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) GDBM(3) GDBM(3)

NAME GDBM - The GNU database manager. Includes dbm and ndbm compatability. (Version 1.8.)

SYNOPSIS #include <gdbm.h>

extern gdbm_error gdbm_errno

extern char *gdbm_version

GDBM_FILE gdbm_open (name, block_size, read_write, mode, fatal_func) char * name; int block_size, read_write, mode; void (*fatal_func) ();

void gdbm_close (dbf) GDBM_FILE dbf;

int gdbm_store (dbf, key, content, flag) GDBM_FILE dbf; datum key, content; int flag;

datum gdbm_fetch (dbf, key) GDBM_FILE dbf; datum key;

int gdbm_delete (dbf, key) GDBM_FILE dbf; datum key;

datum gdbm_firstkey (dbf) GDBM_FILE dbf;

datum gdbm_nextkey (dbf, key) GDBM_FILE dbf; datum key;

int gdbm_reorganize (dbf) GDBM_FILE dbf;

void gdbm_sync (dbf) GDBM_FILE dbf;

int gdbm_exists (dbf, key) GDBM_FILE dbf; datum key;

char * gdbm_strerror (errno) gdbm_error errno;

int gdbm_setopt (dbf, option, value, size) GDBM_FILE dbf; int option; int *value; int size;

int gdbm_fdesc (dbf) GDBM_FILE dbf;

DBM Compatability routines:

#include <dbm.h>

int dbminit (name) char *name;

int store (key, content) datum key, content;

datum fetch (key) datum key;

int delete (key) datum key;

datum firstkey ()

datum nextkey (key) datum key;

int dbmclose ()

NDBM Compatability routines:

#include <ndbm.h>

DBM *dbm_open (name, flags, mode) char *name; int flags, mode;

void dbm_close (file) DBM *file;

datum dbm_fetch (file, key) DBM *file; datum key;

int dbm_store (file, key, content, flags) DBM *file; datum key, content; int flags;

int dbm_delete (file, key) DBM *file; datum key;

datum dbm_firstkey (file) DBM *file;

datum dbm_nextkey (file) DBM *file;

int dbm_error (file) DBM *file;

int dbm_clearerr (file) DBM *file;

int dbm_pagfno (file) DBM *file;

int dbm_dirfno (file) DBM *file;

int dbm_rdonly (file) DBM *file;

DESCRIPTION GNU dbm is a library of routines that manages data files that contain key/data pairs. The access provided is that of storing, retrieval, and deletion by key and a non-sorted traversal of all keys. A process is allowed to use multiple data files at the same time.

A process that opens a gdbm file is designated as a "reader" or a "writer". Only one writer may open a gdbm file and many readers may open the file. Readers and writers can not open the gdbm file at the same time. The procedure for opening a gdbm file is:

GDBM_FILE dbf;

dbf = gdbm_open ( name, block_size, read_write, mode, fatal_func )

Name is the name of the file (the complete name, gdbm does not append any characters to this name). Block_size is the size of a single transfer from disk to memory. This parameter is ignored unless the file is a new file. The minimum size is 512. If it is less than 512, dbm will use the stat block size for the file system. Read_write can have one of the following values: GDBM_READER reader GDBM_WRITER writer GDBM_WRCREAT writer - if database does not exist create new one GDBM_NEWDB writer - create new database regardless if one exists For the last three (writers of the database) the following may be added added to read_write by bitwise or: GDBM_SYNC, which causes all database operations to be synchronized to the disk, and GDBM_NOLOCK, which pre- vents the library from performing any locking on the database file. The option GDBM_FAST is now obsolete, since gdbm defaults to no-sync mode. Mode is the file mode (see chmod(2) and open(2)) if the file is cre- ated. (*Fatal_func) () is a function for dbm to call if it detects a fatal error. The only parameter of this function is a string. If the value of 0 is provided, gdbm will use a default function.

