Initial import of pkg_alternatives, version 1.0:

pkg_alternatives is a tool to manage the alternatives system provided by
The NetBSD Packages Collection, also known as pkgsrc.  It creates, configures
and destroys generic wrappers used to run programs with similar interfaces.

No objections in tech-pkg@.  Agreed with jlam@, who has provided lots of
design suggestions.

7 files changed, 1103 insertions, 0 deletions

diff --git a/pkgtools/pkg_alternatives/DESCR b/pkgtools/pkg_alternatives/DESCR
new file mode 100644
index 00000000000..d2c7236144e
--- /dev/null
+++ b/pkgtools/pkg_alternatives/DESCR
@@ -0,0 +1,3 @@
+pkg_alternatives is a tool to manage the alternatives system provided by
+The NetBSD Packages Collection, also known as pkgsrc.  It creates, configures
+and destroys generic wrappers used to run programs with similar interfaces.
diff --git a/pkgtools/pkg_alternatives/Makefile b/pkgtools/pkg_alternatives/Makefile
new file mode 100644
index 00000000000..3a3d33afa03
--- /dev/null
+++ b/pkgtools/pkg_alternatives/Makefile
@@ -0,0 +1,57 @@
+# $NetBSD: Makefile,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+#
+
+DISTNAME=	pkg_alternatives-1.0
+CATEGORIES=	pkgtools
+MASTER_SITES=	# empty
+DISTFILES=	# empty
+
+MAINTAINER=	jmmv@NetBSD.org
+COMMENT=	Generic wrappers for programs with similar interfaces
+
+PKG_INSTALLATION_TYPES=	overwrite pkgviews
+
+EXTRACT_ONLY=		# empty
+NO_CHECKSUM=		YES
+NO_BUILD=		YES
+NO_BUILDLINK=		YES
+USE_PKGINSTALL=		YES
+WRKSRC=			${WRKDIR}
+
+DATADIR=		${PREFIX}/share/pkg_alternatives
+DBDIR=			${PREFIX}/libdata/pkg_alternatives
+
+MAKE_DIRS=		${DBDIR}
+MAKE_DIRS+=		${PKG_SYSCONFDIR}
+
+PKG_SYSCONFSUBDIR=	pkg_alternatives
+
+SUBST_CLASSES+=		vars
+SUBST_STAGE.vars=	do-configure
+SUBST_MESSAGE.vars=	"Configuring sources."
+SUBST_FILES.vars=	${WRKSRC}/*
+SUBST_SED.vars=		-e 's|@CONFDIR@|${PKG_SYSCONFDIR}|g'
+SUBST_SED.vars+=	-e 's|@DATADIR@|${DATADIR}|g'
+SUBST_SED.vars+=	-e 's|@DBDIR@|${DBDIR}|g'
+SUBST_SED.vars+=	-e 's|@PKG_DBDIR@|${PKG_DBDIR}|g'
+SUBST_SED.vars+=	-e 's|@PREFIX@|${PREFIX}|g'
+SUBST_SED.vars+=	-e 's|@ROOT_USER@|${ROOT_USER}|g'
+SUBST_SED.vars+=	-e 's|@SH@|${SH}|g'
+
+INSTALLATION_DIRS=	man/man8 sbin
+
+do-extract:
+	${CP} ${FILESDIR}/pkg_alternatives.sh ${WRKSRC}
+	${CP} ${FILESDIR}/pkg_alternatives.8 ${WRKSRC}
+	${CP} ${FILESDIR}/wrapper.sh ${WRKSRC}
+	${CP} ${FILESDIR}/wrapper.man ${WRKSRC}
+
+do-install:
+	${INSTALL_SCRIPT} ${WRKSRC}/pkg_alternatives.sh \
+		${PREFIX}/sbin/pkg_alternatives
+	${INSTALL_MAN} ${WRKSRC}/pkg_alternatives.8 ${PREFIX}/man/man8/
+	${INSTALL_DATA_DIR} ${DATADIR}
+	${INSTALL_DATA} ${WRKSRC}/wrapper.sh ${DATADIR}/
+	${INSTALL_DATA} ${WRKSRC}/wrapper.man ${DATADIR}/
+
+.include "../../mk/bsd.pkg.mk"
diff --git a/pkgtools/pkg_alternatives/PLIST b/pkgtools/pkg_alternatives/PLIST
new file mode 100644
index 00000000000..0516798c587
--- /dev/null
+++ b/pkgtools/pkg_alternatives/PLIST
@@ -0,0 +1,6 @@
+@comment $NetBSD: PLIST,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+man/man8/pkg_alternatives.8
+share/pkg_alternatives/wrapper.man
+share/pkg_alternatives/wrapper.sh
+sbin/pkg_alternatives
+@dirrm share/pkg_alternatives
diff --git a/pkgtools/pkg_alternatives/files/pkg_alternatives.8 b/pkgtools/pkg_alternatives/files/pkg_alternatives.8
new file mode 100644
index 00000000000..3e990da236c
--- /dev/null
+++ b/pkgtools/pkg_alternatives/files/pkg_alternatives.8
@@ -0,0 +1,289 @@
+.\" $NetBSD: pkg_alternatives.8,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+.\"
+.\" pkg_alternatives - Generic wrappers for programs with similar interfaces
+.\" Copyright (c) 2005 Julio M. Merino Vidal <jmmv@NetBSD.org>
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Neither the name of The NetBSD Foundation nor the names of its
+.\"    contributors may be used to endorse or promote products derived
+.\"    from this software without specific prior written permission.
