doc/apt.conf.5

   1 .\"     Title: apt.conf
   2 .\"    Author: Jason Gunthorpe
   3 .\" Generator: DocBook XSL Stylesheets v1.71.0 <http://docbook.sf.net/>
   4 .\"      Date: 29 February 2004
   5 .\"    Manual:
   6 .\"    Source: Linux
   7 .\"
   8 .TH "APT.CONF" "5" "29 February 2004" "Linux" ""
   9 .\" disable hyphenation
  10 .nh
  11 .\" disable justification (adjust text to left margin only)
  12 .ad l
  13 .SH "NAME"
  14 apt.conf \- Configuration file for APT
  15 .SH "DESCRIPTION"
  16 .PP
  17 \fIapt.conf\fR
  18 is the main configuration file for the APT suite of tools, all tools make use of the configuration file and a common command line parser to provide a uniform environment. When an APT tool starts up it will read the configuration specified by the
  19 \fBAPT_CONFIG\fR
  20 environment variable (if any) and then read the files in
  21 Dir::Etc::Parts
  22 then read the main configuration file specified by
  23 Dir::Etc::main
  24 then finally apply the command line options to override the configuration directives, possibly loading even more config files.
  25 .PP
  26 The configuration file is organized in a tree with options organized into functional groups. option specification is given with a double colon notation, for instance
  27 APT::Get::Assume\-Yes
  28 is an option within the APT tool group, for the Get tool. options do not inherit from their parent groups.
  29 .PP
  30 Syntacticly the configuration language is modeled after what the ISC tools such as bind and dhcp use. Lines starting with
  31 //
  32 are treated as comments (ignored). Each line is of the form
  33 APT::Get::Assume\-Yes "true";
  34 The trailing semicolon is required and the quotes are optional. A new scope can be opened with curly braces, like:
  35 .sp
  36 .RS 3n
  37 .nf
  38
  39 APT {
  40   Get {
  41     Assume\-Yes "true";
  42     Fix\-Broken "true";
  43   };
  44 };
  45 .fi
  46 .RE
  47 .PP
  48 with newlines placed to make it more readable. Lists can be created by opening a scope and including a single word enclosed in quotes followed by a semicolon. Multiple entries can be included, each separated by a semicolon.
  49 .sp
  50 .RS 3n
  51 .nf
  52
  53 DPkg::Pre\-Install\-Pkgs {"/usr/sbin/dpkg\-preconfigure \-\-apt";};
  54 .fi
  55 .RE
  56 .PP
  57 In general the sample configuration file in
  58 \fI/usr/share/doc/apt/examples/apt.conf\fR
  59 \fI/usr/share/doc/apt/examples/configure\-index.gz\fR
  60 is a good guide for how it should look.
  61 .PP
  62 Two specials are allowed,
  63 #include
  64 and
  65 #clear
  66 #include
  67 will include the given file, unless the filename ends in a slash, then the whole directory is included.
  68 #clear
  69 is used to erase a list of names.
  70 .PP
  71 All of the APT tools take a \-o option which allows an arbitrary configuration directive to be specified on the command line. The syntax is a full option name (APT::Get::Assume\-Yes
  72 for instance) followed by an equals sign then the new value of the option. Lists can be appended too by adding a trailing :: to the list name.
  73 .SH "THE APT GROUP"
  74 .PP
  75 This group of options controls general APT behavior as well as holding the options for all of the tools.
  76 .PP
  77 Architecture
  78 .RS 3n
  79 System Architecture; sets the architecture to use when fetching files and parsing package lists. The internal default is the architecture apt was compiled for.
  80 .RE
  81 .PP
  82 Ignore\-Hold
  83 .RS 3n
  84 Ignore Held packages; This global option causes the problem resolver to ignore held packages in its decision making.
  85 .RE
  86 .PP
  87 Clean\-Installed
  88 .RS 3n
  89 Defaults to on. When turned on the autoclean feature will remove any packages which can no longer be downloaded from the cache. If turned off then packages that are locally installed are also excluded from cleaning \- but note that APT provides no direct means to reinstall them.
  90 .RE
  91 .PP
  92 Immediate\-Configure
  93 .RS 3n
  94 Disable Immediate Configuration; This dangerous option disables some of APT's ordering code to cause it to make fewer dpkg calls. Doing so may be necessary on some extremely slow single user systems but is very dangerous and may cause package install scripts to fail or worse. Use at your own risk.
