[PATCH] paccache: add --age-atime and --age-mtime options

[wisp3rwind]

---
 I would feel a lot more confident about using the paccache systemd
 service if it kept packages based on age instead of just the few most
 recent.

 This patch adds the functionality to skip candidates that are not older
 (in terms of atime or mtime) than some specified age. It seems to work,
 but I'm not exactly a bash expert, so please review with care. I'd
 appreciate if this could be merged!

 doc/paccache.8.txt |  5 ++++
 src/paccache.sh.in | 58 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/doc/paccache.8.txt b/doc/paccache.8.txt
index db81283..c9e3807 100644
--- a/doc/paccache.8.txt
+++ b/doc/paccache.8.txt
@@ -38,6 +38,11 @@ Options
 	Scan for packages for a specific architecture. Default is to scan for
 	all architectures.
 
+*\--age-atime <age>*::
+*\--age-mtime <age>*::
+	Only consider packages for removal with atime respectively mtime older than
+	specified. The age can be given as '10d', '1m', '1y', '1y1m' etc.
+
 *-c, \--cachedir <dir>*::
 	Specify a different cache directory. This option can be used more than once.
 	Default is to use the cache directory configured in 'pacman.conf'.
diff --git a/src/paccache.sh.in b/src/paccache.sh.in
index 012ba9f..8ee5792 100644
--- a/src/paccache.sh.in
+++ b/src/paccache.sh.in
@@ -27,6 +27,7 @@ declare -r myver='@PACKAGE_VERSION@'
 
 declare -a cachedirs=() candidates=() cmdopts=() whitelist=() blacklist=()
 declare -i delete=0 dryrun=0 filecount=0 move=0 needsroot=0 totalsaved=0 verbose=0
+declare -i age_atime=0 age_mtime=0
 declare    delim=$'\n' keep=3 movedir= scanarch=
 
 QUIET=0
@@ -40,6 +41,29 @@ die() {
 	exit 1
 }
 
+# Parses the age --age-atime and --age-mtime arguments
+parse_age() {
+	declare -i age=0
+	if [[ $2 =~ ^[[:space:]]*([0-9]+[dmy][[:space:]]*)+$ ]]; then
+		# Add spaces to facilitate splitting
+		temp=${2//d/d }
+		temp=${temp//m/m }
+		temp=${temp//y/y }
+		read -a temp <<< "${temp[*]}"
+		for a in ${temp[@]}; do
+			num=${a:0: -1}
+			case ${a: -1} in
+				d) age=$(( age + num )) ;;
+				m) age=$(( age + num * 30 )) ;;
+				y) age=$(( age + num * 365 )) ;;
+			esac
+		done
+	else
+		die "argument '%s' to option '%s' must be of the form '([0-9]+[dmy])+'" "$2" "$1"
+	fi
+	echo $(( age * 24 * 60 * 60 ))
+}
+
 # reads a list of files on stdin and prints out deletion candidates
 pkgfilter() {
 	# there's whitelist and blacklist parameters passed to this
@@ -174,6 +198,10 @@ Usage: ${myname} <operation> [options] [targets...]
     -r, --remove          remove candidate packages.
 
   Options:
+    --age-atime <age>
+    --age-mtime <age>     keep packages with an atime/mtime that is not at least
+                          <age> ago, where <age> is given as '10d', '1m', '1y',
+                          '1y1m' etc.
     -a, --arch <arch>     scan for "arch" (default: all architectures).
     -c, --cachedir <dir>  scan "dir" for packages. can be used more than once.
                           (default: read from @sysconfdir@/pacman.conf).
@@ -200,7 +228,8 @@ version() {
 
 OPT_SHORT=':a:c:dfhi:k:m:qrsuVvz'
 OPT_LONG=('arch:' 'cachedir:' 'dryrun' 'force' 'help' 'ignore:' 'keep:' 'move'
-          'nocolor' 'quiet' 'remove' 'uninstalled' 'version' 'verbose' 'null')
+          'nocolor' 'quiet' 'remove' 'uninstalled' 'version' 'verbose' 'null'
+          'age-atime:' 'age-mtime:')
 
 if ! parseopts "$OPT_SHORT" "${OPT_LONG[@]}" -- "$@"; then
 	exit 1
@@ -210,6 +239,18 @@ unset OPT_SHORT OPT_LONG OPTRET
 
 while :; do
 	case $1 in
+		--age-atime)
+			age_atime=$(parse_age "$1" "$2")
+			if (( $? )); then
+			  exit 1
+			fi
+			shift ;;
+		--age-mtime)
+			age_mtime=$(parse_age "$1" "$2")
+			if (( $? )); then
+			  exit 1
+			fi
+			shift ;;
 		-a|--arch)
 			scanarch=$2
 			shift ;;
@@ -319,6 +360,21 @@ for cachedir in "${cachedirs[@]}"; do
 	popd &>/dev/null
 done
 
+# remove any candidates that are not old enough yet
+if (( $age_atime || $age_mtime )); then
+  currtime=$(date +%s)
+  for cand in "${candidates[@]}"; do
+    IFS=';' read -d '' -a temp <<< $(stat --format '%X;%Y' "$cand")
+    if (( ( $(( $currtime - ${temp[0]} )) > $age_atime ) && \
+          ( $(( $currtime - ${temp[1]} )) > $age_mtime ) \
+	  )); then
+      candtemp+=("$cand")
+    fi
+  done
+  candidates=("${candtemp[@]}")
+  unset candtemp
+fi
+
 if (( ! ${#candidates[*]} )); then
 	msg 'no candidate packages found for pruning'
 	exit 0
-- 
2.19.0