The return value dbf is the pointer needed by all other routines to access that gdbm file. If the return is the NULL pointer, gdbm_open was not successful. The errors can be found in gdbm_errno for gdbm errors and in errno for system errors. (For error codes, see gdbmer- rno.h.)

In all of the following calls, the parameter dbf refers to the pointer returned from gdbm_open.

It is important that every file opened is also closed. This is needed to update the reader/writer count on the file. This is done by:

gdbm_close (dbf);

The database is used by 3 primary routines. The first stores data in the database.

ret = gdbm_store ( dbf, key, content, flag )

Dbf is the pointer returned by gdbm_open. Key is the key data. Con- tent is the data to be associated with the key. Flag can have one of the following values: GDBM_INSERT insert only, generate an error if key exists GDBM_REPLACE replace contents if key exists.

If a reader calls gdbm_store, the return value will be -1. If called with GDBM_INSERT and key is in the database, the return value will be 1. Otherwise, the return value is 0.

NOTICE: If you store data for a key that is already in the data base, gdbm replaces the old data with the new data if called with GDBM_REPLACE. You do not get two data items for the same key and you do not get an error from gdbm_store.

NOTICE: The size in gdbm is not restricted like dbm or ndbm. Your data can be as large as you want.

To search for some data:

content = gdbm_fetch ( dbf, key )

Dbf is the pointer returned by gdbm_open. Key is the key data.

If the dptr element of the return value is NULL, no data was found. Otherwise the return value is a pointer to the found data. The storage space for the dptr element is allocated using malloc(3C). Gdbm does not automatically free this data. It is the programmers responsibil- ity to free this storage when it is no longer needed.

To search for some data, without retrieving it:

ret = gdbm_exists ( dbf, key )

Dbf is the pointer returned by gdbm_open. Key is the key data to search for.

If the key is found within the database, the return value ret will be true. If nothing appropiate is found, ret will be false. This routine is useful for checking for the existance of a record, without perform- ing the memory allocation done by gdbm_fetch.

To remove some data from the database:

ret = gdbm_delete ( dbf, key )

Dbf is the pointer returned by gdbm_open. Key is the key data.

The return value is -1 if the item is not present or the requester is a reader. The return value is 0 if there was a successful delete.

The next two routines allow for accessing all items in the database. This access is not key sequential, but it is guaranteed to visit every key in the database once. (The order has to do with the hash values.)

key = gdbm_firstkey ( dbf )

nextkey = gdbm_nextkey ( dbf, key )

Dbf is the pointer returned by gdbm_open. Key is the key data.

The return values are both of type datum. If the dptr element of the return value is NULL, there is no first key or next key. Again notice that dptr points to data allocated by malloc(3C) and gdbm will not free it for you.

These functions were intended to visit the database in read-only algo- rithms, for instance, to validate the database or similar operations.

File visiting is based on a hash table . gdbm_delete re-arranges the hash table to make sure that any collisions in the table do not leave some item un-findable. The original key order is NOT guaran- teed to remain unchanged in ALL instances. It is possible that some key will not be visited if a loop like the following is executed:

key = gdbm_firstkey ( dbf ); while ( key.dptr ) { nextkey = gdbm_nextkey ( dbf, key ); if ( some condition ) { gdbm_delete ( dbf, key ); free ( key.dptr ); } key = nextkey; }

The following routine should be used very infrequently.

ret = gdbm_reorganize ( dbf )

If you have had a lot of deletions and would like to shrink the space used by the gdbm file, this routine will reorganize the database. Gdbm will not shorten the length of a gdbm file except by using this reorga- nization. (Deleted file space will be reused.)

Unless your database was opened with the GDBM_SYNC flag, gdbm does not wait for writes to be flushed to the disk before continuing. The following routine can be used to guarantee that the database is physi- cally written to the disk file.

gdbm_sync ( dbf )

It will not return until the disk file state is syncronized with the in-memory state of the database.

To convert a gdbm error code into English text, use this routine:

ret = gdbm_strerror ( errno )

Where errno is of type gdbm_error, usually the global variable gdbm_errno. The appropiate phrase is returned.

