You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

277 lines
7.4 KiB

#!/usr/bin/env nix-shell
#! nix-shell -i bash -p coreutils gnugrep gnused
################################################################################
# nix-diff.sh #
################################################################################
# This script "diffs" Nix profile generations. #
# #
# Example: #
################################################################################
# > nix-diff.sh 90 92 #
# + gnumake-4.2.1 #
# + gnumake-4.2.1-doc #
# - htmldoc-1.8.29 #
################################################################################
# The example shows that as of generation 92 and since generation 90, #
# gnumake-4.2.1 and gnumake-4.2.1-doc have been installed, while #
# htmldoc-1.8.29 has been removed. #
# #
# The example above shows the default, minimal output mode of this script. #
# For more features, run `nix-diff.sh -h` for usage instructions. #
################################################################################
usage() {
cat <<EOF
usage: nix-diff.sh [-h | [-p profile | -s] [-q] [-l] [range]]
-h: print this message before exiting
-q: list the derivations installed in the parent generation
-l: diff every available intermediate generation between parent and
child
-p profile: specify the Nix profile to use
* defaults to ~/.nix-profile
-s: use the system profile
* equivalent to: -p /nix/var/nix/profiles/system
profile: * should be something like /nix/var/nix/profiles/default, not a
generation link like /nix/var/nix/profiles/default-2-link
range: the range of generations to diff
* the following patterns are allowed, where A, B, and N are positive
integers, and G is the currently active generation:
A..B => diffs from generation A to generation B
~N => diffs from the Nth newest generation (older than G) to G
A => diffs from generation A to G
* defaults to ~1
EOF
}
usage_tip() {
echo 'run `nix-diff.sh -h` for usage instructions' >&2
exit 1
}
while getopts :hqlp:s opt; do
case $opt in
h)
usage
exit
;;
q)
opt_query=1
;;
l)
opt_log=1
;;
p)
opt_profile=$OPTARG
;;
s)
opt_profile=/nix/var/nix/profiles/system
;;
\?)
echo "error: invalid option -$OPTARG" >&2
usage_tip
;;
esac
done
shift $((OPTIND-1))
if [ -n "$opt_profile" ]; then
if ! [ -L "$opt_profile" ]; then
echo "error: expecting \`$opt_profile\` to be a symbolic link" >&2
usage_tip
fi
else
opt_profile=$(readlink ~/.nix-profile)
if (( $? != 0 )); then
echo 'error: unable to dereference `~/.nix-profile`' >&2
echo 'specify the profile manually with the `-p` flag' >&2
usage_tip
fi
fi
list_gens() {
nix-env -p "$opt_profile" --list-generations \
| sed -r 's:^\s*::' \
| cut -d' ' -f1
}
current_gen() {
nix-env -p "$opt_profile" --list-generations \
| grep -E '\(current\)\s*$' \
| sed -r 's:^\s*::' \
| cut -d' ' -f1
}
neg_gen() {
local i=0 from=$1 n=$2 tmp
for gen in $(list_gens | sort -rn); do
if ((gen < from)); then
tmp=$gen
((i++))
((i == n)) && break
fi
done
if ((i < n)); then
echo -n "error: there aren't $n generation(s) older than" >&2
echo " generation $from" >&2
return 1
fi
echo $tmp
}
match() {
argv=("$@")
for i in $(seq $(($#-1))); do
if grep -E "^${argv[$i]}\$" <(echo "$1") >/dev/null; then
echo $i
return
fi
done
echo 0
}
case $(match "$1" '' '[0-9]+' '[0-9]+\.\.[0-9]+' '~[0-9]+') in
1)
diffTo=$(current_gen)
diffFrom=$(neg_gen $diffTo 1)
(($? == 1)) && usage_tip
;;
2)
diffFrom=$1
diffTo=$(current_gen)
;;
3)
diffFrom=${1%%.*}
diffTo=${1##*.}
;;
4)
diffTo=$(current_gen)
diffFrom=$(neg_gen $diffTo ${1#*~})
(($? == 1)) && usage_tip
;;
0)
echo 'error: invalid invocation' >&2
usage_tip
;;
esac
dirA="${opt_profile}-${diffFrom}-link"
dirB="${opt_profile}-${diffTo}-link"
declare -a temp_files
temp_length() {
echo -n ${#temp_files[@]}
}
temp_make() {
temp_files[$(temp_length)]=$(mktemp)
}
temp_clean() {
rm -f ${temp_files[@]}
}
temp_name() {
echo -n "${temp_files[$(($(temp_length)-1))]}"
}
trap 'temp_clean' EXIT
temp_make
versA=$(temp_name)
refs=$(nix-store -q --references "$dirA")
(( $? != 0 )) && exit 1
echo "$refs" \
| grep -v env-manifest.nix \
| sort \
> "$versA"
print_tag() {
local gen=$1
nix-env -p "$opt_profile" --list-generations \
| grep -E "^\s*${gen}" \
| sed -r 's:^\s*::' \
| sed -r 's:\s*$::'
}
if [ -n "$opt_query" ]; then
print_tag $diffFrom
cat "$versA" \
| sed -r 's:^[^-]+-(.*)$: \1:'
print_line=1
fi
if [ -n "$opt_log" ]; then
gens=$(for gen in $(list_gens); do
((diffFrom < gen && gen < diffTo)) && echo $gen
done)
# Force the $diffTo generation to be included in this list, instead of using
# `gen <= diffTo` in the preceding loop, so we encounter an error upon the
# event of its nonexistence.
gens=$(echo "$gens"
echo $diffTo)
else
gens=$diffTo
fi
temp_make
add=$(temp_name)
temp_make
rem=$(temp_name)
temp_make
out=$(temp_name)
for gen in $gens; do
[ -n "$print_line" ] && echo
temp_make
versB=$(temp_name)
dirB="${opt_profile}-${gen}-link"
refs=$(nix-store -q --references "$dirB")
(( $? != 0 )) && exit 1
echo "$refs" \
| grep -v env-manifest.nix \
| sort \
> "$versB"
in=$(comm -3 -1 "$versA" "$versB")
sed -r 's:^[^-]*-(.*)$:\1+:' <(echo "$in") \
| sort -f \
> "$add"
un=$(comm -3 -2 "$versA" "$versB")
sed -r 's:^[^-]*-(.*)$:\1-:' <(echo "$un") \
| sort -f \
> "$rem"
cat "$rem" "$add" \
| sort -f \
| sed -r 's:(.*)-$:- \1:' \
| sed -r 's:(.*)\+$:\+ \1:' \
| grep -v '^$' \
> "$out"
if [ -n "$opt_query" -o -n "$opt_log" ]; then
lines=$(wc -l "$out" | cut -d' ' -f1)
tag=$(print_tag "$gen")
(( $? != 0 )) && exit 1
if [ $lines -eq 0 ]; then
echo "$tag (no change)"
else
echo "$tag"
fi
cat "$out" \
| sed 's:^: :'
print_line=1
else
echo "diffing from generation $diffFrom to $diffTo"
cat "$out"
fi
versA=$versB
done
exit 0