watchd is a process watch dog to keep the watched processes alive.

the sample config file please see src/sample.conf.

config fragment in src/sample.conf:

# one section for a group sub processes
# you can config more than one sections
[test1]

# the type: daemon or cron (for crontab)
# default: daemon
type = daemon

# the mode: all or failover
##  all: run all subprocess_command
##  failover:  run the first command,
##             run the second command when the first exit,
##             run the first command again when the last exit,
##             and so on.
# default: all
mode = failover

# if run by shell as: sh -c command
##  true or 1: run with sh -c command
##  false or 0: run command directly
##  auto: auto detect if need run by sh -c
# default auto
run_by_sh = auto

# force restart interval in seconds
# this parameter only for daemon
# default 0 for never force restart
force_restart_interval = 86400

# set environment variable
# can ocur more than once
set_env = OMP_NUM_THREADS=4

# the command line of sub process
# can be a simple command line or a shell command as following four formats:
##  1. (command)
##  2. command > output_filename  or   command >> output_filename
##  3. command1 | command2 ...
##  4. command &
## the shell command line while be exec as: sh -c command_line
subprocess_command = /bin/echo OMP_NUM_THREADS=$OMP_NUM_THREADS $host_index >> /tmp/echo.log

# check sub process alive interval in seconds
# 0 for never check
check_alive_interval = 10

# retry threshold of check alive
# kill the sub process when the check fail count exceeds this parameter
# default: 3
check_alive_retry_threshold = 3

# check_alive_command can be a command or a library whose filename ends with .so
## the check command output OK for check passed, others for fail
#
## the library must export c function:
##   int check_alive(int argc, char **argv);
##   argv[0] is the library filename, argv[1] is the first parameter and so on.
##   return 0 for success, != 0 for fail.
##
## for example:
##   #@function REPLACE_VARS
##   check_alive_command = /usr/local/lib/libdfscheckalive.so %{encoder_port} 2 30

#@function REPLACE_VARS
check_alive_command = echo OK


[test2]
type = cron
subprocess_command = ls -l / >> /tmp/ls.log

# the time base to schedule
# this parameter only for cron
time_base = 00:00

# repeat interval in seconds
# this parameter only for cron
repeat_interval = 60