This file documents things you should know to write a new debhelper program.
+Any program with a name that begins with dh_ should conform to these
+guidelines (with the historical exception of dh_make).
Standardization:
---------------
Debhelper programs should never output anything to standard output except
error messages, important warnings, and the actual commands they run that
-modify files under debian/ and debian/tmp, etc (this last only if they are
-passed -v, and if you output the commands, you should indent them with 1 tab).
-This is so we don't have a lot of noise output when all the debhelper commands
-in a debian/rules are run, so the important stuff is clearly visible.
+modify files under debian/ (this last only if they are passed -v, and if you
+output the commands, you should indent them with 1 tab). This is so we don't
+have a lot of noise output when all the debhelper commands in a debian/rules
+are run, so the important stuff is clearly visible.
-Debhelper programs should accept the options, -v, -i, -a, -p, --no-act, and
--P, and any long forms of these options, like --verbose . If necessary, the
-options may be ignored.
+Debhelper programs should accept all options listed in the "SHARED
+DEBHELPER OPTIONS" section of debhelper(7), including any long forms of
+these options, like --verbose . If necessary, the options may be ignored.
If debhelper commands need config files, they should use
debian/package.filename as the name of the config file (replace filename
debian/control. Also, debhelper commands should accept the same sort of
information that appears in the config files, on their command lines, if
possible, and apply that information to the first package they act on.
+The config file format should be as simple as possible, generally just a
+list of files to act on.
Debhelper programs should never modify the debian/postinst, debian/prerm,
-etc scripts, instead, they can add lines to debian/postinst.debhelper, etc.
+etc scripts. Instead, they can add lines to debian/postinst.debhelper, etc.
The autoscript() function (see below) is one easy way to do this.
dh_installdeb is an exception, it will run after the other commands and
merge these modifications into the actual postinst scripts.
+In general, files named debian/*.debhelper are internal to debhelper, and
+their existence or use should not be relied on by external programs such as
+the build process of a package. These files will be deleted by dh_clean.
+
+Debhelper programs should default to doing exactly what policy says to do.
+
There are always exceptions. Just ask me.
-Introducing dh_lib:
+Introducing Dh_Lib:
------------------
-All debhelper programs use the dh_lib library (actually it's a shell script)
-to parse their arguments and set some useful variables. It's not mandatory
-that your program use dh_lib, but it will make it a lot easier to keep it in
-sync with the rest of debhelper if it does, so this is highly encouraged.
+Dh_Lib is the library used by all debhelper programs to parse their
+arguments and set some useful variables. It's not mandatory that your
+program use Dh_Lib.pm, but it will make it a lot easier to keep it in sync
+with the rest of debhelper if it does, so this is highly encouraged.
-Typically, you invoke dh_lib like this:
+Use Dh_Lib like this:
-PATH=debian:$PATH:/usr/lib/debhelper
-. dh_lib
+use Debian::Debhelper::Dh_Lib
+init();
-The path statement is there to make your program look first in debian/ for
-dh_lib (so users can install a modified version there if necessary), then the
-rest of the path, then the canonical location of dh_lib, /usr/lib/debhelper.
+The init() function causes Dh_lib to parse the command line and do some other
+initialization tasks.
Argument processing:
-------------------
All debhelper programs should respond to certain arguments, such as -v, -i,
--a, and -p. To help you make this work right, dh_lib handles argument
-processing.
+-a, and -p. To help you make this work right, Dh_Lib.pm handles argument
+processing. Just call init().
+
+You can add support for additional options to your command by passing an
+options hash to init(). The hash is then passed on the Getopt::Long to
+parse the command line options. For example, to add a --foo option, which
+sets $dh{FOO}:
-As soon as dh_lib loads, it processes any arguments that have been passed to
-your program. The following variables may be set during this stage; your
-program can use them later:
+init(options => { foo => \$dh{FOO} });
+
+After argument processing, some global variables are used to hold the
+results; programs can use them later. These variables are elements of the
+%dh hash.
switch variable description
--v DH_VERBOSE should the program verbosely output what it is
+-v VERBOSE should the program verbosely output what it is
doing?
