scripts: b/job parallel improvements — streaming results, input/output headers, -failfast

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/b/job

@@ -14,6 +14,7 @@
 #   -parallel  run the same prompt N times in parallel (default: 1)
 #   -keep      do not remove job(s) after printing result
 #   -bg        submit job and exit immediately; prints session id(s); implies -keep
+#   -failfast  on first failure, cancel remaining running jobs and exit
 
 set -euo pipefail
 
@@ -38,12 +39,13 @@ Flags:
   -parallel N       run the same prompt N times in parallel (default: 1)
   -keep             do not remove job(s) after printing result
   -bg               submit and exit immediately; prints job id(s); implies -keep
+  -failfast         on first failure, cancel remaining running jobs and exit
   -help             show this help
 EOF
     exit 0
 }
 
-name=; cwd=; agent=; backend=; model=; output=; parallel=1; keep=0; bg=0
+name=; cwd=; agent=; backend=; model=; output=; parallel=1; keep=0; bg=0; failfast=0
 
 while [ $# -gt 0 ]; do
     case $1 in
@@ -56,6 +58,7 @@ while [ $# -gt 0 ]; do
         -parallel)  parallel=$2; shift ;;
         -keep)      keep=1 ;;
         -bg)        bg=1; keep=1 ;;
+        -failfast)  failfast=1 ;;
         -help)      usage ;;
         --)         shift; break ;;
         -*) die "unknown flag: $1" ;;
@@ -99,9 +102,53 @@ if [ "$bg" -eq 1 ]; then
 fi
 
 rc=0
-for i in $(seq 0 $((parallel - 1))); do
+
+if [ "$parallel" -gt 1 ]; then
+    abort=$(mktemp)
+    trap 'rm -f "$abort"' EXIT
+    pids=()
+    for i in $(seq 0 $((parallel - 1))); do
         id="${name}-${i}"
         B="$MOUNT/b/$id"
+        (
+            while true; do
+                [ -s "$abort" ] && exit 1
+                status=$(tr -d '[:space:]' < "$B/status" 2>/dev/null) || { sleep 0.05; continue; }
+                case "$status" in
+                    done*)   break ;;
+                    failed*) printf 'subagent %s failed: %s\n' "$id" "$status" >&2
+                             if [ "$failfast" -eq 1 ]; then
+                                 echo 1 > "$abort"
+                                 for j in $(seq 0 $((parallel - 1))); do
+                                     jid="${name}-${j}"
+                                     [ "$jid" != "$id" ] && rm -r "$MOUNT/b/$jid" 2>/dev/null || true
+                                 done
+                             fi
+                             [ "$keep" -eq 0 ] && rm -r "$B" 2>/dev/null || true
+                             exit 1 ;;
+                    *)       sleep 0.05 ;;
+                esac
+            done
+            if [ -s "$abort" ]; then
+                [ "$keep" -eq 0 ] && rm -r "$B" 2>/dev/null || true
+                exit 1
+            fi
+            if [ -n "$output" ]; then
+                printf '{"session":"%s","result":%s}\n' "$id" \
+                    "$(cat "$B/result" 2>/dev/null | jq -Rs .)"
+            else
+                printf '=== %s ===\nInput: "%s"\nOutput: ' "$id" "$prompt"
+                cat "$B/result" 2>/dev/null
+                printf '\n'
+            fi
+            [ "$keep" -eq 0 ] && rm -r "$B" 2>/dev/null || true
+        ) &
+        pids+=($!)
+    done
+    for pid in "${pids[@]}"; do wait "$pid" || rc=1; done
+else
+    id="${name}-0"
+    B="$MOUNT/b/$id"
 
     while true; do
         status=$(tr -d '[:space:]' < "$B/status" 2>/dev/null) || { sleep 0.05; continue; }
@@ -116,12 +163,11 @@ for i in $(seq 0 $((parallel - 1))); do
         printf '{"session":"%s","result":%s}\n' "$id" \
             "$(cat "$B/result" 2>/dev/null | jq -Rs .)"
     else
-        [ "$parallel" -gt 1 ] && printf '=== %s ===\n' "$id"
         cat "$B/result" 2>/dev/null
         printf '\n'
     fi
 
     [ "$keep" -eq 0 ] && rm -r "$B" 2>/dev/null || true
-done
+fi
 
 exit $rc