+.\" 3. Neither the name of author nor the names of its contributors may
+.\"    be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd January 25, 2005
+.Dt ALTERNATIVES 8
+.Os
+.Sh NAME
+.Nm pkg_alternatives
+.Nd generic wrappers for programs with similar interfaces
+.Sh SYNOPSIS
+.Nm
+.Op Fl sw
+.Op Fl p Ar prefix
+action
+.Ar arg1 ... argN
+.Sh DESCRIPTION
+.Nm
+is a tool to manage the
+.Em alternatives system
+provided by The NetBSD Packages Collection, also known as pkgsrc.
+It creates, configures and destroys generic wrappers used to run programs
+with similar interfaces.
+.Pp
+Consider, for example, the
+.Xr vi 1
+editor.
+Both
+.Xr nvi 1
+and
+.Xr vim 1
+provide very similar functionality, although neither of them is named
+.Sq vi .
+In this situation, it may be useful to have a
+.Em wrapper
+in place of the generic name which points to one of the multiple
+.Em alternatives
+available.
+.Pp
+The alternatives are classified according to the
+.Em package
+they belong to.
+In other words, a concrete package contains a list of all the wrappers it
+affects by providing alternatives to them.
+This makes things easier to the end user and/or the administrator who has
+to deal with them, as they can manually select a package rather than a
+bunch of wrappers.
+.Pp
+Wrappers are identified by its file name relative to the installation
+prefix, i.e.,
+.Pa @PREFIX@
+if the
+.Fl p
+option is not used.
+In the example above, the wrapper could be identified by the
+.Pa bin/vi
+string.
+The identifier is the string used as the
+.Sq wrapper
+argument in all the actions that require it.
+.Pp
+The generic wrapper scans a list of available alternatives and tries to
+execute them in order; the first one that succeeds is the one used for
+that run.
+This list of alternatives is read from multiple configuration files.
+Each one contains a list of possible alternatives, one per line, with
+optional arguments to them.
+Lines starting with
+.Sq #
+are considered comments and are ignored.
+.Pp
+The following configuration files are read, in strict order, for each
+wrapper (replace the
+.Sq wrapper
+word with the wrapper's absolute file name):
+.Bl -tag -width XXXX
+.It ~/.alternatives/wrapper
+This is called the
+.Em user configuration file
+and is only read when not running as
+.Sq @ROOT_USER@ .
+Otherwise, tools such as
+.Xr sudo 8
+could be used to execute any program in the system.
+This file can be freely edited by the user, either by hand or by using
+the
+.Sq manual
+action described below.
+.It @CONFDIR@/wrapper
+This is called the
+.Em system configuration file
+and is read if found.
+This file can be freely edited by the administrator, either by hand or
+by using the
+.Sq manual
+action described below.
+.It @DATADIR@/wrapper
+This is called the
+.Em database configuration file
+and is always read.
+This file must not be edited by hand; packages providing alternatives
+will take care to (un)register themselves from them when (de)installed.
+.El
+.Ss Options
+The following options are available:
+.Bl -tag -width XpXprefixX
+.It Fl p Ar prefix
+Set installation prefix.
+This affects where wrappers and their manual pages are looked for.
+The prefix defaults to
+.Pa @PREFIX@
+if this flag is not given.
+.It Fl s
+Run in silent mode: no output except for errors.
+.It Fl w
+Operate on wrappers rather than on packages.
+This affects the behavior of all actions.
+.El
+.Ss Actions in package mode
+The following table describes each available action and its behavior when
+working in package mode.
