Motivation
Submitting jobs often needs more than running scripts in tmux. Jobs may fail silently or run for a long time, and the user cannot keep polling their status.
Makefile
RECEIVER ?= [email protected]
PWD := $(shell pwd)
HOST := $(shell uname -n)
SHELL := /bin/bash
define with_mail
@raw_name='$(if $(strip $(CMD_LABEL)),$(CMD_LABEL),$(CMD))'; \
jobname="$$(printf '%s' "$$raw_name" \
| tr '\n' ' ' \
| sed 's/[[:space:]]\+/ /g; s/^ //; s/ $$//' \
| cut -c1-20)"; \
started="$$(date +%Y%m%dT%H%M%S%Z)"; \
[ -n "$$jobname" ] || name=log; \
log="$(PWD)/$$jobname-$$started.log"; \
set -o pipefail; \
if { $(CMD); } 2>&1 | tee "$$log"; then \
printf '%-6s %s\n' "OK" "$(CMD)"; \
else \
printf '%-6s %s\n' "Err" "$(CMD)"; \
{ \
printf 'Subject: Job %s at %s failed on $(HOST)\n' "$$jobname" "$$started"; \
printf '\n'; \
printf 'Command: $(CMD)\n'; \
printf 'Working dir: $(PWD)\n'; \
printf 'Log file: %s\n' "$$log"; \
printf '\n'; \
printf 'Last 100 lines of log:\n\n'; \
tail -n 100 "$$log"; \
} | sendmail "$(RECEIVER)"; \
fi
endef
The idea is to wrap a shell command in a small helper macro. It does three things:
- gives the job a readable name,
- saves stdout/stderr to a log file,
- emails the user if the job fails.
This is useful for running batch jobs. Compared with running commands directly, this approach keeps the make interface while also preserving a log and a failure notification path.
Example Usage
ifeq ($(V),1)
Q :=
else
Q := @
endif
include mail.mk
.PHONY: test
err: CMD_LABEL = test
err: CMD = echo "hello,world" && exit 42
err:
$(Q)$(with_mail)
ok: CMD = echo "hello,world"
ok:
$(Q)$(with_mail)
The example output email is:
Subject: Job test at 20260307T124008CST failed on adamanteye
Command: echo "hello,world" && exit 42
Working dir: /home/xuelin/test
Log file: /home/xuelin/test/fail-test-20260307T124008CST.log
Last 100 lines of log:
hello,world