1 files changed, 151 insertions, 0 deletions
diff --git a/common-functions b/common-functions
new file mode 100644
index 0000000..58536cf
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+++ b/common-functions
@@ -0,0 +1,151 @@
+#!/bin/sh
+
+# Comments on coding style:
+#  * shift mandatory function arguments: Provokes error if missing
+#  * quote variables: We want to support oddities like spaces in paths
+
+function preserveolderfile() {
+	## DESC: Preserve copy of file, unless one exists already
+	# File to tweak
+	file="$1"; shift
+	# Extension used for new backup
+	newext="$1"
+	# Space-delimited list of possible extensions, default last
+	extensions="orig old"
+	for ext in $extensions; do
+		backupfile="$file.$ext"
+		[ "$ext" = "$newext" ] && newext_valid="yes"
+		if [ -f "$backupfile" ]; then
+			[ -n "$DEBUG" ] && echo "DEBUG: Backup file \"$backupfile\" not found - continuing." >&2
+			continue
+		elif [ -e "$backupfile" ]; then
+			echo "ERROR: Backup file \"$backupfile\" is not a regular file." >&2
+			return 1
+		else
+			[ -n "$DEBUG" ] && echo "DEBUG: Backup file \"$backupfile\" found - exit silently." >&2
+			return 0
+		fi
+	done
+	if [ -n "$newext" ];then
+		if [ "$newext_valid" = "yes" ]; then
+			backupfile="$file.$newext"
+		else
+			echo "WARNING: Backup extension \"$newext\" is invalid - using default instead" >&2
+		fi
+	fi
+	if [ -f "$file" ]; then
+		cp -p "file" "$backupfile"
+	elif [ -e "$file" ]; then
+		echo "ERROR: Backup of file \"$file\" failed - not a regular file." >&2
+		return 1
+	else
+		touch "$backupfile"
+	fi
+	return 0
+}
+
+function enableoraddlines() {
+	## DESC: Add lines to file, or replace if similar exist already
+	# File to tweak
+	file="$1"; shift
+	# Word number in line to search for and replace if found
+	# FIXME: This is broken - wordno unconditionally becomes firstword later on
+	wordno="$1"; shift
+	[ -e "$file" ] || touch "$file"
+	for line; do
+		[ -z "$line" ] && continue
+		firstword=$(echo "$line" | awk "{print \$$wordno}")
+		# FIXME: Why doesn't it work to print ARGVOUT in END block?
+		linemissing=$(perl -i -pe "END { print \"$line\\n\" unless \$seen } s¡^[#;\s]*($firstword)\s.*¡$line\\n¡ and \$seen++" "$file")
+#"This stray quote is only to please buggy mc (cooledit) code hiliting
+		[ -n "$linemissing" ] && echo $linemissing >> "$file"
+	done
+	# FIXME: Figure out what exits non-zero above
+	return 0
+}
+
+function preserveandaddlines() {
+	## DESC: Backup older file and add lines to it
+	# File to tweak
+	file="$1"; shift
+	# Extension of backup file
+	ext="$1"; shift
+	# Word number in line to search for and replace if found
+	# FIXME: This is broken - wordno unconditionally becomes firstword later on
+	wordno="$1"; shift
+	preserveolderfile "$file" "$ext"
+#	enableoraddlines "$file" "$wordno" $@
+	# FIXME: Somehow avoid expansion, to avoid having to duplicate the whole enableoraddlines()
+	[ -e "$file" ] || touch "$file"
+	for line; do
+		[ -z "$line" ] && continue
+		firstword=$(echo "$line" | awk "{print \$$wordno}")
+		# FIXME: Why doesn't it work to print ARGVOUT in END block?
+		linemissing=$(perl -i -pe "END { print \"$line\\n\" unless \$seen } s¡^[#;\s]*($firstword)\s.*¡$line\\n¡ and \$seen++" "$file")
+#"This stray quote is only to please buggy mc (cooledit) code hiliting
+		[ -n "$linemissing" ] && echo $linemissing >> "$file"
+	done
+	# FIXME: Figure out what exits non-zero above
+	return 0
+}
+
+function preserveandhashdisablelines() {
+	## DESC: Backup older file and disable lines in it
+	# File to tweak
+	file="$1"; shift
+	# Extension of backup file
+	ext="$1"; shift
+	# Word number in line to search for and replace if found
+	# FIXME: This is broken - wordno unconditionally becomes firstword later on
+	wordno="$1"; shift
+	preserveolderfile "$file" "$ext"
+#	disablelines "$file" "$wordno" "#" $@
+	# FIXME: Somehow avoid expansion, to make possibe a separate disablelines()
+	[ -e "$file" ] || touch "$file"
+	for line; do
+		[ -z "$line" ] && continue
+		firstword=$(echo "$line" | awk "{print \$$wordno}")
+		# FIXME: Why doesn't it work to print ARGVOUT in END block?
+		linemissing=$(perl -i -pe "END { print \"$line\\n\" unless \$seen } s¡^(\s*$firstword)\s.*¡#$line\\n¡ and \$seen++" "$file")
+#"This stray quote is only to please buggy mc (cooledit) code hiliting
+		[ -n "$linemissing" ] && echo >2 "Line \"$linemissing\" not found to disable in $file"
+	done
+	# FIXME: Figure out what exits non-zero above
+	return 0
+}
+
+function perlrelines() {
+	## DESC: Apply perl regex to lines of a single file
+	# File to tweak
+	file=$1; shift
+	backupfile="`savebackupfile "$file"`"
+	for regexp; do
+		perl -pi -e "$regexp" "$file"
+	done
+	cleanbackupfile "$file" "$backupfile"
+
+	# FIXME: Figure out what exits non-zero above
+	return 0
+}
+
+function mkgrubdevmap() {
+	## DESC: Spit out GRUB config used for /boot/grub/devices.map
+	device="$1"; shift
+	cat <<EOF
+(fd0) /dev/fd0
+(hd0) $device
+EOF
+}
+
+function addaddons() {
+	context="$1"; shift
+	addon_context="$1"; shift
+	for addon in $@; do
+		context_here="$(eval echo \$\{${addon_context}_$addon\})"
+		if [ -n "$context_here" ]; then
+			eval ${context}=\"\$${context} \$context_here\"
+		else
+			echo "Warning: Variable \"${addon_context}_${addon}\" empty or undefined!"
+		fi
+done
+}