qcd: Allow database file to be symlinked

The `sed -i` calls in the "change" and "remove" commands will overwrite
a symlinked database file with a real file, destroying the symlink.

To prevent this and allow the database file to be symlinked (to, say,
allow it to be tracked in a dotfiles repo), use a redirection technique
as described here:
https://www.cyberciti.biz/faq/howto-prevent-sed-i-from-destroying-symlinks-on-linux-unix/

Using this alternate method, we preserve symlinks, and even create a
backup file as before.

1 files changed, 7 insertions, 2 deletions

diff --git a/qcd b/qcd
index 091ba1a..8453b58 100755
--- a/qcd
+++ b/qcd
@@ -59,8 +59,12 @@ function __qcd_change_shortcut () {
 	if __qcd_shortcut_exists $shortcut; then
 		path=$(__qcd_absolute_path "$path")
 
+		cp $QCD_DATABASE_FILE "${QCD_DATABASE_FILE}.bak"
+
 		# The `//\//\/` escapes slashes in the path so that `sed` doesn't complain
-		sed -i.bak -E "s/^${shortcut}	.+$/${shortcut}	${path//\//\\/}/" $QCD_DATABASE_FILE
+		sed -E "s/^${shortcut}	.+$/${shortcut}	${path//\//\\/}/" \
+			< "${QCD_DATABASE_FILE}.bak" \
+			> $QCD_DATABASE_FILE
 	fi
 }
 
@@ -68,7 +72,8 @@ function __qcd_remove_shortcut () {
 	local shortcut=$1
 
 	if __qcd_shortcut_exists $shortcut; then
-		sed -i.bak -E "/^${shortcut}	.+/d" $QCD_DATABASE_FILE
+		cp $QCD_DATABASE_FILE "${QCD_DATABASE_FILE}.bak"
+		sed -E "/^${shortcut}	.+/d" < "${QCD_DATABASE_FILE}.bak" > $QCD_DATABASE_FILE
 	fi
 }