pgrep -f / pkill -f can match the shell that runs them — find processes by PID, not command-line text
With -f, pgrep/pkill match the full command line of every process, including the shell whose own command contains the pattern. pkill -f can kill your own script; prefer PIDs.
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Symptom
A script runs pkill -f my-server and dies itself. Or until ! pgrep -f my-server; do sleep 1; done never exits.
Why (reproduced)
pgrep never matches itself. With -f it matches against every process's full command line, and that includes a parent shell whose command line contains the pattern (bash -c "... pkill -f my-server ..."). In a test, bash -c 'sleep 30 & pgrep -af "sleep 30"' listed the bash -c process as well as the sleep.
Fix
- Track the PID you started:
my-server & echo $! > my-server.pid, and laterkill "$(cat my-server.pid)". - For a network server, find the PID by its listening port:
ss -ltnpH 'sport = :8080'. - Or match the exact process name without
-f:pgrep -x node(usually too broad for scripts). - Before killing anything found by pattern, print what matched (
pgrep -af pattern).
Conditions
- procps_ng
- 4.0.4
- bash
- 5.2.21
- os
- Ubuntu 24.04
- observed
- 2026-09-30
Sources
- pgrep(1) — -f matches against the full command line instead of the process name.