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a904guy/killgrep

Created September 17, 2025 20:22
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  1. a904guy created this gist Sep 17, 2025.
    142 changes: 142 additions & 0 deletions killgrep
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,142 @@
    #!/usr/bin/env bash
    # killgrep: kill processes by regex match on the process name (/proc/<pid>/comm)
    # Default matching is case-insensitive.

    set -o pipefail

    usage() {
    cat <<EOF
    Usage: $(basename "$0") [-s SIGNAL] [-I] [-x] [-n] [-u USER] pattern
    pattern ERE applied to process name (comm), not full command line
    Options:
    -s SIGNAL Signal to send (default: TERM). Examples: HUP, INT, TERM, KILL, 9
    -I Case-sensitive match. By default matching is case-insensitive
    -x Exact match (treat pattern as a literal name)
    -n Dry run. Print matches without sending signals
    -u USER Only match processes owned by USER
    -h Show this help
    EOF
    }

    signal="TERM"
    insensitive=1 # default: case-insensitive
    exact=0
    dry_run=0
    user_filter=""

    while getopts "s:Ixnu:Ch" opt; do
    case "$opt" in
    s) signal="$OPTARG" ;;
    I) insensitive=0 ;; # force case-sensitive
    x) exact=1 ;;
    n) dry_run=1 ;;
    u) user_filter="$OPTARG" ;;
    C) insensitive=0 ;; # alias for -I
    h) usage; exit 0 ;;
    *) usage; exit 1 ;;
    esac
    done
    shift $((OPTIND - 1))

    if [ $# -lt 1 ]; then
    usage
    exit 1
    fi

    pattern="$1"

    if [ "$exact" -eq 1 ]; then
    # Escape regex meta for literal exact match on name
    pattern="$(printf '%s' "$pattern" | sed -E 's/[][(){}.^$|*+?\\]/\\&/g')"
    pattern="^${pattern}$"
    fi

    self_pid=$$
    parent_pid=$PPID

    declare -a kill_pids
    declare -A name_by_pid

    for d in /proc/[0-9]*; do
    pid="${d#/proc/}"

    # skip pid 1, self, and parent shell
    if [[ "$pid" -eq 1 || "$pid" -eq "$self_pid" || "$pid" -eq "$parent_pid" ]]; then
    continue
    fi

    # read process name
    if ! read -r comm < "$d/comm" 2>/dev/null; then
    continue
    fi

    # skip kernel-style bracketed threads
    [[ "$comm" == \[*\] ]] && continue

    # user filter if requested
    if [[ -n "$user_filter" ]]; then
    proc_user="$(stat -c %U "$d" 2>/dev/null || echo "")"
    [[ -z "$proc_user" || "$proc_user" != "$user_filter" ]] && continue
    fi

    # match against process name only
    if [ "$insensitive" -eq 1 ]; then
    if printf '%s\n' "$comm" | grep -Eqi -- "$pattern"; then
    kill_pids+=("$pid")
    name_by_pid["$pid"]="$comm"
    fi
    else
    if printf '%s\n' "$comm" | grep -Eq -- "$pattern"; then
    kill_pids+=("$pid")
    name_by_pid["$pid"]="$comm"
    fi
    fi
    done

    if [ "${#kill_pids[@]}" -eq 0 ]; then
    echo "killgrep: no processes matched pattern on process name: $pattern" >&2
    exit 1
    fi

    if [ "$dry_run" -eq 1 ]; then
    echo "Would send SIG${signal} to the following PIDs (name):"
    for pid in "${kill_pids[@]}"; do
    echo " $pid (${name_by_pid[$pid]})"
    done
    exit 0
    fi

    send_batch() {
    if [[ "$signal" =~ ^[0-9]+$ ]]; then
    kill -"${signal}" -- "${kill_pids[@]}" 2>/dev/null
    else
    kill -s "$signal" -- "${kill_pids[@]}" 2>/dev/null
    fi
    }

    if send_batch; then
    for pid in "${kill_pids[@]}"; do
    echo "Sent SIG${signal} to $pid (${name_by_pid[$pid]})"
    done
    exit 0
    fi

    rc=0
    for pid in "${kill_pids[@]}"; do
    if [[ "$signal" =~ ^[0-9]+$ ]]; then
    if kill -"${signal}" -- "$pid" 2>/dev/null; then
    echo "Sent SIG${signal} to $pid (${name_by_pid[$pid]})"
    else
    echo "Failed to signal $pid (${name_by_pid[$pid]})" >&2
    rc=1
    fi
    else
    if kill -s "$signal" -- "$pid" 2>/dev/null; then
    echo "Sent SIG${signal} to $pid (${name_by_pid[$pid]})"
    else
    echo "Failed to signal $pid (${name_by_pid[$pid]})" >&2
    rc=1
    fi
    fi
    done
    exit $rc