+All these actions are at a higher level than the same actions in wrapper
+mode.
+They always end up using the later at some point, so you should also
+read the next section to be aware of the exact effect of each the command.
+.Bl -tag -width XXXX
+.It auto Ar package
+Removes any manual configuration from each wrapper associated to the given
+package.
+This means that all the affected wrappers are then free to choose whichever
+alternative they prefer.
+.It list
+Lists which of the installed packages provide alternatives.
+Any of the packages shown by this command can then be fed back to the
+.Sq auto
+and
+.Sq manual
+actions.
+.It manual Ar package
+Manually selects all the alternatives that belong to
+.Ar package
+to be the default for their respective wrappers.
+.It rebuild
+Rebuilds the alternatives database, found in
+.Pa @DBDIR@ ,
+based on the contents of the package database, usually available in
+.Pa @PKG_DBDIR@ .
+Basically, it scans the later looking for packages with an
+.Pa +ALTERNATIVES
+file in them, and, for each of those, the
+.Sq register
+action is called with the appropriate file name.
+.It register Ar package wrapper alternative arguments
+Registers a new
+.Ar alternative
+for the given
+.Ar wrapper
+in the specified
+.Ar package .
+If the package does not exist in the database, it is created.
+.Pp
+This action must not be used directly; packages providing alternatives
+will take care to execute it at installation time.
+.It status Ar package
+For each wrapper that belongs to
+.Ar package ,
+shows which alternative will be used by it in the next run.
+It also displays all available candidates for each of them.
+.It unregister Ar package
+Removes the
+.Ar package
+from the database.
+All alternatives associated to it are also removed.
+.Pp
+This action must not be used directly; packages providing alternatives
+will take care to execute it at deinstallation time.
+.El
+.Ss Actions in wrapper mode
+The following table describes each available action and its behavior when
+working in wrapper mode.
+Note that these actions work at a very low level as they are used to manage
+wrappers and alternative commands directly.
+In most situations, you will want to use these actions in package mode.
+.Bl -tag -width XXXX
+.It auto Ar wrapper
+Removes any manual configuration created for the given
+.Ar wrapper .
+That is, if running as
+.Sq @ROOT_USER@ ,
+the system configuration file is deleted; otherwise, the user configuration
+file is removed.
+The effect of this action is that the wrapper is then free to choose any
+alternative it wants.
+.It manual Ar wrapper alternative arguments
+Manually selects the
+.Ar alternative
+for the given
+.Ar wrapper .
+If running as
+.Sq @ROOT_USER@ ,
+the system configuration file is modified; otherwise, the user configuration
+file is changed.
+The effect of this action is that the wrapper will try to use your preferred
+alternatives, regardless of what is installed on the system.
+.It register Ar wrapper alternative arguments
+Registers a new
+.Ar alternative
+for the given
+.Ar wrapper .
+If the wrapper did not exist before, it is created.
+You may optionally pass several
+.Ar arguments
+to the
+.Ar alternative
+program.
+.Pp
+This action should not be used directly; packages providing alternatives
+will take care to execute it at installation time.
+.It status Ar wrapper
+Shows which alternative will be used by the
+.Ar wrapper
+in the next run.
+It also displays all available candidates for it.
+.It unregister Ar wrapper alternative
+Removes the
+.Ar alternative
+from the given
+.Ar wrapper .
+If there are no more alternatives available, the wrapper is removed.
+.Pp
+This action should not be used directly; packages providing alternatives
+will take care to execute it at deinstallation time.
+.El
+.Sh ENVIRONMENT
+.Bl -tag -width PKG_DBDIR
+.It Ev PKG_DBDIR
+Location of the package database directory.
+Defaults to
+.Pa @PKG_DBDIR@ .
+.El
+.Sh FILES
+.Bl -tag -width XXXX
+.It Pa ~/.pkg_alternatives/
+User-specific configuration directory.
+.It Pa @CONFDIR@/
+System-wide configuration directory.
+.It Pa @DATADIR@/
+System-wide configuration database.
+.El
+.Sh DIAGNOSTICS
+.Nm
+exists 0 on success and 1 if an error occurred.
+.Sh SEE ALSO
+.Xr pkg_add 1 ,
+.Xr pkg_delete 1
+.Sh HISTORY
+The
+.Nm
+utility first appeared in pkgsrc-2005Q1.
+.Pp
+This utility was inspired by the alternatives system found in the Debian
+operating system.
