr/bin/gpg

in a macro configuration file. Use /etc/rpm/macros for per-system con- figuration and ~/.rpmmacros for per-user configuration.

REBUILD DATABASE OPTIONS The general form of an rpm rebuild database command is

rpm {--initdb|--rebuilddb} [-v] [--dbpath DIRECTORY] [--root DIRECTORY]

Use --initdb to create a new database if one doesnt already exist (existing database is not overwritten), use --rebuilddb to rebuild the database indices from the installed package headers.

SHOWRC The command

rpm --showrc

shows the values rpm will use for all of the options are currently set in rpmrc and macros configuration file(s).

FTP/HTTP OPTIONS rpm can act as an FTP and/or HTTP client so that packages can be queried or installed from the internet. Package files for install, upgrade, and query operations may be specified as an ftp or http style URL:

ftp://USER:PASSWORD@HOST:PORT/path/to/package.rpm

If the :PASSWORD portion is omitted, the password will be prompted for (once per user/hostname pair). If both the user and password are omit- ted, anonymous ftp is used. In all cases, passive (PASV) ftp transfers are performed.

rpm allows the following options to be used with ftp URLs:

--ftpproxy HOST The host HOST will be used as a proxy server for all ftp trans- fers, which allows users to ftp through firewall machines which use proxy systems. This option may also be specified by config- uring the macro %_ftpproxy.

--ftpport PORT The TCP PORT number to use for the ftp connection on the proxy ftp server instead of the default port. This option may also be specified by configuring the macro %_ftpport.

rpm allows the following options to be used with http URLs:

--httpproxy HOST The host HOST will be used as a proxy server for all http trans- fers. This option may also be specified by configuring the macro %_httpproxy.

--httpport PORT The TCP PORT number to use for the http connection on the proxy http server instead of the default port. This option may also be specified by configuring the macro %_httpport.

LEGACY ISSUES Executing rpmbuild The build modes of rpm are now resident in the /usr/bin/rpmbuild exe- cutable. Although legacy compatibility provided by the popt aliases below has been adequate, the compatibility is not perfect; hence build mode compatibility through popt aliases is being removed from rpm. Install the package containing rpmbuild (usually rpm-build) and see rpmbuild(8) for documentation of all the rpm build modes previously documented here in rpm(8).

Add the following lines to /etc/popt if you wish to continue invoking rpmbuild from the rpm command line:

rpm exec --bp rpmb -bp rpm exec --bc rpmb -bc rpm exec --bi rpmb -bi rpm exec --bl rpmb -bl rpm exec --ba rpmb -ba rpm exec --bb rpmb -bb rpm exec --bs rpmb -bs rpm exec --tp rpmb -tp rpm exec --tc rpmb -tc rpm exec --ti rpmb -ti rpm exec --tl rpmb -tl rpm exec --ta rpmb -ta rpm exec --tb rpmb -tb rpm exec --ts rpmb -ts rpm exec --rebuild rpmb --rebuild rpm exec --recompile rpmb --recompile rpm exec --clean rpmb --clean rpm exec --rmsource rpmb --rmsource rpm exec --rmspec rpmb --rmspec rpm exec --target rpmb --target rpm exec --short-circuit rpmb --short-circuit

FILES rpmrc Configuration /usr/lib/rpm/rpmrc /usr/lib/rpm/redhat/rpmrc /etc/rpmrc ~/.rpmrc

Macro Configuration /usr/lib/rpm/macros /usr/lib/rpm/redhat/macros /etc/rpm/macros ~/.rpmmacros

Database /var/lib/rpm/Basenames /var/lib/rpm/Conflictname /var/lib/rpm/Dirnames /var/lib/rpm/Filemd5s /var/lib/rpm/Group /var/lib/rpm/Installtid /var/lib/rpm/Name /var/lib/rpm/Packages /var/lib/rpm/Providename /var/lib/rpm/Provideversion /var/lib/rpm/Pubkeys /var/lib/rpm/Removed /var/lib/rpm/Requirename /var/lib/rpm/Requireversion /var/lib/rpm/Sha1header /var/lib/rpm/Sigmd5 /var/lib/rpm/Triggername

Temporary /var/tmp/rpm*

SEE ALSO popt(3), rpm2cpio(8), rpmbuild(8),

rpm --help - as rpm supports customizing the options via popt aliases its impossible to guarantee that whats described in the manual matches whats available.

http://www.rpm.org/ <URL:http://www.rpm.org/>

AUTHORS Marc Ewing <marc@redhat.com> Jeff Johnson <jbj@redhat.com> Erik Troan <ewt@redhat.com>

Red Hat, Inc. 09 June 2002 RPM(8) DISTCACHE(8) distcache DISTCACHE(8)

NAME distcache - Distributed session caching

DESCRIPTION The distcache architecture provides a protocol and set of accompanying tools to allow applications, and indeed machines, to share session state between them by way of a network service.

The primary use of distcache right now is SSL/TLS session caching. This allows SSL/TLS servers (eg. a secure Apache web server providing HTTPS support) to use a centralised session cache, i.e any server may resume SSL/TLS sessions negotiated by any other server on the network. The advantages to this approach include increased freedom of mechanisms for load-balancing.

Existing SSL/TLS load-balancing solutions

Many load-balancers attempt to route incoming connections to servers based on remembering the last mapping from the same source network address. Others, called "SSL sticky" load-balancers, attempt to parse SSL/TLS session ids from handshake messages and so map future session- resume attempts. Both methods have serious weaknesses - the former is generally confused by any form of network address translation (eg. when clients are behind masquerading gateways), and the latter is confused by any SSL/TLS renegotiations. Moreover both are stateful and a poten- tial bottleneck, because there is no obvious way to scale the architec- ture to multiple load-balancers.

