[Pm-utils] [PATCH 1/7] Simplify hook implementation.

[Victor Lowther]

	modified:   pm/HOWTO.hooks
	modified:   pm/functions.in
	modified:   pm/sleep.d/Makefile.am
	deleted:    pm/sleep.d/zzz

* Merge the functionality of find_hooks and run_hooks.  This results in
a new run_hooks function which is much simpler than the old one and is
much more resistant to breaking due to odd filenames.
* Actually implements the functionality mentioned in README where you
can create a nonexecutable file in /etc/pm/(sleep|power).d that will
prevent the copy in /usr/lib/pm-utils/(sleep|power).d from running.
* Undoes the "nonzero exit code means do not run on resume" and
auto-reverse pseudofeatures I added in the POSIX series. If anyone likes
them, they can be added back at the cost of either passing a function to
run_hooks or maintaining a global variable.
* Merges the functionality that was in zzz back into pm_main. Although
zzz was a slightly funny name, upon further reflection it was a bad idea
and makes it harder to implement some partitioning of functionality that
will be needed if/when the hooks are split into their own project.
* Updates the documentation to reflect these changes.
---
 pm/HOWTO.hooks         |   16 +----------
 pm/functions.in        |   65 +++++++++++++++++++++--------------------------
 pm/sleep.d/Makefile.am |    3 +-
 pm/sleep.d/zzz         |   10 -------
 4 files changed, 32 insertions(+), 62 deletions(-)

diff --git a/pm/HOWTO.hooks b/pm/HOWTO.hooks
index 482af72..43fe40d 100644
--- a/pm/HOWTO.hooks
+++ b/pm/HOWTO.hooks
@@ -26,20 +26,8 @@ All hooks are run in lexical sort order according to the C locale.
 SLEEP.D SPECIFIC NOTES
 
 For any given sleep/wakeup cycle, the hooks in sleep.d are run twice:
-Once in C lexical sort order before the system goes to sleep, and
-Once in reverse C lexical sort order when the system wakes up.
-
-If a hook does not need to be run when waking up, it SHOULD return a non-zero
-exit code -- this will signal the hook-running infrastructure to skip that
-hook when waking up.
-
-Similarly, if your hook only needs to run on system with certain specific
-configurations (such as the (0|9)5led hooks, which are IBM specific),
-or relies on certain specific commands that are not guaranteed to be present
-(such as the 10NetworkManager hook, which relies on D-Bus and Network Manager
-both being present), you SHOULD test for those conditions first and you SHOULD
-return a non-zero exit code if your hook is not applicable to the system it 
-is running on.
+* Once in C lexical sort order before the system goes to sleep, and
+* Once in reverse C lexical sort order when the system wakes up.
 
 CONVENIENCE FUNCTIONS
 
diff --git a/pm/functions.in b/pm/functions.in
index a9f0c1b..996c8dd 100644
--- a/pm/functions.in
+++ b/pm/functions.in
@@ -104,49 +104,38 @@ command_exists()
 	return $?
 }
 
-find_hooks() {
+run_hooks() {
 	# $1 = type of hook to find.  
+	# $2 = paramaters to pass to hooks.
+	# $3 = if present and equal to "reverse", run hooks backwards.
 	# Currently only power and sleep are meaningful.
 	local syshooks="${PM_UTILS_ETCDIR}/$1.d"
 	local phooks="${PM_UTILS_LIBDIR}/$1.d"
+	local sort="sort"
 	local base
-
-	for base in $(for f in $syshooks/*[!~] $phooks/*[!~];
-		do [ -f "$f" ] && echo ${f##*/} ; done | sort | uniq) ;
+	local hook
+	local oifs="${IFS}"
+	# the next two lines are not a typo or a formatting error!
+	local nifs="
+"
+	IFS="${nifs}" # tolerate spaces in filenames.
+	[ "$3" = "reverse" ] && sort="sort -r"
+	for base in $(IFS="${oifs}"; for f in $syshooks/*[!~] $phooks/*[!~];
+		do [ -f "$f" ] && echo ${f##*/} ; done | ${sort} | uniq) ;
 	do
-		if [ -x "$syshooks/$base" ]; then
-			echo $syshooks/$base
-		elif [ -x "$phooks/$base" ]; then
-			echo $phooks/$base
+		if [ -f "$syshooks/$base" ]; then
+			hook="$syshooks/$base"
+		elif [ -f "$phooks/$base" ]; then
+			hook="$phooks/$base"
 		fi
+		[ -x "${hook}" ] && {
+			IFS="${oifs}"
+			echo "$(date): running ${hook} $2"
+			"${hook}" $2
+			IFS="${nifs}"
+		}
 	done
-}
-
-run_hooks() {
-	# $1 = hooks to run
-	# $2 = parameters to pass to hooks
-	# $3 = if $3 = "reverse", then also run the hooks that ran sucessfully
-	#      backwards with parameters in $4
-        # $4 = parameters to pass to scripts when running backwards	
-	echo "$(date): running $1 hooks."
-	local hooks="$1"
-	local params="$2"
-	shift; shift
-	local revhooks
-	local file
-	for file in $(find_hooks "${hooks}"); do
-		echo "===== $(date): running hook: $file $params ====="
-		"$file" $params && revhooks="${file}${revhooks:+" ${revhooks}"}"
-	done
-	echo "$(date): done running $hooks:$params hooks."
-	if [ "x$1" = "xreverse" ]; then
-		echo "$(date): running $hooks hooks backwards."
-		for file in $revhooks; do
-			echo "===== $(date): running hook :$file $2 ====="
-			"${file}" $2
-		done
-		echo "$(date): done running $hooks:$2 backwards"
-	fi
+	IFS="${oifs}"
 }
 
 get_power_status()
@@ -200,7 +189,11 @@ pm_main()
 
 	rm -f "$INHIBIT"
 
-	run_hooks sleep "$1" reverse "$2"
+	run_hooks sleep "$1" 
+	command_exists "do_$1" && [ ! -e "${INHIBIT}" ] && { \
+		sync; "do_$1"
+	}
+	run_hooks sleep "$2" reverse
 
 	return 0
 }
diff --git a/pm/sleep.d/Makefile.am b/pm/sleep.d/Makefile.am
index 5092a42..256ee0b 100644
--- a/pm/sleep.d/Makefile.am
+++ b/pm/sleep.d/Makefile.am
@@ -13,8 +13,7 @@ sleep_SCRIPTS =			\
 	90clock			\
 	94cpufreq		\
 	95led			\
-	99video			\
-	zzz
+	99video
 
 EXTRA_DIST=$(sleep_SCRIPTS)
 
diff --git a/pm/sleep.d/zzz b/pm/sleep.d/zzz
deleted file mode 100755
index 202e3a0..0000000
--- a/pm/sleep.d/zzz
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/sh
-. "${PM_FUNCTIONS}"
-[ -e "${INHIBIT}" ] && return 1
-sync;sync;sync;
-case $1 in
-	suspend|hibernate|suspend_hybrid) "do_$1" ;;
-	resume|thaw) exit 0 ;;
-	*) exit 1 ;;
-esac
-exit $?
-- 
1.5.3.8