+.Sh AUTHORS
+.An Julio M. Merino Vidal Aq jmmv@NetBSD.org
diff --git a/pkgtools/pkg_alternatives/files/pkg_alternatives.sh b/pkgtools/pkg_alternatives/files/pkg_alternatives.sh
new file mode 100644
index 00000000000..86cd6d23e63
--- /dev/null
+++ b/pkgtools/pkg_alternatives/files/pkg_alternatives.sh
@@ -0,0 +1,614 @@
+#!@SH@
+#
+# $NetBSD: pkg_alternatives.sh,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+#
+# pkg_alternatives - Generic wrappers for programs with similar interfaces
+# Copyright (c) 2005 Julio M. Merino Vidal <jmmv@NetBSD.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name of author nor the names of its contributors may
+#    be used to endorse or promote products derived from this software
+#    without alternative prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+Conf_Dir=@CONFDIR@@PREFIX@
+Data_Dir=@DATADIR@
+Db_Dir=@DBDIR@@PREFIX@
+Prefix=@PREFIX@
+Prog_Name=${0##*/}
+Verbose=yes
+
+: ${PKG_DBDIR:=@PKG_DBDIR@}
+
+# -------------------------------------------------------------------------
+
+# action_auto_package package
+#
+# Configures the given package to be in automatic mode.  I.e., it removes
+# local customizations for all related wrappers, so that only the files in
+# the database are taken into account.
+#
+action_auto_package() {
+    validate_args auto ${#} -eq 1
+    validate_package ${1}
+    pkg=${PKG_DBDIR}/${1}*/+ALTERNATIVES
+
+    set -- $(cat ${pkg} | tr ' ' '¬')
+    while [ ${#} -gt 0 ]; do
+        action_auto_wrapper $(echo ${1} | cut -d '¬' -f 1)
+        shift
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_auto_wrapper wrapper
+#
+# Configures the given wrapper to be in automatic mode.  I.e., it removes
+# local customizations so that only the files in the database are taken
+# into account.
+#
+# wrapper is a path relative to prefix.
+#
+action_auto_wrapper() {
+    validate_args auto ${#} -eq 1
+    validate_wrapper ${1} yes
+
+    conf=$(get_my_config)/${1}
+    if [ -f ${conf} ]; then
+        info "removing configuration from \`${conf}'"
+        rm -f ${conf}
+        rmdir_p ${conf%/*}
+    else
+        info "no existing configuration for \`${1}'; nothing to be done"
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# action_list_package
+#
+# Lists all available packages that provide alternatives.
+#
+action_list_package() {
+    validate_args list ${#} -eq 0
+
+    info "looking for alternatives in \`${PKG_DBDIR}'"
+    for d in ${PKG_DBDIR}/*; do
+        [ -f ${d}/+ALTERNATIVES ] && echo ${d##${PKG_DBDIR}/}
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_list_wrapper
+#
+# Unavailable action.
+#
+action_list_wrapper() {
+    err "the \`list' action cannot be used in wrapper mode"
+}
+
+# -------------------------------------------------------------------------
+
+# action_manual_package package
+#
+# Configures the given package to be the preferred alternative for all the
+# wrappers associated to it.
+#
+action_manual_package() {
+    validate_args manual ${#} -eq 1
+    validate_package ${1}
+    pkg=${PKG_DBDIR}/${1}*/+ALTERNATIVES
+
+    set -- $(cat ${pkg} | tr ' ' '¬')
+    while [ ${#} -gt 0 ]; do
+        action_manual_wrapper $(echo ${1} | tr '¬' ' ')
+        shift
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_manual_wrapper wrapper alternative arguments
+#
+# Configures the given wrapper to use the specified alternative.
+# If running as the administrator, the system-wide settings are changed;
+# otherwise, the user-specific settings are affected.
+#
+# wrapper is a path relative to prefix.
+# alternative is an absolute path.
+#
+action_manual_wrapper() {
+    validate_args manual ${#} -ge 2
+    validate_wrapper ${1} yes
+    validate_alternative ${2}
+
+    conf=$(get_my_config)/${1}
+    info "modifying configuration from \`${conf}'"
+    mkdir_p ${conf%/*}
+    shift
+    echo "${*}" >${conf}
+}
+
+# -------------------------------------------------------------------------
+
+# action_rebuild_package
+#
+# Rebuilds the alternatives database from the package database.