---no-act DH_NO_ACT should the program not actually do anything?
--i,-a,-p DH_DOPACKAGES a space delimited list of the binary packages
- to act on
--i,-p DH_DOINDEP a space delimited list of the binary independent
- packages to act on
--a,-p DH_DOARCH a space delimited list of the binary dependent
- packages to act on
--n DH_NOSCRIPTS if set, do not make any modifications to the
+--no-act NO_ACT should the program not actually do anything?
+-i,-a,-p,-N DOPACKAGES a space delimited list of the binary packages
+ to act on (in Dh_Lib.pm, this is an array)
+-i DOINDEP set if we're acting on binary independent
+ packages
+-a DOARCH set if we're acting on binary dependent
+ packages
+-n NOSCRIPTS if set, do not make any modifications to the
package's postinst, postrm, etc scripts.
--X DH_EXCLUDE exclude a something from processing (you
+-o ONLYSCRIPTS if set, only make modifications to the
+ package's scripts, but don't look for or
+ install associated files.
+-X EXCLUDE exclude a something from processing (you
decide what this means for your program)
- DH_EXCLUDE_GREP same as DH_EXCLUDE, except all items are
- separated by '|' characters, instead of spaces,
- handy for egrep -v
--x DH_INCLUDE_CONFFILES
- include conffiles. It's -x for obscure
- historical reasons.
--d DH_D_FLAG you decide what this means to your program
--r DH_R_FLAG you decide what this means to your program
--k DH_K_FLAG you decide what this means to your program
--P DH_TMPDIR package build directory (implies only one
+ (This is an array)
+-X EXCLUDE_FIND same as EXCLUDE, except all items are put
+ into a string in a way that they will make
+ find find them. (Use ! in front to negate
+ that, of course) Note that this should
+ only be used inside complex_doit(), not in
+ doit().
+-d D_FLAG you decide what this means to your program
+-k K_FLAG used to turn on keeping of something
+-P TMPDIR package build directory (implies only one
package is being acted on)
--u DH_U_PARAMS will be set to a string, that is typically
+-u U_PARAMS will be set to a string, that is typically
parameters your program passes on to some
- other program.
--m DH_M_PARAMS will be set to a string, you decide what it
- means to your program
--V DH_V_FLAG will be set to a string, you decide what it
+ other program. (This is an array)
+-V V_FLAG will be set to a string, you decide what it
means to your program
--V DH_V_FLAG_SET will be 1 if -V was specified, even if no
+-V V_FLAG_SET will be 1 if -V was specified, even if no
parameters were passed along with the -V
--A DH_PARAMS_ALL generally means that additional command line
+-A PARAMS_ALL generally means that additional command line
parameters passed to the program (other than
those processed here), will apply to all
binary packages the program acts on, not just
the first
---init-script DH_INIT_SCRIPT will be set to a string, which specifies an
- init script name (probably only
- dh_installinit will ever use this)
+--priority PRIORITY will be set to a number
+--mainpackage MAINPACKAGE controls which package is treated as the
+ main package to act on
+--name NAME a name to use for installed files, instead of
+ the package name
+--error-handler ERROR_HANDLER a function to call on error
Any additional command line parameters that do not start with "-" will be
-ignored, and you can access them later just as you normally would ($1, $2,
-etc).
-
-If you need a new command line option, just ask me, and I will add it.
+ignored, and you can access them later just as you normally would.
Global variables:
----------------
-The following variables are also set, you can use any of them:
+The following keys are also set in the %dh hash when you call init():
MAINPACKAGE the name of the first binary package listed in
debian/control
-DH_FIRSTPACKAGE the first package we were instructed to act on. This package
- typically gets special treatment, additional arguments
+FIRSTPACKAGE the first package we were instructed to act on. This package
+ typically gets special treatment; additional arguments
specified on the command line may effect it.
