daemonizing in shell (to help me remember)

gistfile1.sh

# my quick and dirty method:

setsid /bin/sh -c "cd /; $@ 2>&1 < /dev/null | logger -t $1 &"

# or the full proper method, found online:

# full daemonization of external command with setsid
daemonize() {
  ( # 1. fork
    # 2.1. redirect stdin/stdout/stderr before setsid. redirect tty fds to /dev/null.
    [[ -t 0 ]] && exec < /dev/null
    [[ -t 1 ]] && exec > /dev/null
    [[ -t 2 ]] && exec 2> /dev/null
    # 3. ensure cwd isn't a mounted fs
    cd /            
    # 4. umask (leave this to caller)
    # umask 0
    # 5. close unneeded fds. close all non-std* fds.
    eval exec {3..255}\>\&-
    # 6. run command
    exec setsid "$@"
    ) &
}

# daemonize without setsid, keeps the child in the jobs table
daemonize-job() {
  ( # 1. fork
    # 2.1. redirect stdin/stdout/stderr before setsid. redirect tty fds to /dev/null.
    [[ -t 0 ]] && exec </dev/null
    [[ -t 1 ]] && exec >/dev/null
    [[ -t 2 ]] && exec 2>/dev/null
    # 2.2.2. guard against HUP and INT (in child)
    trap '' 1 2     # 2.2.2. guard against HUP and INT (in child)
    # 3. ensure cwd isn't a mounted fs
    cd / 
    # 4. umask (leave this to caller)
    # umask 0
    # 5. close unneeded fds. close all non-std* fds.
    eval exec {3..255}\>\&-    
    # 6. run job
    if [[ $(type -t "$1") != file ]]; then
      "$@"
    else
      exec "$@"
    fi
  ) &
  # 2.2.3. guard against HUP (in parent)
  disown -h $!
}