+#
+action_rebuild_package() {
+    validate_args list ${#} -eq 0
+
+    info "removing contents of \`@DBDIR@'"
+    rm -rf @DBDIR@/* 2>/dev/null
+    info "looking for alternatives in \`${PKG_DBDIR}'"
+    for d in ${PKG_DBDIR}/*; do
+        if [ -f ${d}/+ALTERNATIVES ]; then
+            action_register_package ${d}/+ALTERNATIVES
+        fi
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_rebuild_wrapper
+#
+# Unavailable action.
+#
+action_rebuild_wrapper() {
+    err "the \`rebuild' action cannot be used in wrapper mode"
+}
+
+# -------------------------------------------------------------------------
+
+# action_register_package file
+#
+# Registers all wrapper/alternative pairs listed in the file.  This is
+# supposed to be an +ALTERNATIVES file found inside a package in PKG_DBDIR.
+# Each line should follow the semantics expected by action_register_wrapper.
+#
+action_register_package() {
+    validate_args register ${#} -eq 1
+
+    set -- $(cat ${1} | tr ' ' '¬')
+    while [ ${#} -gt 0 ]; do
+        action_register_wrapper $(echo ${1} | tr '¬' ' ')
+        shift
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_register_wrapper wrapper alternative arguments
+#
+# Registers a new alternative for the given wrapper in the database.
+# The wrapper and its manual page are created if they do not exist.
+#
+action_register_wrapper() {
+    validate_args register ${#} -ge 2
+    validate_wrapper ${1} no
+    validate_alternative ${2}
+
+    wbase=${1}; shift
+    alt=${1}; shift
+    args=${*}
+
+    wabs=${Prefix}/${wbase}
+    manpage=$(get_manpage ${wbase})
+    dbconf=${Db_Dir}/${wbase}
+    sysconf=${Conf_Dir}/${wbase}
+
+    if [ ! -f ${dbconf} ]; then
+        info "initializing database entry for \`${wbase}'"
+        mkdir_p ${dbconf%/*}
+        touch ${dbconf%/*}
+    fi
+    info "registering alternative \`${alt}' for wrapper \`${wbase}'"
+    if [ -n "${args}" ]; then
+        echo "${alt} ${args}" >>${dbconf}
+    else
+        echo "${alt}" >>${dbconf}
+    fi
+
+    if [ ! -f ${wabs} ]; then
+        info "creating wrapper \`${wbase}'"
+        mkdir_p ${wabs%/*}
+        sed -e "s|__SH__|@SH@|g" \
+            -e "s|__CONF_FILE__|${sysconf}|g" \
+            -e "s|__CREATOR__|${Prog_Name}|g" \
+            -e "s|__DB_FILE__|${dbconf}|g" \
+            -e "s|__ROOT_USER__|@ROOT_USER@|g" \
+            -e "s|__WRAPPER__|${wabs}|g" \
+            <${Data_Dir}/wrapper.sh >${wabs}
+        chmod +x ${wabs}
+        mkdir_p ${manpage%/*}
+        sed -e "s|__CONF_FILE__|${sysconf}|g" \
+            -e "s|__CREATOR__|${Prog_Name}|g" \
+            -e "s|__DB_FILE__|${dbconf}|g" \
+            -e "s|__PREFIX__|${Prefix}|g" \
+            -e "s|__SECTION__|$(get_manpage_sect ${wbase})|g" \
+            -e "s|__TITLE__|$(echo ${wbase##*/} | tr a-z A-Z)|g" \
+            -e "s|__WRAPPER__|${wbase##*/}|g" \
+            -e "s|__WRAPPERBASE__|${wbase}|g" \
+            <${Data_Dir}/wrapper.man >${manpage}
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# action_status_package package
+#
+# Shows the status of each wrapper associated to the given package.
+#
+action_status_package() {
+    validate_args status ${#} -eq 1
+    validate_package ${1}
+    pkg=${PKG_DBDIR}/${1}*/+ALTERNATIVES
+
+    set -- $(cat ${pkg} | tr ' ' '¬')
+    while [ ${#} -gt 0 ]; do
+        action_status_wrapper $(echo ${1} | cut -d '¬' -f 1)
+        shift
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_status_wrapper wrapper
+#
+# Shows the current status for the given wrapper.
