</p>
<p>
- The <var>date</var> must be in RFC822 format<footnote>
+ The <var>date</var> has the following format<footnote>
This is generated by <tt>date -R</tt>.
- </footnote>; it must include the time zone specified
- numerically, with the time zone name or abbreviation
- optionally present as a comment in parentheses.
+ </footnote> (compatible and with the same semantics of
+ RFC 2822 and RFC 5322):
+ <example>day-of-week, dd month yyyy hh:mm:ss +zzzz</example>
+ where:
+ <list compact="compact">
+ <item>day-of week is one of: Mon, Tue, Wed, Thu, Fri, Sat, Sun</item>
+ <item>dd is a one- or two-digit day of the month (01-31)</item>
+ <item>month is one of: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec</item>
+ <item>yyyy is the four-digit year (e.g. 2010)</item>
+ <item>hh is the two-digit hour (00-23</item>
+ <item>mm is the two-digit minutes (00-59)</item>
+ <item>ss is the two-digit seconds (00-60)</item>
+ <item>
+ +zzzz or -zzzz is the the time zone offset from Coordinated Universal
+ Time (UTC). "+" indicates that the time is ahead of (i.e., east of) UTC
+ and "-" indicates that the time is behind (i.e., west of) UTC. The
+ first two digits indicate the hour difference from UTC and the last
+ two digits indicate the number of additional minutes difference from
+ UTC. The last two digits must be in the range 00-59.
+ </item>
+ </list>
</p>
<p>
<item>
An architecture wildcard identifying a set of Debian
machine architectures, see <ref id="arch-wildcard-spec">.
+ <tt>any</tt> matches all Debian machine architectures
+ and is the most frequently used.
</item>
<item>
<tt>all</tt>, which indicates an
<p>
In the main <file>debian/control</file> file in the source
- package, this field may contain the special value <tt>all</tt>
- or a list of specific and wildcard architectures separated by
- spaces. If <tt>all</tt> appears, that value must be the
- entire contents of the field. Most packages will use
- either <tt>any</tt> or <tt>all</tt>. Specifying a specific
- list of architectures is for the minority of cases where a
+ package, this field may contain the special
+ value <tt>all</tt>, the special architecture
+ wildcard <tt>any</tt>, or a list of specific and wildcard
+ architectures separated by spaces. If <tt>all</tt>
+ or <tt>any</tt> appears, that value must be the entire
+ contents of the field. Most packages will use
+ either <tt>all</tt> or <tt>any</tt>.
+ </p>
+
+ <p>
+ Specifying a specific list of architectures indicates that the
+ source will build an architecture-dependent package only on
+ architectures included in the list. Specifying a list of
+ architecture wildcards indicates that the source will build an
+ architecture-dependent package on only those architectures
+ that match any of the specified architecture wildcards.
+ Specifying a list of architectures or architecture wildcards
+ other than <tt>any</tt> is for the minority of cases where a
program is not portable or is not useful on some
- architectures, and where possible the program should be made
+ architectures. Where possible, the program should be made
portable instead.
</p>
- <p>
- Specifying a list of architecture wildcards indicates that
- the source will build an architecture-dependent package on
- the union of the lists of architectures from the expansion
- of each specified architecture wildcard, and will only
- work correctly on the architectures in the union of the
- lists.<footnote>
- Use of architecture wildcards other than <tt>all</tt> is for
- a minority of cases where the program is not portable and
- should not be used for most packages. Wildcards are not
- expanded into a list of known architectures before comparing
- to the build architecture. Instead, the build architecture
- is matched against any wildcards and this package is built
- if any wildcard matches.
- </footnote>
- </p>
-
<p>
In the source package control file <file>.dsc</file>, this
- field may contain either the special value <tt>any</tt> or a
- list of architectures separated by spaces. If a list is given,
- it may include (or consist solely of) the special value
- <tt>all</tt>. In other words, in <file>.dsc</file> files
- unlike the <file>debian/control</file>, <tt>all</tt> may occur
- in combination with specific architectures. The
- <tt>Architecture</tt> field in the source package control file
- <file>.dsc</file> is generally constructed from the
- <tt>Architecture</tt> fields in the
- <file>debian/control</file> in the source package.
+ field may contain either the architecture
+ wildcard <tt>any</tt> or a list of architectures and
+ architecture wildcards separated by spaces. If a list is
+ given, it may include (or consist solely of) the special
+ value <tt>all</tt>. In other words, in <file>.dsc</file>
+ files unlike the <file>debian/control</file>, <tt>all</tt> may
+ occur in combination with specific architectures.
+ The <tt>Architecture</tt> field in the source package control
+ file <file>.dsc</file> is generally constructed from
+ the <tt>Architecture</tt> fields in
+ the <file>debian/control</file> in the source package.
</p>
<p>
package is also being uploaded, the special
entry <tt>source</tt> is also present. <tt>all</tt> will be
present if any architecture-independent packages are being
- uploaded. Architecture wildcards such as <tt>any</tt> may
+ uploaded. Architecture wildcards such as <tt>any</tt> must
never occur in the <tt>Architecture</tt> field in
the <file>.changes</file> file.
