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Revision 1.1 - (hide annotations) (download)
Tue Oct 7 17:21:40 2003 UTC (10 years, 11 months ago) by liquidx
Branch: MAIN
initial commit, main user is python, but i except some more other packages
to follow

1 liquidx 1.1 # Copyright 1999-2003 Gentoo Technologies, Inc.
2     # Distributed under the terms of the GNU General Public License v2
3     # $Header: /home/cvsroot/gentoo-x86/eclass/rpm.eclass,v 1.8 2003/08/31 19:43:05 liquidx Exp $
4    
5     # Author : Alastair Tse <liquidx@gentoo.org> (03 Oct 2003)
6     # Short Desc: Creates symlink to the latest version of multiple slotted
7     # packages.
8     #
9     # Long Desc:
10     #
11     # When a package is SLOT'ed, very often we need to have a symlink to the
12     # latest version. However, depending on the order the user has merged them,
13     # more often than not, the symlink maybe clobbered by the older versions.
14     #
15     # This eclass provides a convenience function that needs to be given a
16     # list of alternatives (descending order of recent-ness) and the symlink.
17     # It will choose the latest version if can find installed and create
18     # the desired symlink.
19     #
20     # There are two ways to use this eclass. First is by declaring two variables
21     # $SOURCE and $ALTERNATIVES where $SOURCE is the symlink to be created and
22     # $ALTERNATIVES is a list of alternatives. Second way is the use the function
23     # alternatives_makesym() like the example below.
24     #
25     # Example:
26     #
27     # pkg_postinst() {
28     # alternatives_makesym "/usr/bin/python" "/usr/bin/python2.3" "/usr/bin/python2.2"
29     # }
30     #
31     # The above example will create a symlink at /usr/bin/python to either
32     # /usr/bin/python2.3 or /usr/bin/python2.2. It will choose python2.3 over
33     # python2.2 if both exist.
34     #
35     # Alternatively, you can use this function:
36     #
37     # pkg_postinst() {
38     # alternatives_auto_makesym "/usr/bin/python" "/usr/bin/python[0-9].[0-9]"
39     # }
40     #
41     # This will use bash pathname expansion to fill a list of alternatives it can
42     # link to. It is probably more robust against version upgrades. You should
43     # consider using this unless you are want to do something special.
44     #
45     ECLASS="alternatives"
46     INHERITED="$INHERITED $ECLASS"
47    
48     # automatic deduction based on a symlink and a regex mask
49     alternatives_auto_makesym() {
50     local SOURCE REGEX ALT
51     local unsorted
52     SOURCE=$1
53     REGEX=$2
54    
55     ALT="`ls -1 ${ROOT}${REGEX} | sort -r | xargs`"
56     if [ -n "${ALT}" ]; then
57     alternatives_makesym ${SOURCE} ${ALT}
58     else
59     eerror "regex ${REGEX} doesn't match any files."
60     fi
61     }
62    
63     alternatives_makesym() {
64     local ALTERNATIVES=""
65     local SOURCE=""
66    
67     # usage: alternatives_makesym <resulting symlink> [alternative targets..]
68     SOURCE=$1
69     shift
70     ALTERNATIVES=$@
71    
72     # step through given alternatives from first to last
73     # and if one exists, link it and finish.
74    
75     for alt in ${ALTERNATIVES}; do
76     if [ -f "${ROOT}${alt}" ]; then
77     if [ -L "${ROOT}${SOURCE}" ]; then
78     rm -f ${ROOT}${SOURCE}
79     fi
80     einfo "Linking ${alt} to ${SOURCE}"
81     ln -s ${alt} ${ROOT}${SOURCE}
82     break
83     fi
84     done
85    
86     # report any errors
87     if [ ! -L ${ROOT}${SOURCE} ]; then
88     ewarn "Unable to establish ${SOURCE} symlink"
89     elif [ ! -f "`readlink ${ROOT}${SOURCE}`" -a ! -f "${ROOT}`readlink ${ROOT}${SOURE}`" ]; then
90     ewarn "${SOURCE} is a dead symlink."
91     fi
92     }
93    
94     alternatives_pkg_postinst() {
95     if [ -n "${ALTERNATIVES}" -a -n "${SOURCE}" ]; then
96     alternatives_makesym ${SOURCE} ${ALTERNATIVES}
97     fi
98     }
99    
100     alternatives_pkg_postrm() {
101     if [ -n "${ALTERNATIVES}" -a -n "${SOURCE}" ]; then
102     alternatives_makesym ${SOURCE} ${ALTERNATIVES}
103     fi
104     }
105    
106     EXPORT_FUNCTIONS pkg_postinst pkg_postrm

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