Gdbm now supports the ability to set certain options on an already open database.

ret = gdbm_setopt ( dbf, option, value, size )

Where dbf is the return value from a previous call to gdbm_open, and option specifies which option to set. The valid options are currently:

GDBM_CACHESIZE - Set the size of the internal bucket cache. This option may only be set once on each GDBM_FILE descriptor, and is set automatically to 100 upon the first access to the database.

GDBM_FASTMODE - Set fast mode to either on or off. This allows fast mode to be toggled on an already open and active database. value (see below) should be set to either TRUE or FALSE. This option is now obsolete.

GDBM_SYNCMODE - Turn on or off file system synchronization opera- tions. This setting defaults to off; value (see below) should be set to either TRUE or FALSE.

GDBM_CENTFREE - Set central free block pool to either on or off. The default is off, which is how previous versions of Gdbm handled free blocks. If set, this option causes all subsequent free blocks to be placed in the global pool, allowing (in thoery) more file space to be reused more quickly. value (see below) should be set to either TRUE or FALSE. NOTICE: This feature is still under study.

GDBM_COALESCEBLKS - Set free block merging to either on or off. The default is off, which is how previous versions of Gdbm handled free blocks. If set, this option causes adjacent free blocks to be merged. This can become a CPU expensive process with time, though, especially if used in conjunction with GDBM_CENTFREE. value (see below) should be set to either TRUE or FALSE. NOTICE: This feature is still under study.

value is the value to set option to, specified as an integer pointer. size is the size of the data pointed to by value. The return value will be -1 upon failure, or 0 upon success. The global variable gdbm_errno will be set upon failure.

For instance, to set a database to use a cache of 10, after opening it with gdbm_open, but prior to accessing it in any way, the following code could be used:

int value = 10;

ret = gdbm_setopt( dbf, GDBM_CACHESIZE, &value, sizeof(int));

If the database was opened with the GDBM_NOLOCK flag, the user may wish to perform their own file locking on the database file in order to pre- vent multiple writers operating on the same file simultaneously.

In order to support this, the gdbm_fdesc routine is provided.

ret = gdbm_fdesc ( dbf )

Where dbf is the return value from a previous call to gdbm_open. The return value will be the file descriptor of the database.

The following two external variables may be useful:

gdbm_errno is the variable that contains more information about gdbm errors. (gdbm.h has the definitions of the error values and defines gdbm_errno as an external variable.) gdbm_version is the string containing the version information.

There are a few more things of interest. First, gdbm files are not "sparse". You can copy them with the UNIX cp(1) command and they will not expand in the copying process. Also, there is a compatibility mode for use with programs that already use UNIX dbm. In this compatibility mode, no gdbm file pointer is required by the programmer, and only one file may be opened at a time. All users in compatibility mode are assumed to be writers. If the gdbm file is a read only, it will fail as a writer, but will also try to open it as a reader. All returned pointers in datum structures point to data that gdbm WILL free. They should be treated as static pointers (as standard UNIX dbm does).

LINKING This library is accessed by specifying -lgdbm as the last parameter to the compile line, e.g.:

gcc -o prog prog.c -lgdbm

ENVIRONMENT VARIABLES NDBM_LOCK - When the NDBM interface is used, the database file is locked by default. Locking might degrade performance when used on a NFS share. This environment variable can be set to false to tell GDBM not to lock the database file.

SEE ALSO dbm, ndbm

AUTHOR by Philip A. Nelson and Jason Downs. Copyright (C) 1990 - 1999 Free Software Foundation, Inc.

GDBM is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version.

GDBM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT- NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with GDBM; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

You may contact the original author by: e-mail: phil@cs.wwu.edu us-mail: Philip A. Nelson Computer Science Department Western Washington University Bellingham, WA 98226

You may contact the current maintainer by: e-mail: downsj@downsj.com

5/19/99 GDBM(3)