</p>
<em>not</em> intended to cope with version numbers containing
strings of letters which the package management system cannot
interpret (such as <tt>ALPHA</tt> or <tt>pre-</tt>), or with
- silly orderings (the author of this manual has heard of a
- package whose versions went <tt>1.1</tt>, <tt>1.2</tt>,
- <tt>1.3</tt>, <tt>1</tt>, <tt>2.1</tt>, <tt>2.2</tt>,
- <tt>2</tt> and so forth).
+ silly orderings.<footnote>
+ The author of this manual has heard of a package whose
+ versions went <tt>1.1</tt>, <tt>1.2</tt>, <tt>1.3</tt>,
+ <tt>1</tt>, <tt>2.1</tt>, <tt>2.2</tt>, <tt>2</tt> and so
+ forth.
+ </footnote>
</p>
</sect1>
<heading>Controlling terminal for maintainer scripts</heading>
<p>
- The maintainer scripts are guaranteed to run with a
- controlling terminal and can interact with the user.
- Because these scripts may be executed with standard output
- redirected into a pipe for logging purposes, Perl scripts
- should set unbuffered output by setting <tt>$|=1</tt> so
- that the output is printed immediately rather than being
- buffered.
+ Maintainer scripts are not guaranteed to run with a controlling
+ terminal and may not be able to interact with the user. They
+ must be able to fall back to noninteractive behavior if no
+ controlling terminal is available. Maintainer scripts that
+ prompt via a program conforming to the Debian Configuration
+ Management Specification (see <ref id="maintscriptprompt">) may
+ assume that program will handle falling back to noninteractive
+ behavior.
+ </p>
+
+ <p>
+ For high-priority prompts without a reasonable default answer,
+ maintainer scripts may abort if there is no controlling
+ terminal. However, this situation should be avoided if at all
+ possible, since it prevents automated or unattended installs.
+ In most cases, users will consider this to be a bug in the
+ package.
</p>
</sect>
+
<sect id="exitstatus">
<heading>Exit status</heading>
</p>
</sect1>
- <sect1>
+ <sect1 id="writing-init">
<heading>Writing the scripts</heading>
<p>
option.
</p>
+ <p>
+ Be careful of using <tt>set -e</tt> in <file>init.d</file>
+ scripts. Writing correct <file>init.d</file> scripts requires
+ accepting various error exit statuses when daemons are already
+ running or already stopped without aborting
+ the <file>init.d</file> script, and common <file>init.d</file>
+ function libraries are not safe to call with <tt>set -e</tt>
+ in effect<footnote>
+ <tt>/lib/lsb/init-functions</tt>, which assists in writing
+ LSB-compliant init scripts, may fail if <tt>set -e</tt> is
+ in effect and echoing status messages to the console fails,
+ for example.
+ </footnote>. For <tt>init.d</tt> scripts, it's often easier
+ to not use <tt>set -e</tt> and instead check the result of
+ each command separately.
+ </p>
+
<p>
If a service reloads its configuration automatically (as
in the case of <prgn>cron</prgn>, for example), the
language currently used to implement it.
</p>
<p>
- Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>)
- should almost certainly start with <tt>set -e</tt> so that
- errors are detected. Every script should use
- <tt>set -e</tt> or check the exit status of <em>every</em>
- command.
+ Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>) other than
+ <file>init.d</file> scripts should almost certainly start
+ with <tt>set -e</tt> so that errors are detected.
+ <file>init.d</file> scripts are something of a special case, due
+ to how frequently they need to call commands that are allowed to
+ fail, and it may instead be easier to check the exit status of
+ commands directly. See <ref id="writing-init"> for more
+ information about writing <file>init.d</file> scripts.
+ </p>
+ <p>
+ Every script should use <tt>set -e</tt> or check the exit status
+ of <em>every</em> command.
