CONFMODULE(3) Library Functions Manual CONFMODULE(3)
NAME
confmodule - communicate with Debian configuration system FrontEnd.
SYNOPSIS
#!/bin/sh -e
. /usr/share/debconf/confmodule
db_version 2.0
db_capb 'backup'
CAPB=$RET
db_input 'foo/bar' || true
db_go || true
DESCRIPTION
This is a library of shell functions that eases communication with De-
bian's configuration management system. It can communicate with a Fron-
tEnd via the debconf protocol. The design is that each command in the
protocol is represented by one function in this module. The functionname
is the same as the command, except it is prefixed with "db_" and is
lower-case. Call the function and pass in any parameters you want to
follow the command. Any textual return code from the FrontEnd will be
returned to you in the $RET variable, while the numeric return code from
the FrontEnd will be returned as a return code (and so those return
codes must be captured or ignored).
NOTES
Once this library is loaded, any text you later output will go to stan-
dard error, rather than standard output. This is a good thing in gen-
eral, because text sent to standard output is interpreted by the Fron-
tEnd as commands. If you do want to send a command directly to the Fron-
tEnd, you must output it to file descriptor 3, like this:
echo GET foo/bar >&3
The library checks to make sure it is actually speaking to a FrontEnd by
examining the DEBIAN_HAS_FRONTEND variable. If it is set, a FrontEnd is
assumed to be running. If not, the library turns into one, and runs a
copy of the script that loaded the library connected to it. This means
that if you source this library, you should do so very near to the top
of your script, because everything before the sourcing of the library
may well be run again.
SEE ALSO
debconf-devel(7), dpkg-preconfigure(8), dpkg-reconfigure(8), deb-
conf_specification in the debian-policy package
AUTHOR
Joey Hess <joeyh@debian.org>
CONFMODULE(3)
Generated by dwww version 1.16 on Sat Oct 3 07:37:41 CEST 2026.