1.what is rc_status

The commands from rc.status are actually SuSe specific I think. AFAICT they handle two things: output to the user and the final return status of the script. rc_status checks if the previous command (i.e. the start/restart/stop of a service)executed successfully and sets the "status value", which is the return value returned by rc_exit (which you place at the end of your init.d script). Source

You can conceivably write your shell script without them, but I assume they help making sure that your script conforms to LSB requirements and blends in well with other system scripts. I bet most of this is actually documented in the /etc/rc.status file, though. I just don't have a suse box handy.

2.what is checkproc

http://www.linuxcertif.com/man/8/checkproc/

NAME

Checkproc - Checks for a process by full path name
Pidofproc - Checks for a process by exec base name

SYNOPSIS

checkproc  [ -v ] [ -L ] [ -k ] [ -N ] [ -p   pid_file ] [ -i   ingnore_file ] [ -c   root ] [ -z ]  /full/path/to/executable

checkproc [-v] [-k] [-n] name_of_kernel_thread

pidofproc [-k] basename_of_executable

REQUIRED

/full/path/to/executable or  name_of_kernel_thread

Specifies the executable which processes should be found, or alternatively, if the option Or alternated, if option  -n is used, the name of the  kernel thread. This argument is always required.

EXAMPLE

checkproc /usr/sbin/sendmail returns all pids of running sendmail processes. checkproc -p /var/myrun/lpd.pid /usr/sbin/lpd returns the command line or the basename of the process pid found in  /var/run/lpd.pid.

EXIT CODES

The exit codes without the option  -k  have the following  LSB  conform conditions:

0

Program is running

1

No process but pid file found

3

No process and no pid file found

101

Wrong syntax on command line

102

Other errors

If the option -k is used checkproc uses exit codes like startproc(8) or killproc(8) do:

0

Program is running

1

Generic or unspecified error

2

Invalid or excess argument(s)

4

Insufficient privilege(s)

5

Program is not installed

7

Program is not running

in some cases a message is send to standard error or, if no standard error available, syslogd(8) is used.