[PATCH v3 1/2] kdumpctl: follow symlink when checking for modified files

[Kairui Song]

Previously only the symlink's timestamp is used for checking if file are
modified, this will not trigger a rebuild if the symlink target it
modified.

So check both symlink timestamp and symlink target timestamp, rebuild
the initramfs on both symlink changed and target changed.

Also give a proper error message if the file doesn't exist.

Signed-off-by: Kairui Song <kasong(a)redhat.com&gt;
---
 kdumpctl | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/kdumpctl b/kdumpctl
index 75eebac..739f162 100755
--- a/kdumpctl
+++ b/kdumpctl
@@ -338,11 +338,23 @@ check_files_modified()
 	[ $? -ne 0 ] && return 2
 
 	for file in $files; do
-		time_stamp=`stat -c "%Y" $file`
-		if [ "$time_stamp" -gt "$image_time" ]; then
-			modified_files="$modified_files $file"
+		if [ -e "$file" ]; then
+			time_stamp=`stat -c "%Y" $file`
+			if [ "$time_stamp" -gt "$image_time" ]; then
+				modified_files="$modified_files $file"
+			fi
+			if [ -L "$file" ]; then
+				file=$(readlink -m $file)
+				time_stamp=`stat -c "%Y" $file`
+				if [ "$time_stamp" -gt "$image_time" ]; then
+					modified_files="$modified_files $file"
+				fi
+			fi
+		else
+			echo "$file doesn't exist"
 		fi
 	done
+
 	if [ -n "$modified_files" ]; then
 		echo "Detected change(s) in the following file(s):"
 		echo -n "  "; echo "$modified_files" | sed 's/\s/\n  /g'
-- 
2.20.1