+#
+action_status_wrapper() {
+    validate_args status ${#} -eq 1
+    validate_wrapper ${1} yes
+
+    wbase=${1}
+    dbconf=${Db_Dir}/${wbase}
+    sysconf=${Conf_Dir}/${wbase}
+    userconf=~/.pkg_alternatives${Prefix}/${wbase}
+
+    [ $(id -un) = @ROOT_USER@ ] && userconf=
+    alts=$(cat ${userconf} ${sysconf} ${dbconf} 2>/dev/null | grep -v '^#' | \
+           tr ' ' '¬')
+
+    found=
+    for a in ${alts}; do
+        prog=$(echo ${a} | cut -d '¬' -f 1)
+        if [ -x ${prog} ]; then
+            found=$(echo ${a} | tr '¬' ' ')
+            break
+        fi
+    done
+
+    [ -n "${found}" ] ||
+        err "the wrapper \`${wbase}' exists but has no valid alternatives"
+
+    echo "\`${wbase}' points to \`${found}'"
+    for a in $(echo ${alts} | tr ' ' '\n' | sort | uniq); do
+        echo "    candidate: $(echo ${a} | tr '¬' ' ')"
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_unregister_package file
+#
+# Unregisters the given package (given by its +ALTERNATIVES file) and
+# removes all associated alternatives from their respective wrappers.
+#
+action_unregister_package() {
+    validate_args unregister ${#} -eq 1
+
+    set -- $(cat ${1} | tr ' ' '¬')
+    while [ ${#} -gt 0 ]; do
+        action_unregister_wrapper $(echo ${1} | tr '¬' ' ')
+        shift
+    done
+}
+
+# -------------------------------------------------------------------------
+
+# action_unregister_wrapper wrapper alternative arguments
+#
+# Unregisters an alternative for the given wrapper.  The lookup is done
+# based on the alternative name and its arguments.  I.e., there must be
+# an exact match.  If no alternatives remain after the removal, the wrapper
+# and its manpage are removed.
+#
+action_unregister_wrapper() {
+    validate_args unregister ${#} -ge 2
+    validate_wrapper ${1} yes
+
+    wbase=${1}; shift
+    alt=${1}; shift
+    args=${*}
+
+    manpage=$(get_manpage ${wbase})
+    dbconf=${Db_Dir}/${wbase}
+
+    if [ -n "${args}" ]; then
+        grep -v "^${alt} ${args}$" <${dbconf} >${dbconf}.new
+    else
+        grep -v "^${alt}$" <${dbconf} >${dbconf}.new
+    fi
+    if cmp -s ${dbconf} ${dbconf}.new; then
+        rm -f ${dbconf}.new
+        err "unknown alternative \`${alt}' for wrapper \`${wbase}'"
+    fi
+    mv ${dbconf}.new ${dbconf}
+
+    if ! grep '^/' ${dbconf} >/dev/null; then
+        info "no more alternatives for \`${wbase}'; removing"
+        rm -f ${dbconf} ${Prefix}/${wbase} ${manpage}
+        rmdir_p ${dbconf%/*}
+        rmdir_p ${Prefix}/${wbase%/*}
+        rmdir_p ${manpage%/*}
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# err message
+#
+# Prints the given error message and exist with an error code.
+#
+err() {
+    echo "${Prog_Name}: ${*}" 1>&2
+    exit 1
+}
+
+# -------------------------------------------------------------------------
+
+# get_my_config
+#
+# Prints the configuration directory for the current user.  If root, this
+# is the system-wide configuration directory.  Otherwise, it is the user's
+# personal directory.
+#
+get_my_config() {
+    if [ $(id -un) = @ROOT_USER@ ]; then
+        echo ${Conf_Dir}
+    else
+        echo ~/.pkg_alternatives${Prefix}
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# get_manpage wrapper
+#
+# Prints the absolute path to the manual page associated to wrapper.
+# Does no error checking; validate_wrapper has to be called before this
+# function to ensure wrapper is a valid name.
+#
+get_manpage() {
+    sect=$(get_manpage_sect ${1})
+    echo ${Prefix}/man/man${sect}/${1##*/}.${sect}
+}
+
+# -------------------------------------------------------------------------
+
+# get_manpage_sect wrapper
+#
+# Prints the section number that will be used by the wrapper's manpage.
+# Does no error checking; validate_wrapper has to be called before this
+# function to ensure wrapper is a valid name.
+#
+get_manpage_sect() {
+    case ${1%/*} in
+        bin) echo 1 ;;
+        libexec|sbin) echo 8 ;;
+    esac
+}
+
+# -------------------------------------------------------------------------
+
+# info message
+#
+# Prints the given informative message if running in verbose mode.