  95 .RE
  96 .PP
  97 Force\-LoopBreak
  98 .RS 3n
  99 Never Enable this option unless you \-really\- know what you are doing. It permits APT to temporarily remove an essential package to break a Conflicts/Conflicts or Conflicts/Pre\-Depend loop between two essential packages. SUCH A LOOP SHOULD NEVER EXIST AND IS A GRAVE BUG. This option will work if the essential packages are not tar, gzip, libc, dpkg, bash or anything that those packages depend on.
 100 .RE
 101 .PP
 102 Cache\-Limit
 103 .RS 3n
 104 APT uses a fixed size memory mapped cache file to store the 'available' information. This sets the size of that cache (in bytes).
 105 .RE
 106 .PP
 107 Build\-Essential
 108 .RS 3n
 109 Defines which package(s) are considered essential build dependencies.
 110 .RE
 111 .PP
 112 Get
 113 .RS 3n
 114 The Get subsection controls the
 115 \fBapt\-get\fR(8)
 116 tool, please see its documentation for more information about the options here.
 117 .RE
 118 .PP
 119 Cache
 120 .RS 3n
 121 The Cache subsection controls the
 122 \fBapt\-cache\fR(8)
 123 tool, please see its documentation for more information about the options here.
 124 .RE
 125 .PP
 126 CDROM
 127 .RS 3n
 128 The CDROM subsection controls the
 129 \fBapt\-cdrom\fR(8)
 130 tool, please see its documentation for more information about the options here.
 131 .RE
 132 .SH "THE ACQUIRE GROUP"
 133 .PP
 134 The
 135 Acquire
 136 group of options controls the download of packages and the URI handlers.
 137 .PP
 138 Queue\-Mode
 139 .RS 3n
 140 Queuing mode;
 141 Queue\-Mode
 142 can be one of
 143 host
 144 or
 145 access
 146 which determines how APT parallelizes outgoing connections.
 147 host
 148 means that one connection per target host will be opened,
 149 access
 150 means that one connection per URI type will be opened.
 151 .RE
 152 .PP
 153 Retries
 154 .RS 3n
 155 Number of retries to perform. If this is non\-zero APT will retry failed files the given number of times.
 156 .RE
 157 .PP
 158 Source\-Symlinks
 159 .RS 3n
 160 Use symlinks for source archives. If set to true then source archives will be symlinked when possible instead of copying. True is the default.
 161 .RE
 162 .PP
 163 http
 164 .RS 3n
 165 HTTP URIs; http::Proxy is the default http proxy to use. It is in the standard form of
 166 http://[[user][:pass]@]host[:port]/. Per host proxies can also be specified by using the form
 167 http::Proxy::<host>
 168 with the special keyword
 169 DIRECT
 170 meaning to use no proxies. The
 171 \fBhttp_proxy\fR
 172 environment variable will override all settings.
 173 .sp
 174 Three settings are provided for cache control with HTTP/1.1 compliant proxy caches.
 175 No\-Cache
 176 tells the proxy to not use its cached response under any circumstances,
 177 Max\-Age
 178 is sent only for index files and tells the cache to refresh its object if it is older than the given number of seconds. Debian updates its index files daily so the default is 1 day.
 179 No\-Store
 180 specifies that the cache should never store this request, it is only set for archive files. This may be useful to prevent polluting a proxy cache with very large .deb files. Note: Squid 2.0.2 does not support any of these options.
 181 .sp
 182 The option
 183 timeout
 184 sets the timeout timer used by the method, this applies to all things including connection timeout and data timeout.
 185 .sp
 186 One setting is provided to control the pipeline depth in cases where the remote server is not RFC conforming or buggy (such as Squid 2.0.2)
 187 Acquire::http::Pipeline\-Depth
 188 can be a value from 0 to 5 indicating how many outstanding requests APT should send. A value of zero MUST be specified if the remote host does not properly linger on TCP connections \- otherwise data corruption will occur. Hosts which require this are in violation of RFC 2068.
 189 .RE
 190 .PP
 191 ftp
 192 .RS 3n
 193 FTP URIs; ftp::Proxy is the default proxy server to use. It is in the standard form of
 194 ftp://[[user][:pass]@]host[:port]/
 195 and is overridden by the
 196 \fBftp_proxy\fR
 197 environment variable. To use a ftp proxy you will have to set the
 198 ftp::ProxyLogin
 199 script in the configuration file. This entry specifies the commands to send to tell the proxy server what to connect to. Please see
 200 \fI/usr/share/doc/apt/examples/configure\-index.gz\fR
 201 for an example of how to do this. The subsitution variables available are
 202 $(PROXY_USER)
 203 $(PROXY_PASS)
 204 $(SITE_USER)
 205 $(SITE_PASS)
 206 $(SITE)
 207 and
 208 $(SITE_PORT)
 209 Each is taken from it's respective URI component.
 210 .sp
 211 The option
 212 timeout
 213 sets the timeout timer used by the method, this applies to all things including connection timeout and data timeout.