Functions:
---------
-Dh_lib also contains a number of functions you may find useful.
-
-doit()
- Pass this function a string that is a shell command. It will run the
- command (unless DH_NO_ACT is set), and if DH_VERBOSE is set, it will
- also output the command to stdout. You should use this function for
- almost all commands your program performs that manipulate files in
- the package build directories.
-complex_doit()
- This is the same as doit(), except you can pass more complicated
- commands to it (ie, commands involving piping redirection)
-verbose_echo()
- Pass this command a string, and it will echo it if DH_VERBOSE is set.
-error()
+Dh_Lib.pm also contains a number of functions you may find useful.
+
+doit(@command)
+ Pass this function an array that is a
+ shell command. It will run the command (unless $dh{NO_ACT} is set), and
+ if $dh{VERBOSE} is set, it will also output the command to stdout. You
+ should use this function for almost all commands your program performs
+ that manipulate files in the package build directories.
+complex_doit($command)
+ Pass this function a string that is a shell command, it will run it
+ similarly to how doit() does. You can pass more complicated commands
+ to this (ie, commands involving piping redirection), however, you
+ have to worry about things like escaping shell metacharacters.
+verbose_print($message)
+ Pass this command a string, and it will echo it if $dh{VERBOSE} is set.
+error($errormsg)
Pass this command a string, it will output it to standard error and
exit.
-warning()
+warning($message)
Pass this command a string, and it will output it to standard error
as a warning message.
-tmpdir()
+tmpdir($dir)
Pass this command the name of a binary package, it will return the
name of the tmp directory that will be used as this package's
- package build directory. Typically, this will be "debian/tmp" or
- "debian/package".
-pkgfile()
+ package build directory. Typically, this will be "debian/package".
+compat($num)
+ Pass this command a number, and if the current compatibility level
+ is less than or equal to that number, it will return true.
+ Looks at DH_COMPAT to get the compatibility level.
+pkgfile($package, $basename)
Pass this command the name of a binary package, and the base name of a
file, and it will return the actual filename to use. This is used
for allowing debhelper programs to have configuration files in the
debian/ directory, so there can be one config file per binary
package. The convention is that the files are named
debian/package.filename, and debian/filename is also allowable for
- the MAINPACKAGE. If the file does not exist, nothing is returned.
-pkgext()
+ the $dh{MAINPACKAGE}. If the file does not exist, nothing is returned.
+pkgext($package)
Pass this command the name of a binary package, and it will return
the name to prefix to files in debian/ for this package. For the
- MAINPACKAGE, it returns nothing (there is no prefix), for the other
+ $dh{MAINPACKAGE}, it returns nothing (there is no prefix), for the other
packages, it returns "package.".
-isnative()
+isnative($package)
Pass this command the name of a package, it returns 1 if the package
is a native debian package.
- As a side effect, VERSION is set to the version number of the
+ As a side effect, $dh{VERSION} is set to the version number of the
package.
-autoscript()
- Pass 3 parameters:
- 1: script to add to
- 2: filename of snippet
- 3: sed commands to run on the snippet. Ie, s/#PACKAGE#/$PACKAGE/
- (optional)
+autoscript($package, $scriptname, $snippetname, $sedcommands || $sub)
+ Pass parameters:
+ - binary package to be affected
+ - script to add to
+ - filename of snippet
+ - (optional) EITHER sed commands to run on the snippet. Ie,
+ s/#PACKAGE#/$PACKAGE/ Note: Passed to the shell inside double
+ quotes.
+ OR a perl sub to invoke with $_ set to each line of the snippet in
+ turn.
This command automatically adds shell script snippets to a debian
maintainer script (like the postinst or prerm).
+ Note that in v6 mode and up, the snippets are added in reverse
+ order for the removal scripts.
+dirname($pathname)
+ Return directory part of pathname.