+#
+info() {
+    [ ${Verbose} = yes ] && echo "${Prog_Name}: ${*}"
+}
+
+# -------------------------------------------------------------------------
+
+# mkdir_p directory
+#
+mkdir_p() {
+    if [ ! -d ${1} ]; then
+        cnt=2
+        max=$(($(echo ${1} | tr '/' ' ' | wc -w | awk '{ print $1; }') + 1))
+        while [ ${cnt} -le ${max} ]; do
+            mkdir $(echo ${1} | cut -d '/' -f -${cnt}) 2>/dev/null
+            cnt=$((${cnt} + 1))
+        done
+        [ -d ${1} ] || err "cannot create directory \`${1}'"
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# usage
+#
+# Shows an usage message and exits the program with an error condition.
+#
+usage() {
+    echo "Usage: ${Prog_Name} [-sw] [-p prefix] action [arg1 ... argN]" 1>&2
+    exit 1
+}
+
+# -------------------------------------------------------------------------
+
+# rmdir_p directory
+#
+rmdir_p() {
+    if [ -d ${1} ]; then
+        cnt=$(($(echo ${1} | tr '/' ' ' | wc -w | awk '{ print $1; }') + 1))
+        while [ ${cnt} -gt 1 ]; do
+            rmdir $(echo ${1} | cut -d '/' -f -${cnt}) 2>/dev/null
+            cnt=$((${cnt} - 1))
+        done
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# validate_alternative name
+#
+# Verifies that the given program name is valid to be used as an
+# alternative.
+#
+validate_alternative() {
+    echo ${1} | grep '^/' >/dev/null || \
+        err "the alternative \`${1}' is not an absolute file name"
+    [ -x ${1} ] || \
+        err "the alternative \`${1}' is not an executable"
+}
+
+# -------------------------------------------------------------------------
+
+# validate_args action argcount operator expected
+#
+# Verifies that the number of arguments passed to the specified action
+# are correct according to its semantics.  Prints an error message if
+# incorrect.
+#
+validate_args() {
+    [ ${2} ${3} ${4} ] || \
+        err "incorrect number of arguments for the \`${1}' action"
+}
+
+# -------------------------------------------------------------------------
+
+# validate_package name
+#
+# Verifies that the specified package is valid.
+#
+validate_package() {
+    if [ ! -f ${PKG_DBDIR}/${1}/+ALTERNATIVES ]; then
+        cnt=$(cd ${PKG_DBDIR} && ls -d ${1}-[0-9]* 2>/dev/null | wc -l | \
+              awk '{ print $1; }')
+        if [ "${cnt}" -eq 0 ]; then
+            err "the package \`${1}' is not known"
+        elif [ "${cnt}" -gt 1 ]; then
+            err "multiple matches found for \`${1}'"
+        fi
+
+        # Reached this point, there is a single match for the package,
+        # but it may still be wrong (i.e., no alternatives for it).
+        [ ! -f ${PKG_DBDIR}/${1}*/+ALTERNATIVES ] && \
+            err "no alternatives defined for the \`${1}' package"
+    fi
+}
+
+# -------------------------------------------------------------------------
+
+# validate_wrapper name exists
+#
+# Verifies that the specified wrapper is valid, i.e., if it belongs to a
+# known directory.  Also, if the exists parameter is yes, the function
+# ensures that the wrapper already exists (as well as its configuration
+# file in the database).
+#
+validate_wrapper() {
+    case ${1%/*} in
+        bin|libexec|sbin)
+            if [ ${2} = yes ]; then
+                [ -x ${Prefix}/${1} ] || \
+                    err "the wrapper \`${1}' does not exist or is not" \
+                        "executable"
+                [ -f ${Db_Dir}/${1} ] || \
+                    err "the database configuration \`${Db_Dir}/${1}'" \
+                        "does not exist"
+            fi
+            ;;
+        *)
+            err "wrapper name \`${1}' is invalid"
+            ;;
+    esac
+}
+
+# -------------------------------------------------------------------------
+
+# warn message
+#
+# Shows a warning message.
+#
+warn() {
+    echo "${Prog_Name}: ${*}" 1>&2
+}
+
+# -------------------------------------------------------------------------
+
+# main
+#
+# Main program code.  Does argument parsing and executes the required
+# action.