 214 .sp
 215 Several settings are provided to control passive mode. Generally it is safe to leave passive mode on, it works in nearly every environment. However some situations require that passive mode be disabled and port mode ftp used instead. This can be done globally, for connections that go through a proxy or for a specific host (See the sample config file for examples).
 216 .sp
 217 It is possible to proxy FTP over HTTP by setting the
 218 \fBftp_proxy\fR
 219 environment variable to a http url \- see the discussion of the http method above for syntax. You cannot set this in the configuration file and it is not recommended to use FTP over HTTP due to its low efficiency.
 220 .sp
 221 The setting
 222 ForceExtended
 223 controls the use of RFC2428
 224 EPSV
 225 and
 226 EPRT
 227 commands. The defaut is false, which means these commands are only used if the control connection is IPv6. Setting this to true forces their use even on IPv4 connections. Note that most FTP servers do not support RFC2428.
 228 .RE
 229 .PP
 230 cdrom
 231 .RS 3n
 232 CDROM URIs; the only setting for CDROM URIs is the mount point,
 233 cdrom::Mount
 234 which must be the mount point for the CDROM drive as specified in
 235 \fI/etc/fstab\fR. It is possible to provide alternate mount and unmount commands if your mount point cannot be listed in the fstab (such as an SMB mount and old mount packages). The syntax is to put
 236 .sp
 237 .RS 3n
 238 .nf
 239 "/cdrom/"::Mount "foo";
 240 .fi
 241 .RE
 242 .sp
 243 within the cdrom block. It is important to have the trailing slash. Unmount commands can be specified using UMount.
 244 .RE
 245 .PP
 246 gpgv
 247 .RS 3n
 248 GPGV URIs; the only option for GPGV URIs is the option to pass additional parameters to gpgv.
 249 gpgv::Options
 250 Additional options passed to gpgv.
 251 .RE
 252 .SH "DIRECTORIES"
 253 .PP
 254 The
 255 Dir::State
 256 section has directories that pertain to local state information.
 257 lists
 258 is the directory to place downloaded package lists in and
 259 status
 260 is the name of the dpkg status file.
 261 preferences
 262 is the name of the APT preferences file.
 263 Dir::State
 264 contains the default directory to prefix on all sub items if they do not start with
 265 \fI/\fR
 266 or
 267 \fI./\fR.
 268 .PP
 269 Dir::Cache
 270 contains locations pertaining to local cache information, such as the two package caches
 271 srcpkgcache
 272 and
 273 pkgcache
 274 as well as the location to place downloaded archives,
 275 Dir::Cache::archives. Generation of caches can be turned off by setting their names to be blank. This will slow down startup but save disk space. It is probably prefered to turn off the pkgcache rather than the srcpkgcache. Like
 276 Dir::State
 277 the default directory is contained in
 278 Dir::Cache
 279 .PP
 280 Dir::Etc
 281 contains the location of configuration files,
 282 sourcelist
 283 gives the location of the sourcelist and
 284 main
 285 is the default configuration file (setting has no effect, unless it is done from the config file specified by
 286 \fBAPT_CONFIG\fR).
 287 .PP
 288 The
 289 Dir::Parts
 290 setting reads in all the config fragments in lexical order from the directory specified. After this is done then the main config file is loaded.
 291 .PP
 292 Binary programs are pointed to by
 293 Dir::Bin.
 294 Dir::Bin::Methods
 295 specifies the location of the method handlers and
 296 gzip,
 297 dpkg,
 298 apt\-get
 299 dpkg\-source
 300 dpkg\-buildpackage
 301 and
 302 apt\-cache
 303 specify the location of the respective programs.
 304 .SH "APT IN DSELECT"
 305 .PP
 306 When APT is used as a
 307 \fBdselect\fR(8)
 308 method several configuration directives control the default behaviour. These are in the
 309 DSelect
 310 section.
 311 .PP
 312 Clean
 313 .RS 3n
 314 Cache Clean mode; this value may be one of always, prompt, auto, pre\-auto and never. always and prompt will remove all packages from the cache after upgrading, prompt (the default) does so conditionally. auto removes only those packages which are no longer downloadable (replaced with a new version for instance). pre\-auto performs this action before downloading new packages.