+basename($pathname)
+ Return base of pathname,
+addsubstvar($package, $substvar, $deppackage, $verinfo, $remove)
+ This function adds a dependency on some package to the specified
+ substvar in a package's substvar's file. It needs all these
+ parameters:
+ - binary package that gets the item
+ - name of the substvar to add the item to
+ - the package that will be depended on
+ - version info for the package (optional) (ie: ">= 1.1")
+ - if this last parameter is passed, the thing that would be added
+ is removed instead. This can be useful to ensure that a debhelper
+ command is idempotent. (However, we generally don't bother,
+ and rely on the user calling dh_prep.) Note that without this
+ parameter, if you call the function twice with the same values it
+ will only add one item to the substvars file.
+delsubstvar($package, $substvar)
+ This function removes the entire line for the substvar from the
+ package's shlibs file.
+excludefile($filename)
+ This function returns true if -X has been used to ask for the file
+ to be excluded.
+is_udeb($package)
+ Returns true if the package is marked as a udeb in the control
+ file.
+udeb_filename($package)
+ Returns the filename of the udeb package.
+getpackages($type)
+ Returns a list of packages in the control file.
+ Pass "arch" or "indep" to specify arch-dependent or
+ -independent. If nothing is specified, returns all
+ packages (including packages that are not built
+ for this architecture). Pass "both" to get the union
+ of "arch" and "indep" packages.
+ As a side effect, populates %package_arches and %package_types with
+ the types of all packages (not only those returned).
+inhibit_log()
+ Prevent logging the program's successful finish to
+ debian/*debhelper.log
+load_log($package, $hashref)
+ Loads the log file for the given package and returns a list of
+ logged commands.
+ (Passing a hashref also causes it to populate the hash.)
+write_log($cmd, $package ...)
+ Writes the log files for the specified package(s), adding
+ the cmd to the end.
+
+Sequence Addons:
+---------------
+
+The dh(1) command has a --with <addon> parameter that ca be used to load
+a sequence addon module named Debian::Debhelper::Sequence::<addon>.
+These modules can add/remove commands to the dh command sequences, by
+calling some functions from Dh_Lib:
+
+insert_before($existing_command, $new_command)
+ Insert $new_command in sequences before $existing_command
+
+insert_after($existing_command, $new_command)
+ Insert $new_command in sequences after $existing_command
+
+remove_command($existing_command)
+ Remove $existing_command from the list of commands to run
+ in all sequences.
+
+add_command($new_command, $sequence)
+ Add $new_command to the beginning of the specified sequence.
+ If the sequence does not exist, it will be created.
+
+add_command_options($command, $opt1, $opt2, ...)
+ Append $opt1, $opt2 etc. to the list of additional options which
+ dh passes when running the specified $command. These options are
+ not relayed to debhelper commands called via $command override.
+
+remove_command_options($command)
+ Clear all additional $command options previously added with
+ add_command_options().
+
+remove_command_options($command, $opt1, $opt2, ...)
+ Remove $opt1, $opt2 etc. from the list of additional options which
+ dh passes when running the specified $command.
+
+Buildsystem Classes:
+-------------------
+
+The dh_auto_* commands are frontends that use debhelper buildsystem
+classes. These classes have names like Debian::Debhelper::Buildsystem::foo,
+and are derived from Debian::Debhelper::Buildsystem, or other, related
+classes.
-Notes:
------
+A buildsystem class needs to inherit or define these methods: DESCRIPTION,
+check_auto_buildable, configure, build, test, install, clean. See the comments
+inside Debian::Debhelper::Buildsystem for details. Note that this interface
+is still subject to change.
-Dh_lib is still evolving.
-There will probably be a perl version too, in the future.
+Note that third-party buildsystems will not automatically be used by default,
+but can be forced to be used via the --buildsystem parameter.
--- Joey Hess <joeyh@master.debian.org>
+-- Joey Hess <joeyh@debian.org>
projects / debhelper.git / blobdiff