</p>
-
<p>
Scripts may assume that <file>/bin/sh</file> implements the
SUSv3 Shell Command Language<footnote>
<p>
If a program needs to specify an <em>architecture specification
- string</em> in some place, it should select one of the
- strings provided by <tt>dpkg-architecture -L</tt>. The
- strings are in the format
- <tt><var>os</var>-<var>arch</var></tt>, though the OS part
- is sometimes elided, as when the OS is Linux.<footnote>
- <p>Currently, the strings are:
- i386 ia64 alpha amd64 armeb arm hppa m32r m68k mips
- mipsel powerpc ppc64 s390 s390x sh3 sh3eb sh4 sh4eb
- sparc darwin-i386 darwin-ia64 darwin-alpha darwin-amd64
- darwin-armeb darwin-arm darwin-hppa darwin-m32r
- darwin-m68k darwin-mips darwin-mipsel darwin-powerpc
- darwin-ppc64 darwin-s390 darwin-s390x darwin-sh3
- darwin-sh3eb darwin-sh4 darwin-sh4eb darwin-sparc
- freebsd-i386 freebsd-ia64 freebsd-alpha freebsd-amd64
- freebsd-armeb freebsd-arm freebsd-hppa freebsd-m32r
- freebsd-m68k freebsd-mips freebsd-mipsel freebsd-powerpc
- freebsd-ppc64 freebsd-s390 freebsd-s390x freebsd-sh3
- freebsd-sh3eb freebsd-sh4 freebsd-sh4eb freebsd-sparc
- kfreebsd-i386 kfreebsd-ia64 kfreebsd-alpha
- kfreebsd-amd64 kfreebsd-armeb kfreebsd-arm kfreebsd-hppa
- kfreebsd-m32r kfreebsd-m68k kfreebsd-mips
- kfreebsd-mipsel kfreebsd-powerpc kfreebsd-ppc64
- kfreebsd-s390 kfreebsd-s390x kfreebsd-sh3 kfreebsd-sh3eb
- kfreebsd-sh4 kfreebsd-sh4eb kfreebsd-sparc knetbsd-i386
- knetbsd-ia64 knetbsd-alpha knetbsd-amd64 knetbsd-armeb
- knetbsd-arm knetbsd-hppa knetbsd-m32r knetbsd-m68k
- knetbsd-mips knetbsd-mipsel knetbsd-powerpc
- knetbsd-ppc64 knetbsd-s390 knetbsd-s390x knetbsd-sh3
- knetbsd-sh3eb knetbsd-sh4 knetbsd-sh4eb knetbsd-sparc
- netbsd-i386 netbsd-ia64 netbsd-alpha netbsd-amd64
- netbsd-armeb netbsd-arm netbsd-hppa netbsd-m32r
- netbsd-m68k netbsd-mips netbsd-mipsel netbsd-powerpc
- netbsd-ppc64 netbsd-s390 netbsd-s390x netbsd-sh3
- netbsd-sh3eb netbsd-sh4 netbsd-sh4eb netbsd-sparc
- openbsd-i386 openbsd-ia64 openbsd-alpha openbsd-amd64
- openbsd-armeb openbsd-arm openbsd-hppa openbsd-m32r
- openbsd-m68k openbsd-mips openbsd-mipsel openbsd-powerpc
- openbsd-ppc64 openbsd-s390 openbsd-s390x openbsd-sh3
- openbsd-sh3eb openbsd-sh4 openbsd-sh4eb openbsd-sparc
- hurd-i386 hurd-ia64 hurd-alpha hurd-amd64 hurd-armeb
- hurd-arm hurd-hppa hurd-m32r hurd-m68k hurd-mips
- hurd-mipsel hurd-powerpc hurd-ppc64 hurd-s390 hurd-s390x
- hurd-sh3 hurd-sh3eb hurd-sh4 hurd-sh4eb hurd-sparc
- </p>
- </footnote>
+ string</em> in some place, it should select one of the strings
+ provided by <tt>dpkg-architecture -L</tt>. The strings are in
+ the format <tt><var>os</var>-<var>arch</var></tt>, though the OS
+ part is sometimes elided, as when the OS is Linux.
</p>
<p>
<tt><var>arch</var>-unknown-linux</tt>, since the
<tt>unknown</tt> does not look very good.
</p>
- </sect>
- <sect id="arch-wildcard-spec">
- <heading>Architecture Wildcards</heading>
+ <sect1 id="arch-wildcard-spec">
+ <heading>Architecture wildcards</heading>
- <p>
- A package may specify an architecture wildcard. Architecture
- wildcards are in the format <tt>any</tt> (which matches every
- architecture), <tt><var>os</var></tt>-any, or
- any-<tt><var>cpu</var></tt>. <footnote>
- Internally, the package system normalizes the GNU triplets and
- the Debian arches into Debian arch triplets (which are kind of
- inverted GNU triplets), with the first component of the
- triplet representing the libc and ABI in use. When matching
- two Debian arch triplets, whenever an <var>any</var> is found
- it matches with anything on the other side, like in:
- <example>
- gnu-linux-i386 is matched by gnu-linux-any
- gnu-kfreebsd-amd64 is matched by any-any-amd64
- </example>
- And, for example, <var>any</var> is normalized to
- <var>any-any-any</var>.
- </footnote>
- </p>
+ <p>
+ A package may specify an architecture wildcard. Architecture
+ wildcards are in the format <tt>any</tt> (which matches every
+ architecture), <tt><var>os</var></tt>-any, or
+ any-<tt><var>cpu</var></tt>. <footnote>
+ Internally, the package system normalizes the GNU triplets
+ and the Debian arches into Debian arch triplets (which are
+ kind of inverted GNU triplets), with the first component of
+ the triplet representing the libc and ABI in use, and then
+ does matching against those triplets. However, such
+ triplets are an internal implementation detail that should
+ not be used by packages directly. The libc and ABI portion
+ is handled internally by the package system based on
+ the <var>os</var> and <var>cpu</var>.
+ </footnote>
+ </p>
+ </sect1>
</sect>
<sect>
</p>
<p>
- The maintainer scripts are guaranteed to run with a
- controlling terminal and can interact with the user.
- See <ref id="controllingterminal">.
+ The maintainer scripts are not guaranteed to run with a
+ controlling terminal and may not be able to interact with
+ the user. See <ref id="controllingterminal">.
</p>
</item>
projects / debian / debian-policy.git / blobdiff