 315 .RE
 316 .PP
 317 options
 318 .RS 3n
 319 The contents of this variable is passed to
 320 \fBapt\-get\fR(8)
 321 as command line options when it is run for the install phase.
 322 .RE
 323 .PP
 324 Updateoptions
 325 .RS 3n
 326 The contents of this variable is passed to
 327 \fBapt\-get\fR(8)
 328 as command line options when it is run for the update phase.
 329 .RE
 330 .PP
 331 PromptAfterUpdate
 332 .RS 3n
 333 If true the [U]pdate operation in
 334 \fBdselect\fR(8)
 335 will always prompt to continue. The default is to prompt only on error.
 336 .RE
 337 .SH "HOW APT CALLS DPKG"
 338 .PP
 339 Several configuration directives control how APT invokes
 340 \fBdpkg\fR(8). These are in the
 341 DPkg
 342 section.
 343 .PP
 344 options
 345 .RS 3n
 346 This is a list of options to pass to dpkg. The options must be specified using the list notation and each list item is passed as a single argument to
 347 \fBdpkg\fR(8).
 348 .RE
 349 .PP
 350 Pre\-Invoke, Post\-Invoke
 351 .RS 3n
 352 This is a list of shell commands to run before/after invoking
 353 \fBdpkg\fR(8). Like
 354 options
 355 this must be specified in list notation. The commands are invoked in order using
 356 \fI/bin/sh\fR, should any fail APT will abort.
 357 .RE
 358 .PP
 359 Pre\-Install\-Pkgs
 360 .RS 3n
 361 This is a list of shell commands to run before invoking dpkg. Like
 362 options
 363 this must be specified in list notation. The commands are invoked in order using
 364 \fI/bin/sh\fR, should any fail APT will abort. APT will pass to the commands on standard input the filenames of all .deb files it is going to install, one per line.
 365 .sp
 366 Version 2 of this protocol dumps more information, including the protocol version, the APT configuration space and the packages, files and versions being changed. Version 2 is enabled by setting
 367 DPkg::Tools::options::cmd::Version
 368 to 2.
 369 cmd
 370 is a command given to
 371 Pre\-Install\-Pkgs.
 372 .RE
 373 .PP
 374 Run\-Directory
 375 .RS 3n
 376 APT chdirs to this directory before invoking dpkg, the default is
 377 \fI/\fR.
 378 .RE
 379 .PP
 380 Build\-options
 381 .RS 3n
 382 These options are passed to
 383 \fBdpkg\-buildpackage\fR(1)
 384 when compiling packages, the default is to disable signing and produce all binaries.
 385 .RE
 386 .SH "DEBUG OPTIONS"
 387 .PP
 388 Most of the options in the
 389 debug
 390 section are not interesting to the normal user, however
 391 Debug::pkgProblemResolver
 392 shows interesting output about the decisions dist\-upgrade makes.
 393 Debug::NoLocking
 394 disables file locking so APT can do some operations as non\-root and
 395 Debug::pkgDPkgPM
 396 will print out the command line for each dpkg invokation.
 397 Debug::IdentCdrom
 398 will disable the inclusion of statfs data in CDROM IDs.
 399 Debug::Acquire::gpgv
 400 Debugging of the gpgv method.
 401 .SH "EXAMPLES"
 402 .PP
 403 \fI/usr/share/doc/apt/examples/configure\-index.gz\fR
 404 is a configuration file showing example values for all possible options.
 405 .SH "FILES"
 406 .PP
 407 \fI/etc/apt/apt.conf\fR
 408 .SH "SEE ALSO"
 409 .PP
 410 \fBapt\-cache\fR(8),
 411 \fBapt\-config\fR(8),
 412 \fBapt_preferences\fR(5).
 413 .SH "BUGS"
 414 .PP
 415 [1]\&\fIAPT bug page\fR. If you wish to report a bug in APT, please see
 416 \fI/usr/share/doc/debian/bug\-reporting.txt\fR
 417 or the
 418 \fBreportbug\fR(1)
 419 command.
 420 .SH "AUTHORS"
 421 .PP
 422 \fBJason Gunthorpe\fR
 423 .sp -1n
 424 .IP "" 3n
 425 Author.
 426 .PP
 427 \fBAPT team\fR
 428 .sp -1n
 429 .IP "" 3n
 430 Author.
 431 .SH "REFERENCES"
 432 .TP 3
 433 1.\ APT bug page
 434 \%http://bugs.debian.org/src:apt