Fix more warnings of shellcheck(1), use "[[ ... ]]" instead of "[ ... ]"

diff --git a/bin/backup-script b/bin/backup-script
index bfcc2543c1d0e5c2df8ae613a8315b13e48c0740..5c070261358369d1ef1f36652ea877878ac19023 100755 (executable)
--- a/bin/backup-script
+++ b/bin/backup-script
@@ -360,7 +360,7 @@ if [ -n "$pre_exec" ]; then
 fi
 
 for f in $sys; do
-       [ -r "$f" -a -f "$f" ] || continue
+       [[ -r "$f" && -f "$f" ]] || continue
 
        fname=$(basename "$f")
        case "$fname" in
@@ -399,13 +399,13 @@ for f in $sys; do
        source "$f"
 
        # Compatibility with backup-pull(1) script: Fix up configuration
-       [ "$system" = "$fname" -a -n "$host" ] \
+       [[ "$system" = "$fname" && -n "$host" ]] \
                && system="$host"
-       [ "$source_root" = "$default_source_root" -a -n "$source" ] \
+       [[ "$source_root" = "$default_source_root" && -n "$source" ]] \
                && source_root="$source"
-       [ -z "$job_pre_exec" -a -n "$pre_exec" ] \
+       [[ -z "$job_pre_exec" && -n "$pre_exec" ]] \
                && job_pre_exec="$pre_exec"
-       [ -z "$job_post_exec" -a -n "$post_exec" ] \
+       [[ -z "$job_post_exec" && -n "$post_exec" ]] \
                && job_post_exec="$post_exec"
 
        # Compatibility with backup-pull(1) script: Restore global values ...
@@ -413,7 +413,7 @@ for f in $sys; do
        post_exec="$post_exec_saved"
 
        # Validate configuration
-       if [ "$system" = "localhost" -o "$system" = "127.0.0.1" ]; then
+       if [[ "$system" = "localhost" || "$system" = "127.0.0.1" ]]; then
                # Local system
                local=1
                compress=0
@@ -455,7 +455,7 @@ for f in $sys; do
 
        sys_target="$target/$fname"
        sys_root="$sys_target"
-       if [ "$DRYRUN" -eq 0 -a ! -e "$sys_target" ]; then
+       if [[ "$DRYRUN" -eq 0 && ! -e "$sys_target" ]]; then
                if [ $generations -gt 0 ]; then
                        CreateSubvolume "$sys_target"
                else
@@ -467,7 +467,7 @@ for f in $sys; do
                fi
        fi
 
-       if [ "$local" -eq 0 -a "$ping" -ne 0 ]; then
+       if [[ "$local" -eq 0 && "$ping" -ne 0 ]]; then
                # Check if system is alive
                ping -c 1 "$system" >/dev/null 2>&1
                if [ $? -ne 0 ]; then
@@ -488,7 +488,7 @@ for f in $sys; do
 
                Initialize_Last_SysTarget_Snapshot "$sys_target" || continue
 
-               if [ -n "$last" -a ! -e "$last/.stamp" ]; then
+               if [[ -n "$last" && ! -e "$last/.stamp" ]]; then
                        # Old backup directory without "stamp file", continue
                        echo "Found incomplete snapshot in \"$last\", reusing and renaming it ..."
                        RenameSubvolume "$last" "$sys_target"
@@ -595,7 +595,7 @@ for f in $sys; do
        fi
 
        echo -n "End date: "; date
-       if [ $ret -eq 0 -o $ret -eq 24 ]; then
+       if [[ $ret -eq 0 || $ret -eq 24 ]]; then
                [ $ret -eq 24 ] && count_ok_vanished=$count_ok_vanished+1
 
                echo "System \"$system\" completed with status $ret, OK."
@@ -619,7 +619,7 @@ for f in $sys; do
                # Clean up old generations
                declare -i gen_count=$generations+2
                to_delete=$(ls -1t "$sys_root" 2>/dev/null | tail -n+$gen_count | sort)
-               if [ -n "$to_delete" -a $ok -eq 1 ]; then
+               if [[ -n "$to_delete" && $ok -eq 1 ]]; then
                        [ "$DRYRUN" -eq 0 ] \
                                && echo "Deleting old backup generations (keep $generations) ..." \
                                || echo " *** Trial run, not deleting old generations:"