+#
+main() {
+    args=$(getopt p:sw ${*})
+    [ ${?} -eq 0 ] || usage
+    set -- ${args}
+    what=package
+    while [ ${#} -gt 0 ]; do
+        case ${1} in
+            -p)
+                Prefix=$2; shift
+                Conf_Dir=@CONFDIR@${Prefix}
+                Db_Dir=@DBDIR@${Prefix}
+                ;;
+            -s)
+                Verbose=no
+                ;;
+            -w)
+                what=wrapper
+                ;;
+            --)
+                shift; break
+                ;;
+        esac
+        shift
+    done
+
+    if [ ${#} -eq 0 ]; then
+        usage
+    fi
+
+    action=${1}; shift
+    case ${action} in
+        auto|list|manual|rebuild|register|status|unregister)
+            action_${action}_${what} "${@}"
+            ;;
+        *)
+            err "unknown action \`${action}'"
+            ;;
+    esac
+
+    return 0
+}
+
+main "${@}"
+
+# vim: syntax=sh:expandtab:shiftwidth=4:softtabstop=4
diff --git a/pkgtools/pkg_alternatives/files/wrapper.man b/pkgtools/pkg_alternatives/files/wrapper.man
new file mode 100644
index 00000000000..9f5248b06e4
--- /dev/null
+++ b/pkgtools/pkg_alternatives/files/wrapper.man
@@ -0,0 +1,70 @@
+.\" $NetBSD: wrapper.man,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+.\"
+.\" pkg_alternatives - Generic wrappers for programs with similar interfaces
+.\" Copyright (c) 2005 Julio M. Merino Vidal <jmmv@NetBSD.org>
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Neither the name of The NetBSD Foundation nor the names of its
+.\"    contributors may be used to endorse or promote products derived
+.\"    from this software without specific prior written permission.
+.\" 3. Neither the name of author nor the names of its contributors may
+.\"    be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd January 25, 2005
+.Dt __TITLE__ __SECTION__
+.Os
+.Sh NAME
+.Nm __WRAPPER__
+.Nd generic wrapper created by the alternatives system
+.Sh SYNOPSIS
+.Nm
+.Op arguments
+.Sh DESCRIPTION
+.Nm
+is a generic wrapper created by the
+.Xr pkg_alternatives 1
+utility.
+Its purpose is to execute a program that provides a similar interface
+to the one expected by the more common name
+.Nm .
+.Pp
+The program to be really run is determined from a list of alternatives.
+You can check which one will be executed, as well as all available
+candidates, by issuing:
+.Bd -literal -offset indent
+$ pkg_alternatives -w status __WRAPPERBASE__
+.Ed
+.Pp
+Once you know which alternative is the chosen one, look at its manual page
+for more information.
+.Sh FILES
+.Bl -tag -width XXXX
+.It ~/.pkg_alternatives__PREFIX__/__WRAPPERBASE__
+User-specific list of candidates.
+.It __CONF_FILE__
+System-wide list of candidates, automatically configured by installed
+packages.
+.It __DB_FILE__
+System-wide list of candidates, manually configured by the administrator.
+.El
+.Sh SEE ALSO
+.Xr pkg_alternatives 1
+.Sh AUTHORS
+.An Julio M. Merino Vidal Aq jmmv@NetBSD.org
diff --git a/pkgtools/pkg_alternatives/files/wrapper.sh b/pkgtools/pkg_alternatives/files/wrapper.sh
new file mode 100644
index 00000000000..e4a757a2801
--- /dev/null
+++ b/pkgtools/pkg_alternatives/files/wrapper.sh
@@ -0,0 +1,64 @@
+#!__SH__
+#
+# $NetBSD: wrapper.sh,v 1.1.1.1 2005/01/25 13:00:46 jmmv Exp $
+#
+# pkg_alternatives - Generic wrappers for programs with similar interfaces
+# Copyright (c) 2005 Julio M. Merino Vidal <jmmv@NetBSD.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name of author nor the names of its contributors may
+#    be used to endorse or promote products derived from this software
+#    without alternative prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+wrapper="__WRAPPER__"
+progname="${wrapper##*/} (wrapper)"
+
+if [ ! -f __DB_FILE__ ]; then
+    echo "${progname}: cannot open __DB_FILE__" 1>&2
+    exit 1
+fi
+
+if [ $(id -un) = __ROOT_USER__ ]; then
+    userfile=
+else
+    userfile=~/.pkg_alternatives/${wrapper}
+fi
+alternatives=$(cat ${userfile} __CONF_FILE__ __DB_FILE__ 2>/dev/null | \
+               grep -v "^#" | tr ' ' '¬')
+
+found=
+for a in ${alternatives}; do
+    prog=$(echo ${a} | cut -d '¬' -f 1)
+    if [ -x ${prog} ]; then
+        found=$(echo ${a} | tr '¬' ' ')
+	break
+    fi
+done
+
+if [ -z "${found}" ]; then
+    echo "${progname}: no alternatives found" 1>&2
+    exit 1
+fi
+
+exec ${found} "${@}"