Arbitrary SSL/TLS load-balancing with distcache

There is no need nor motivation to route incoming connections to "the same server" to improve the chances for SSL/TLS session resumption, and indeed doing so defeats the point of load-balancing (which is to bal- ance according load or availability). The use of distcache is to ensure that all servers share the same "cache" and so can respond to SSL/TLS session resume requests irrespective of where the previous SSL/TLS con- nection from the same client was mapped to.

It ait just for SSL/TLS ...

Future versions of distcache will expand on the protocol and should provide for a variety of "shared-state" uses besides SSL/TLS session caching. The possibilities include application state caching, network- based shared virtual memory, etc.

TOOLS dc_server Runs a cache server listening on a configurable network address. See dc_server(1).

dc_client Runs a local client proxy. From the point of view of applications this behaves like dc_server, but manages multiplexing application requests to/from a cache server over a single persistent connec- tion. See dc_client(1).

dc_test Sends a (configurable) barrage of session caching requests to a given network address using the distcache protocol. Useful for testing correctness of an installation as well as benchmarking. Can be used directly against an instance of dc_server or against a dc_client proxy. See dc_test(1).

dc_snoop A transparent proxy tool supporting the distcache protocol that can be used to monitor cache operation requests and responses between any two end-points (eg. between an application and dc_client, or between dc_client and dc_server). See dc_snoop(1).

APIS The comments below provide a short summary of the APIs available in distcache. To view more details, consult the section 2 man pages these summaries refer to. If you are using a packaged version of distcache, you may need to ensure that a corresponding "devel" package is installed as the libraries, headers, and API documentation is often packaged independantly of the user tools.

libnal

This is the underlying Network Abstraction Library (hence "NAL") used by the distcache libraries and tools. libnal uses non-blocking sockets, with an addressing abstraction that allows tools to transparently work over unix domain sockets or TCP/IPv4 sockets by a change of address text. For this reason, all the distcache tools can have their "-listen" and "-connect" switches set to work over either kind of transport.

libnal defines various object types;

NAL_ADDRESS (see NAL_ADDRESS_new(2)) The addressing abstraction converts to and from text representa- tions, indicates whether given addresses are valid for listening on, connecting to, or both.

NAL_CONNECTION (see NAL_CONNECTION_new(2)) This encapsulates a network connection that can be used for sending and receiving arbitrary binary data.

NAL_LISTENER (see NAL_LISTENER_new(2)) This encapsulates a listening socket that can be used to accept incoming connection requests on a configured address, creating a NAL_CONNECTION wrapper for each accepted connection.

NAL_SELECTOR (see NAL_SELECTOR_new(2)) This provides an object that can be prepared with various NAL_LIS- TENER and NAL_CONNECTION objects, and then can block waiting for network activity up to some configurable limit of time. This is the basis of non-blocking I/O and is an encapsulation of the tradi- tional select(2) function.

NAL_BUFFER (see NAL_BUFFER_new(2)) This abstraction implements a FIFO data array and is used primarily for representing the read and send parts of a NAL_CONNECTION object.

There are also some helper functions to assist in serialising data, particularly with respect to putting integral data into network byte order (allowing interoperability between platforms with differing byte-order). These functions are documented in NAL_decode_uint32(2).

libdistcache

There are two APIs implemented by the libdistcache library;

distcache/dc_plug.h This header provides the DC_PLUG abstraction. This encapsulates a connection and implements the distcache protocol and various func- tions for manipulating the reading and writing of distcache mes- sages (requests or responses). This abstraction can support client and server implementations of the distcache protocol and supports asynchronous behaviour by interacting with libnal s NAL_SELECTOR type. For more information, see DC_PLUG_new(2).

distcache/dc_client.h This header declares a higher-level (and much simpler) API than dc_plug.h, and is useful in applications that want API functions that do cache operations. The API is blocking, and provides simplistic add, remove, and get functions that only return once the full request/response cycle is complete or an error has occured. This is the API used to add distcache support to applications like Apache, stunnel, etc. For more information, see DC_CTX_new(2).

libdistcacheserver

This header declares an API for implementing a session cache supporting the distcache protocol. It is primarily intended for environments that wish to implement an alternative method for session storage. As with elements of libdistcache, this API is likely to be undergoing some important restructuring and enhancements. Please consider subscribing to the distcache mail list and/or monitoring CVS, this gives you an opportunity to influence ongoing development and be less surprised at changes the turn up in future versions. For more information, see DC_SERVER_new(2).

LICENSE The distcache toolkit, including the libnal network abstraction library that comes bundled with it, is distributed under the LGPL license ("Library GNU Public License") and you should have received a copy of this license with this software and its documents.

BUGS Quite possibly. In particular, portability has not been tested under many platforms as the current developers have limited OS resources. Feedback, access to alternative platforms, bug-reports, and questions are all welcome - please go to the distcache website and subscribe to the distcache-users mail list.

SEE ALSO dc_server(1) Distributed caching server.

dc_client(1) Distributed caching client proxy

dc_snoop(1) Distcache protocol analyser and debugging tool.

http://www.distcache.org/ Distcache home page.

AUTHOR This toolkit was designed and implemented by Geoff Thorpe for Crypto- graphic Appliances Incorporated. Since the project was released into open source, it has a home page and a project environment where devel- opment, mailing lists, and releases are organised. For problems with the software or this man page please check for new releases at the project web-site below, mail the users mailing list described there, or contact the author at geoff@geoffthorpe.net.

Home Page: http://www.distcache.org

1.4.5 2004.03.23 DISTCACHE(8)