fix(cli): validate empty option values and improve --saving-file handling

Reject empty values for --encodefile, --saving-file, and --preset in
both the space-separated and equals forms (e.g. --preset= now exits
with a clear error instead of failing later with a confusing message
from the allowlist check).

Track whether --saving-file was set explicitly via SAVING_FILE_EXPLICIT.
Warn when --saving-file is used without --saving, but do not exit, to
allow the combination in aliases and wrapper scripts.

Change the savings log format from space-separated to TSV and write a
header line on first creation, making the file easier to parse both by
eye and programmatically.

1 files changed, 36 insertions, 1 deletions

diff --git a/transcode.sh b/transcode.sh
index a74b6c3..2866e97 100755
--- a/transcode.sh
+++ b/transcode.sh
@@ -122,6 +122,7 @@ ONLY_IF_SMALLER=0
 PRESET_NAME="default"
 SAVING=0
 SAVING_FILE="transcode_savings"
+SAVING_FILE_EXPLICIT=0
 declare -A SKIP_CODECS
 
 REMAINING_ARGS=()
@@ -439,10 +440,18 @@ while [[ $# -gt 0 ]]; do
       error "Missing value for $1"
       exit $EXIT_USAGE_ERROR
     }
+    [[ -n "$2" ]] || {
+      error "Value for $1 must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     ENCODE_FILE="$2"
     shift 2
     ;;
   --encodefile=*)
+    [[ -n "${1#*=}" ]] || {
+      error "Value for --encodefile must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     ENCODE_FILE="${1#*=}"
     shift
     ;;
@@ -471,11 +480,21 @@ while [[ $# -gt 0 ]]; do
       error "Missing value for $1"
       exit $EXIT_USAGE_ERROR
     }
+    [[ -n "$2" ]] || {
+      error "Value for $1 must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     SAVING_FILE="$2"
+    SAVING_FILE_EXPLICIT=1
     shift 2
     ;;
   --saving-file=*)
+    [[ -n "${1#*=}" ]] || {
+      error "Value for --saving-file must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     SAVING_FILE="${1#*=}"
+    SAVING_FILE_EXPLICIT=1
     shift
     ;;
   -S | --skip-codec)
@@ -499,10 +518,18 @@ while [[ $# -gt 0 ]]; do
       error "Missing value for $1"
       exit $EXIT_USAGE_ERROR
     }
+    [[ -n "$2" ]] || {
+      error "Value for $1 must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     PRESET_NAME="$2"
     shift 2
     ;;
   --preset=*)
+    [[ -n "${1#*=}" ]] || {
+      error "Value for --preset must not be empty"
+      exit $EXIT_USAGE_ERROR
+    }
     PRESET_NAME="${1#*=}"
     shift
     ;;
@@ -543,6 +570,10 @@ if [[ $SAVING -eq 1 ]]; then
   }
 fi
 
+if [[ $SAVING_FILE_EXPLICIT -eq 1 && $SAVING -eq 0 ]]; then
+  error "--saving-file has no effect without --saving"
+fi
+
 if [[ ! "$NICE_VALUE" =~ ^-?[0-9]+$ ]] || ((NICE_VALUE < -20 || NICE_VALUE > 19)); then
   error "Invalid nice value (must be an integer between -20 and 19):" "$NICE_VALUE"
   exit $EXIT_USAGE_ERROR
@@ -724,7 +755,11 @@ encode_one() {
       else
         pct=0
       fi
-      printf "%s %s %s %s%%\n" "$filename" "$original_filesize" "$new_filesize" "$pct" >>"$SAVING_FILE"
+      # Write a header line if the savings file does not yet exist.
+      if [[ ! -f "$SAVING_FILE" ]]; then
+        printf "filename\toriginal_bytes\tnew_bytes\tsaved_pct\n" >"$SAVING_FILE"
+      fi
+      printf "%s\t%s\t%s\t%s%%\n" "$filename" "$original_filesize" "$new_filesize" "$pct" >>"$SAVING_FILE"
     fi
 
     mv -f -- "$tmp" "$file"